diff --git a/.github/workflows/sarplus.yml b/.github/workflows/sarplus.yml
new file mode 100644
index 0000000000..e2b3fc6103
--- /dev/null
+++ b/.github/workflows/sarplus.yml
@@ -0,0 +1,159 @@
+# This workflow will run tests and do packaging for contrib/sarplus.
+#
+# References:
+#   * GitHub Actions workflow templates
+#       + [python package](https://github.com/actions/starter-workflows/blob/main/ci/python-package.yml)
+#       + [scala](https://github.com/actions/starter-workflows/blob/main/ci/scala.yml)
+#   * [GitHub hosted runner - Ubuntu 20.04 LTS](https://github.com/actions/virtual-environments/blob/main/images/linux/Ubuntu2004-README.md)
+#   * [Azure Databricks runtime releases](https://docs.microsoft.com/en-us/azure/databricks/release-notes/runtime/releases)
+
+
+name: sarplus test and package
+
+on:
+  push:
+    paths:
+      - contrib/sarplus/python/**
+      - contrib/sarplus/scala/**
+      - contrib/sarplus/VERSION
+      - .github/workflows/sarplus.yml
+
+env:
+  PYTHON_ROOT: ${{ github.workspace }}/contrib/sarplus/python
+  SCALA_ROOT: ${{ github.workspace }}/contrib/sarplus/scala
+
+jobs:
+  python:
+    # Test pysarplus with different versions of Python.
+    # Package pysarplus and upload as GitHub workflow artifact when merged into
+    # the main branch.
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["3.6", "3.7", "3.8", "3.9", "3.10"]
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v2
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Install dependencies
+        run: |
+          python -m pip install -U build pip twine
+          python -m pip install -U flake8 pytest pytest-cov scikit-learn
+
+      - name: Lint with flake8
+        run: |
+          cd "${PYTHON_ROOT}"
+          # See https://flake8.pycqa.org/en/latest/user/index.html
+          flake8 .
+
+      - name: Package and check
+        run: |
+          cd "${PYTHON_ROOT}"
+          cp ../VERSION ./pysarplus/
+          python -m build --sdist
+          python -m twine check dist/*
+
+      - name: Test
+        run: |
+          cd "${PYTHON_ROOT}"
+          python -m pip install dist/*.gz
+
+          cd "${SCALA_ROOT}"
+          export SPARK_VERSION=$(python -m pip show pyspark | grep -i version | cut -d ' ' -f 2)
+          SPARK_JAR_DIR=$(python -m pip show pyspark | grep -i location | cut -d ' ' -f2)/pyspark/jars
+          SCALA_JAR=$(ls ${SPARK_JAR_DIR}/scala-library*)
+          HADOOP_JAR=$(ls ${SPARK_JAR_DIR}/hadoop-client-api*)
+          SCALA_VERSION=${SCALA_JAR##*-}
+          export SCALA_VERSION=${SCALA_VERSION%.*}
+          HADOOP_VERSION=${HADOOP_JAR##*-}
+          export HADOOP_VERSION=${HADOOP_VERSION%.*}
+          sbt ++"${SCALA_VERSION}"! package
+
+          cd "${PYTHON_ROOT}"
+          pytest ./tests
+          echo "sarplus_version=$(cat ../VERSION)" >> $GITHUB_ENV
+
+      - name: Upload Python package as GitHub artifact
+        if: github.ref == 'refs/heads/main' && matrix.python-version == '3.10'
+        uses: actions/upload-artifact@v2
+        with:
+          name: pysarplus-${{ env.sarplus_version }}
+          path: ${{ env.PYTHON_ROOT }}/dist/*.gz
+
+  scala-test:
+    # Test sarplus with different versions of Databricks runtime, 2 LTSs and 1
+    # latest.
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        include:
+          - scala-version: "2.12.10"
+            spark-version: "3.0.1"
+            hadoop-version: "2.7.4"
+            databricks-runtime: "ADB 7.3 LTS"
+
+          - scala-version: "2.12.10"
+            spark-version: "3.1.2"
+            hadoop-version: "2.7.4"
+            databricks-runtime: "ADB 9.1 LTS"
+
+          - scala-version: "2.12.14"
+            spark-version: "3.2.0"
+            hadoop-version: "3.3.1"
+            databricks-runtime: "ADB 10.0"
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Test
+        run: |
+          cd "${SCALA_ROOT}"
+          export SPARK_VERSION="${{ matrix.spark-version }}"
+          export HADOOP_VERSION="${{ matrix.hadoop-version }}"
+          sbt ++${{ matrix.scala-version }}! test
+
+  scala-package:
+    # Package sarplus and upload as GitHub workflow artifact when merged into
+    # the main branch.
+    needs: scala-test
+    if: github.ref == 'refs/heads/main'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Package
+        env:
+          GPG_KEY: ${{ secrets.SARPLUS_GPG_PRI_KEY_ASC }}
+        run: |
+          # generate artifacts
+          cd "${SCALA_ROOT}"
+          export SPARK_VERSION="3.1.2"
+          export HADOOP_VERSION="2.7.4"
+          export SCALA_VERSION="2.12.10"
+          sbt ++${SCALA_VERSION}! package
+          sbt ++${SCALA_VERSION}! packageDoc
+          sbt ++${SCALA_VERSION}! packageSrc
+          sbt ++${SCALA_VERSION}! makePom
+          export SPARK_VERSION="3.2.0"
+          export HADOOP_VERSION="3.3.1"
+          export SCALA_VERSION="2.12.14"
+          sbt ++${SCALA_VERSION}! package
+
+          # sign with GPG
+          cd target/scala-2.12
+          gpg --import <(cat <<< "${GPG_KEY}")
+          for file in {*.jar,*.pom}; do gpg -ab "${file}"; done
+
+          # bundle
+          jar cvf sarplus-bundle_2.12-$(cat ../VERSION).jar *.jar *.pom *.asc
+          echo "sarplus_version=$(cat ../VERSION)" >> $GITHUB_ENV
+          
+      - name: Upload Scala bundle  as GitHub artifact
+        uses: actions/upload-artifact@v2
+        with:
+          name: sarplus-bundle_2.12-${{ env.sarplus_version }}
+          path: ${{ env.SCALA_ROOT }}/target/scala-2.12/sarplus-bundle_2.12-${{ env.sarplus_version }}.jar
diff --git a/AUTHORS.md b/AUTHORS.md
index 1b2e99d19d..18b792d5a0 100644
--- a/AUTHORS.md
+++ b/AUTHORS.md
@@ -103,6 +103,8 @@ To contributors: please add your name to the list when you submit a patch to the
    * Windows test pipelines
 * **[Satyadev Ntv](https://github.com/satyadevntv)**
    * GeoIMC algorithm
+* **[Simon Zhao](https://github.com/simonzhaoms)**
+   * SARplus algorithm upgrade
 * **[Yan Zhang](https://github.com/YanZhangADS)**
    * Diversity metrics including coverage, novelty, diversity, and serendipity
    * Diversity metrics evaluation sample notebook
diff --git a/contrib/sarplus/DEVELOPMENT.md b/contrib/sarplus/DEVELOPMENT.md
index 8d1557cbba..d601be582f 100644
--- a/contrib/sarplus/DEVELOPMENT.md
+++ b/contrib/sarplus/DEVELOPMENT.md
@@ -1,41 +1,109 @@
 # Packaging
 
-For [databricks](https://databricks.com/) to properly install a [C++ extension](https://docs.python.org/3/extending/building.html), one must take a detour through [pypi](https://pypi.org/).
-Use [twine](https://github.com/pypa/twine) to upload the package to [pypi](https://pypi.org/).
+For [databricks](https://databricks.com/) to properly install a [C++
+extension](https://docs.python.org/3/extending/building.html), one
+must take a detour through [pypi](https://pypi.org/).  Use
+[twine](https://github.com/pypa/twine) to upload the package to
+[pypi](https://pypi.org/).
 
 ```bash
-cd python
-
-python setup.py sdist
+# build dependencies
+python -m pip install -U build pip twine
 
-twine upload dist/pysarplus-*.tar.gz
+cd python
+cp ../VERSION ./pysarplus/  # version file
+python -m build --sdist
+python -m twine upload dist/*
 ```
 
-On [Spark](https://spark.apache.org/) one can install all 3 components (C++, Python, Scala) in one pass by creating a [Spark Package](https://spark-packages.org/). Documentation is rather sparse. Steps to install
+On [Spark](https://spark.apache.org/) one can install all 3 components
+(C++, Python, Scala) in one pass by creating a [Spark
+Package](https://spark-packages.org/).  Steps to install
 
 1. Package and publish the [pip package](python/setup.py) (see above)
-2. Package the [Spark package](scala/build.sbt), which includes the [Scala formatter](scala/src/main/scala/microsoft/sarplus) and references the [pip package](scala/python/requirements.txt) (see below)
-3. Upload the zipped Scala package to [Spark Package](https://spark-packages.org/) through a browser. [sbt spPublish](https://github.com/databricks/sbt-spark-package) has a few [issues](https://github.com/databricks/sbt-spark-package/issues/31) so it always fails for me. Don't use spPublishLocal as the packages are not created properly (names don't match up, [issue](https://github.com/databricks/sbt-spark-package/issues/17)) and furthermore fail to install if published to [Spark-Packages.org](https://spark-packages.org/).  
+2. Package the [Spark package](scala/build.sbt), which includes the
+   [Scala formatter](scala/src/main/scala/microsoft/sarplus) and
+   references the pip package (see below)
+3. Upload the zipped Scala package bundle to [Nexus Repository
+   Manager](https://oss.sonatype.org/) through a browser (See [publish
+   manul](https://central.sonatype.org/publish/publish-manual/)).
 
 ```bash
+export SPARK_VERSION="3.1.2"
+export HADOOP_VERSION="2.7.4"
+export SCALA_VERSION="2.12.10"
+GPG_KEY="<gpg-private-key>"
+
+# generate artifacts
 cd scala
-sbt spPublish
+sbt ++${SCALA_VERSION}! package
+sbt ++${SCALA_VERSION}! packageDoc
+sbt ++${SCALA_VERSION}! packageSrc
+sbt ++${SCALA_VERSION}! makePom
+
+# generate the artifact (sarplus-*-spark32.jar) for Spark 3.2+
+export SPARK_VERSION="3.2.0"
+export HADOOP_VERSION="3.3.1"
+export SCALA_VERSION="2.12.14"
+sbt ++${SCALA_VERSION}! package
+
+# sign with GPG
+cd target/scala-${SCALA_VERSION%.*}
+gpg --import <(cat <<< "${GPG_KEY}")
+for file in {*.jar,*.pom}; do gpg -ab "${file}"; done
+
+# bundle
+jar cvf sarplus-bundle_2.12-$(cat ../VERSION).jar *.jar *.pom *.asc
 ```
 
+where `SPARK_VERSION`, `HADOOP_VERSION`, `SCALA_VERSION` should be
+customized as needed.
+
+
 ## Testing
 
 To test the python UDF + C++ backend
 
 ```bash
-cd python 
-python setup.py install && pytest -s tests/
+# build dependencies
+python -m pip install -U build pip twine
+
+# build
+cd python
+cp ../VERSION ./pysarplus/  # version file
+python -m build --sdist
+
+# test
+pytest ./tests
 ```
 
 To test the Scala formatter
 
 ```bash
+export SPARK_VERSION=3.2.0
+export HADOOP_VERSION=3.3.1
+export SCALA_VERSION=2.12.14
+
 cd scala
-sbt test
+sbt ++${SCALA_VERSION}! test
 ```
 
-(use ~test and it will automatically check for changes in source files, but not build.sbt)
+
+## Notes for Spark 3.x  ##
+
+The code now has been modified to support Spark 3.x, and has been
+tested under different versions of Databricks Runtime (including 6.4
+Extended Support, 7.3 LTS, 9.1 LTS, 10.0 and 10.1) on Azure Databricks
+Service.  However, there is a breaking change of
+[org/apache.spark.sql.execution.datasources.OutputWriter](https://github.com/apache/spark/blob/dc0fa1eef74238d745dabfdc86705b59d95b07e1/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/OutputWriter.scala#L74)
+on **Spark 3.2**, which adds an extra function `path()`, so an
+additional JAR file with the classifier `spark32` will be needed if
+running on Spark 3.2 (See above for packaging).
+
+Also, extra configurations are also required when running on Spark
+3.x:
+
+```
+spark.sql.sources.default parquet
+spark.sql.legacy.createHiveTableByDefault true
+```
diff --git a/contrib/sarplus/README.md b/contrib/sarplus/README.md
index d898e2648b..bf27610b19 100644
--- a/contrib/sarplus/README.md
+++ b/contrib/sarplus/README.md
@@ -5,7 +5,13 @@ Pronounced surplus as it's simply better if not best!
 [![Build Status](https://dev.azure.com/best-practices/recommenders/_apis/build/status/contrib%20sarplus?branchName=master)](https://dev.azure.com/best-practices/recommenders/_build/latest?definitionId=107&branchName=master)
 [![PyPI version](https://badge.fury.io/py/pysarplus.svg)](https://badge.fury.io/py/pysarplus)
 
-Simple Algorithm for Recommendation (SAR) is a neighborhood based algorithm for personalized recommendations based on user transaction history. SAR recommends items that are most **similar** to the ones that the user already has an existing **affinity** for. Two items are **similar** if the users that interacted with one item are also likely to have interacted with the other. A user has an **affinity** to an item if they have interacted with it in the past.
+Simple Algorithm for Recommendation (SAR) is a neighborhood based
+algorithm for personalized recommendations based on user transaction
+history. SAR recommends items that are most **similar** to the ones
+that the user already has an existing **affinity** for. Two items are
+**similar** if the users that interacted with one item are also likely
+to have interacted with the other. A user has an **affinity** to an
+item if they have interacted with it in the past.
 
 SARplus is an efficient implementation of this algorithm for Spark.
 
@@ -13,7 +19,8 @@ Features:
 
 * Scalable PySpark based [implementation](python/pysarplus/SARPlus.py)
 * Fast C++ based [predictions](python/src/pysarplus.cpp)
-* Reduced memory consumption: similarity matrix cached in-memory once per worker, shared accross python executors 
+* Reduced memory consumption: similarity matrix cached in-memory once
+  per worker, shared accross python executors
 
 ## Benchmarks
 
@@ -25,15 +32,23 @@ Features:
 
 There are a couple of key optimizations:
 
-* map item ids (e.g. strings) to a continuous set of indexes to optmize storage and simplify access
-* convert similarity matrix to exactly the representation the C++ component needs, thus enabling simple shared, memory mapping of the cache file and avoid parsing. This requires a customer formatter, written in Scala
-* shared read-only memory mapping allows us to re-use the same memory from multiple python executors on the same worker node
-* partition the input test users and past seen items by users, allowing for scale out
+* map item ids (e.g. strings) to a continuous set of indexes to
+  optmize storage and simplify access
+* convert similarity matrix to exactly the representation the C++
+  component needs, thus enabling simple shared, memory mapping of the
+  cache file and avoid parsing. This requires a customer formatter,
+  written in Scala
+* shared read-only memory mapping allows us to re-use the same memory
+  from multiple python executors on the same worker node
+* partition the input test users and past seen items by users,
+  allowing for scale out
 * perform as much of the work as possible in PySpark (way simpler)
 * top-k computation
-** reverse the join by summing reverse joining the users past seen items with any related items
-** make sure to always just keep top-k items in-memory
-** use standard join using binary search between users past seen items and the related items
+    + reverse the join by summing reverse joining the users past seen
+      items with any related items
+    + make sure to always just keep top-k items in-memory
+    + use standard join using binary search between users past seen
+      items and the related items
 
 ![Image of sarplus top-k recommendation optimization](https://recodatasets.z20.web.core.windows.net/images/sarplus_udf.svg)
 
@@ -76,7 +91,7 @@ Insert this cell prior to the code above.
 ```python
 import os
 
-SUBMIT_ARGS = "--packages eisber:sarplus:0.2.6 pyspark-shell"
+SUBMIT_ARGS = "--packages com.microsoft.sarplus:sarplus:0.5.0 pyspark-shell"
 os.environ["PYSPARK_SUBMIT_ARGS"] = SUBMIT_ARGS
 
 from pyspark.sql import SparkSession
@@ -96,21 +111,26 @@ spark = (
 
 ```bash
 pip install pysarplus
-pyspark --packages eisber:sarplus:0.2.6 --conf spark.sql.crossJoin.enabled=true
+pyspark --packages com.microsoft.sarplus:sarplus:0.5.0 --conf spark.sql.crossJoin.enabled=true
 ```
 
 ### Databricks
 
-One must set the crossJoin property to enable calculation of the similarity matrix (Clusters / &lt; Cluster &gt; / Configuration / Spark Config)
+One must set the crossJoin property to enable calculation of the
+similarity matrix (Clusters / &lt; Cluster &gt; / Configuration /
+Spark Config)
 
 ```
 spark.sql.crossJoin.enabled true
+spark.sql.sources.default parquet
+spark.sql.legacy.createHiveTableByDefault true
 ```
 
 1. Navigate to your workspace 
 2. Create library
 3. Under 'Source' select 'Maven Coordinate'
-4. Enter 'eisber:sarplus:0.2.5' or 'eisber:sarplus:0.2.6' if you're on Spark 2.4.1
+4. Enter com.microsoft:sarplus:0.5.0' or
+   microsoft:sarplus:0.5.0:spark32' if you're on Spark 3.2+
 5. Hit 'Create Library'
 6. Attach to your cluster
 7. Create 2nd library
@@ -130,10 +150,10 @@ You'll also have to mount shared storage
 2. Generate new token: enter 'sarplus'
 3. Use databricks shell (installation here)
 4. databricks configure --token
-4.1. Host: e.g. https://westus.azuredatabricks.net
+    1. Host: e.g. https://westus.azuredatabricks.net
 5. databricks secrets create-scope --scope all --initial-manage-principal users
 6. databricks secrets put --scope all --key sarpluscache
-6.1. enter Azure Storage Blob key of Azure Storage created before
+    1. enter Azure Storage Blob key of Azure Storage created before
 7. Run mount code
 
 
@@ -153,4 +173,5 @@ logging.getLogger("py4j").setLevel(logging.ERROR)
 
 ## Development
 
-See [DEVELOPMENT.md](DEVELOPMENT.md) for implementation details and development information.
+See [DEVELOPMENT.md](DEVELOPMENT.md) for implementation details and
+development information.
diff --git a/contrib/sarplus/VERSION b/contrib/sarplus/VERSION
new file mode 100644
index 0000000000..79a2734bbf
--- /dev/null
+++ b/contrib/sarplus/VERSION
@@ -0,0 +1 @@
+0.5.0
\ No newline at end of file
diff --git a/contrib/sarplus/azure-pipelines.yml b/contrib/sarplus/azure-pipelines.yml
deleted file mode 100644
index ae56707d70..0000000000
--- a/contrib/sarplus/azure-pipelines.yml
+++ /dev/null
@@ -1,93 +0,0 @@
-# Python package
-# Create and test a Python package on multiple Python versions.
-# Add steps that analyze code, save the dist with the build record, publish to a PyPI-compatible index, and more:
-# https://docs.microsoft.com/azure/devops/pipelines/languages/python
-
-pr:
-  branches:
-    include:
-      - staging
-      - master
-  paths:
-    include:
-      - contrib/sarplus/*
-
-# no CI trigger
-trigger: none
-
-jobs:
-- job: 'Test'
-  pool:
-    vmImage: 'Ubuntu 16.04'
-  strategy:
-    matrix:
-      Python35-Spark2.3:
-        python.version: '3.5'
-        spark.version: '2.3.0'
-      Python36-Spark2.3:
-        python.version: '3.6'
-        spark.version: '2.3.0'
-      Python35-Spark2.4.1:
-        python.version: '3.5'
-        spark.version: '2.4.1'
-      Python36-Spark2.4.1:
-        python.version: '3.6'
-        spark.version: '2.4.1'
-      Python36-Spark2.4.3:
-        python.version: '3.6'
-        spark.version: '2.4.3'
-      Python37-Spark2.4.3:
-        python.version: '3.7'
-        spark.version: '2.4.3'
-    maxParallel: 4
-
-  steps:
-  - task: ComponentGovernanceComponentDetection@0
-    inputs:
-      scanType: 'Register'
-      verbosity: 'Verbose'
-      alertWarningLevel: 'High'
-      sourceScanPath: contrib/sarplus
-
-  - task: UsePythonVersion@0
-    inputs:
-      versionSpec: '$(python.version)'
-      architecture: 'x64'
-
-  # pyarrow version: https://issues.apache.org/jira/projects/SPARK/issues/SPARK-29367
-  - script: python -m pip install --upgrade pip && pip install pyspark==$(spark.version) pytest pandas pybind11 pyarrow==0.14.1 sklearn
-    displayName: 'Install dependencies'
-
-  - script: |
-      cd contrib/sarplus/scala 
-      sparkversion=$(spark.version) sbt package
-      cd ../python 
-      python setup.py install
-      pytest tests --doctest-modules --junitxml=junit/test-results.xml
-    displayName: 'pytest'
-
-  - script: |
-      cd contrib/sarplus/scala
-      sparkversion=$(spark.version) sbt test
-    displayName: 'scala test'
-
-
-  - task: PublishTestResults@2
-    inputs:
-      testResultsFiles: '**/test-results.xml'
-      testRunTitle: 'Python $(python.version)'
-    condition: succeededOrFailed()
-
-- job: 'Publish'
-  dependsOn: 'Test'
-  pool:
-    vmImage: 'Ubuntu 16.04'
-
-  steps:
-  - task: UsePythonVersion@0
-    inputs:
-      versionSpec: '3.x'
-      architecture: 'x64'
-
-  - script: cd contrib/sarplus/python && python setup.py sdist
-    displayName: 'Build sdist'
diff --git a/contrib/sarplus/python/.flake8 b/contrib/sarplus/python/.flake8
new file mode 100644
index 0000000000..4c042c65b0
--- /dev/null
+++ b/contrib/sarplus/python/.flake8
@@ -0,0 +1,4 @@
+[flake8]
+max-line-length = 120
+ignore = W291
+per-file-ignores = pysarplus/SARPlus.py: E501, pysarplus/__init__.py: F401
\ No newline at end of file
diff --git a/contrib/sarplus/python/README.md b/contrib/sarplus/python/README.md
new file mode 100644
index 0000000000..a280bc7614
--- /dev/null
+++ b/contrib/sarplus/python/README.md
@@ -0,0 +1,13 @@
+# SARplus
+
+Simple Algorithm for Recommendation (SAR) is a neighborhood based
+algorithm for personalized recommendations based on user transaction
+history. SAR recommends items that are most **similar** to the ones
+that the user already has an existing **affinity** for. Two items are
+**similar** if the users that interacted with one item are also likely
+to have interacted with the other. A user has an **affinity** to an
+item if they have interacted with it in the past.
+
+SARplus is an efficient implementation of this algorithm for Spark.
+More details can be found at
+[sarplus@microsoft/recommenders](https://github.com/microsoft/recommenders/tree/main/contrib/sarplus).
diff --git a/contrib/sarplus/python/pyproject.toml b/contrib/sarplus/python/pyproject.toml
new file mode 100644
index 0000000000..415ac9499d
--- /dev/null
+++ b/contrib/sarplus/python/pyproject.toml
@@ -0,0 +1,7 @@
+[build-system]
+requires = [
+    "pybind11",
+    "setuptools>=42",
+    "wheel",
+]
+build-backend = "setuptools.build_meta"
diff --git a/contrib/sarplus/python/pysarplus/SARModel.py b/contrib/sarplus/python/pysarplus/SARModel.py
index bd18c2c88f..afd90cd0f9 100644
--- a/contrib/sarplus/python/pysarplus/SARModel.py
+++ b/contrib/sarplus/python/pysarplus/SARModel.py
@@ -1,3 +1,6 @@
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+
 import pysarplus_cpp
 import os
 
diff --git a/contrib/sarplus/python/pysarplus/SARPlus.py b/contrib/sarplus/python/pysarplus/SARPlus.py
index c372bf82bd..7bb619bf67 100644
--- a/contrib/sarplus/python/pysarplus/SARPlus.py
+++ b/contrib/sarplus/python/pysarplus/SARPlus.py
@@ -1,13 +1,10 @@
-"""
-This is the one and only (to rule them all) implementation of SAR.
-"""
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+"""This is the implementation of SAR."""
 
 import logging
-import pyspark.sql.functions as F
 import pandas as pd
 from pyspark.sql.types import (
-    StringType,
-    DoubleType,
     StructType,
     StructField,
     IntegerType,
@@ -16,6 +13,7 @@
 from pyspark.sql.functions import pandas_udf, PandasUDFType
 from pysarplus import SARModel
 
+
 SIM_COOCCUR = "cooccurrence"
 SIM_JACCARD = "jaccard"
 SIM_LIFT = "lift"
@@ -25,7 +23,7 @@
 
 
 class SARPlus:
-    """SAR implementation for PySpark"""
+    """SAR implementation for PySpark."""
 
     def __init__(
         self,
@@ -41,6 +39,21 @@ def __init__(
         timedecay_formula=False,
         threshold=1,
     ):
+
+        """Initialize model parameters
+        Args:
+            spark (pyspark.sql.SparkSession): Spark session
+            col_user (str): user column name
+            col_item (str): item column name
+            col_rating (str): rating column name
+            col_timestamp (str): timestamp column name
+            table_prefix (str): name prefix of the generated tables
+            similarity_type (str): ['cooccurrence', 'jaccard', 'lift'] option for computing item-item similarity
+            time_decay_coefficient (float): number of days till ratings are decayed by 1/2
+            time_now (int | None): current time for time decay calculation
+            timedecay_formula (bool): flag to apply time decay
+            threshold (int): item-item co-occurrences below this threshold will be removed
+        """
         assert threshold > 0
 
         self.spark = spark
@@ -66,13 +79,15 @@ def f(self, str, **kwargs):
     # current time for time decay calculation
     # cooccurrence matrix threshold
     def fit(self, df):
-        """Main fit method for SAR. Expects the dataframes to have row_id, col_id columns which are indexes,
+        """Main fit method for SAR.
+
+        Expects the dataframes to have row_id, col_id columns which are indexes,
         i.e. contain the sequential integer index of the original alphanumeric user and item IDs.
         Dataframe also contains rating and timestamp as floats; timestamp is in seconds since Epoch by default.
 
         Arguments:
-            df (pySpark.DataFrame): input dataframe which contains the index of users and items. """
-
+            df (pySpark.DataFrame): input dataframe which contains the index of users and items.
+        """
         # threshold - items below this number get set to zero in coocurrence counts
 
         df.createOrReplaceTempView(self.f("{prefix}df_train_input"))
@@ -93,12 +108,12 @@ def fit(self, df):
             query = self.f(
                 """
             SELECT
-                 {col_user}, {col_item},
+                 {col_user}, {col_item}, 
                  SUM({col_rating} * EXP(-log(2) * (latest_timestamp - CAST({col_timestamp} AS long)) / ({time_decay_coefficient} * 3600 * 24))) as {col_rating}
             FROM {prefix}df_train_input,
                  (SELECT CAST(MAX({col_timestamp}) AS long) latest_timestamp FROM {prefix}df_train_input)
-            GROUP BY {col_user}, {col_item}
-            CLUSTER BY {col_user}
+            GROUP BY {col_user}, {col_item} 
+            CLUSTER BY {col_user} 
             """
             )
 
diff --git a/contrib/sarplus/python/pysarplus/__init__.py b/contrib/sarplus/python/pysarplus/__init__.py
index 4e44ba7fe9..0d922d7df1 100644
--- a/contrib/sarplus/python/pysarplus/__init__.py
+++ b/contrib/sarplus/python/pysarplus/__init__.py
@@ -1,2 +1,20 @@
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+
+from pathlib import Path
+
 from .SARModel import SARModel
 from .SARPlus import SARPlus
+
+__title__ = "pysarplus"
+__version__ = (Path(__file__).resolve().parent / "VERSION").read_text().strip()
+__author__ = "RecoDev Team at Microsoft"
+__license__ = "MIT"
+__copyright__ = "Copyright 2018-present Microsoft Corporation"
+
+# Synonyms
+TITLE = __title__
+VERSION = __version__
+AUTHOR = __author__
+LICENSE = __license__
+COPYRIGHT = __copyright__
diff --git a/contrib/sarplus/python/setup.py b/contrib/sarplus/python/setup.py
index bb072fe324..fc1c866189 100644
--- a/contrib/sarplus/python/setup.py
+++ b/contrib/sarplus/python/setup.py
@@ -1,5 +1,9 @@
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+
 import sysconfig
 
+from pathlib import Path
 from setuptools import setup
 from setuptools.extension import Extension
 
@@ -14,35 +18,47 @@ def __str__(self):
         return pybind11.get_include(self.user)
 
 
+DEPENDENCIES = [
+    "numpy",
+    "pandas",
+    "pyarrow>=1.0.0",
+    "pybind11>=2.2",
+    "pyspark>=3.0.0"
+]
+
 setup(
     name="pysarplus",
-    version="0.2.6",
+    version=(Path(__file__).resolve().parent / "pysarplus" / "VERSION").read_text().strip(),
     description="SAR prediction for use with PySpark",
-    url="https://github.com/Microsoft/Recommenders/contrib/sarplus",
-    author="Markus Cozowicz",
-    author_email="marcozo@microsoft.com",
+    long_description=(Path(__file__).resolve().parent / "README.md").read_text(),
+    long_description_content_type='text/markdown',
+    url="https://github.com/microsoft/recommenders/tree/main/contrib/sarplus",
+    author="RecoDev Team at Microsoft",
+    author_email="recodevteam@service.microsoft.com",
     license="MIT",
     classifiers=[
-        "Development Status :: 4 - Beta",
+        "Development Status :: 5 - Production/Stable",
         "License :: OSI Approved :: MIT License",
-        "Programming Language :: Python :: 3.4",
-        "Programming Language :: Python :: 3.5",
         "Programming Language :: Python :: 3.6",
+        "Programming Language :: Python :: 3.7",
+        "Programming Language :: Python :: 3.8",
+        "Programming Language :: Python :: 3.9",
+        "Programming Language :: Python :: 3.10",
         "Intended Audience :: Developers",
         "Intended Audience :: Science/Research",
         "Topic :: Scientific/Engineering :: Mathematics",
     ],
     setup_requires=["pytest-runner"],
-    install_requires=["pybind11>=2.2"],
+    install_requires=DEPENDENCIES,
     tests_require=["pytest"],
     packages=["pysarplus"],
+    package_data={"": ["VERSION"]},
     ext_modules=[
         Extension(
             "pysarplus_cpp",
             ["src/pysarplus.cpp"],
             include_dirs=[get_pybind_include(), get_pybind_include(user=True)],
-            extra_compile_args=sysconfig.get_config_var("CFLAGS").split()
-            + ["-std=c++11", "-Wall", "-Wextra"],
+            extra_compile_args=sysconfig.get_config_var("CFLAGS").split() + ["-std=c++11", "-Wall", "-Wextra"],
             libraries=["stdc++"],
             language="c++11",
         )
diff --git a/contrib/sarplus/python/src/pysarplus.cpp b/contrib/sarplus/python/src/pysarplus.cpp
index 7a5a2739f9..0b06912740 100644
--- a/contrib/sarplus/python/src/pysarplus.cpp
+++ b/contrib/sarplus/python/src/pysarplus.cpp
@@ -1,3 +1,8 @@
+/*
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License.
+ */
+
 #include <pybind11/pybind11.h>
 #include <pybind11/stl.h>
 
diff --git a/contrib/sarplus/python/tests/conftest.py b/contrib/sarplus/python/tests/conftest.py
new file mode 100644
index 0000000000..44efbde4a7
--- /dev/null
+++ b/contrib/sarplus/python/tests/conftest.py
@@ -0,0 +1,83 @@
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+
+import calendar
+import datetime
+import pandas as pd
+import pytest
+
+from sklearn.model_selection import train_test_split
+
+
+@pytest.fixture(scope="module")
+def demo_usage_data(header, sar_settings):
+    # load the data
+    data = pd.read_csv(sar_settings["FILE_DIR"] + "demoUsage.csv")
+    data["rating"] = pd.Series([1] * data.shape[0])
+    data = data.rename(
+        columns={
+            "userId": header["col_user"],
+            "productId": header["col_item"],
+            "rating": header["col_rating"],
+            "timestamp": header["col_timestamp"],
+        }
+    )
+
+    # convert timestamp
+    data[header["col_timestamp"]] = data[header["col_timestamp"]].apply(
+        lambda s: float(
+            calendar.timegm(
+                datetime.datetime.strptime(s, "%Y/%m/%dT%H:%M:%S").timetuple()
+            )
+        )
+    )
+
+    return data
+
+
+@pytest.fixture(scope="module")
+def header():
+    header = {
+        "col_user": "UserId",
+        "col_item": "MovieId",
+        "col_rating": "Rating",
+        "col_timestamp": "Timestamp",
+    }
+    return header
+
+
+@pytest.fixture(scope="module")
+def pandas_dummy(header):
+    ratings_dict = {
+        header["col_user"]: [1, 1, 1, 1, 2, 2, 2, 2, 2, 2],
+        header["col_item"]: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
+        header["col_rating"]: [1, 2, 3, 4, 5, 1, 2, 3, 4, 5],
+    }
+    df = pd.DataFrame(ratings_dict)
+    return df
+
+
+@pytest.fixture(scope="module")
+def pandas_dummy_timestamp(pandas_dummy, header):
+    time = 1535133442
+    time_series = [time + 20 * i for i in range(10)]
+    df = pandas_dummy
+    df[header["col_timestamp"]] = time_series
+    return df
+
+
+@pytest.fixture(scope="module")
+def sar_settings():
+    return {
+        # absolute tolerance parameter for matrix equivalence in SAR tests
+        "ATOL": 1e-8,
+        # directory of the current file - used to link unit test data
+        "FILE_DIR": "https://recodatasets.z20.web.core.windows.net/sarunittest/",
+        # user ID used in the test files (they are designed for this user ID, this is part of the test)
+        "TEST_USER_ID": "0003000098E85347",
+    }
+
+
+@pytest.fixture(scope="module")
+def train_test_dummy_timestamp(pandas_dummy_timestamp):
+    return train_test_split(pandas_dummy_timestamp, test_size=0.2, random_state=0)
diff --git a/contrib/sarplus/python/tests/test_pyspark_sar.py b/contrib/sarplus/python/tests/test_pyspark_sar.py
index f2b85b5e2c..110e469f36 100644
--- a/contrib/sarplus/python/tests/test_pyspark_sar.py
+++ b/contrib/sarplus/python/tests/test_pyspark_sar.py
@@ -1,13 +1,13 @@
-import calendar
-import datetime
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+
 import math
+from pathlib import Path
+
 import numpy as np
 import pandas as pd
-import pytest
-import os
-from sklearn.model_selection import train_test_split
-
 from pyspark.sql import SparkSession
+import pytest
 
 from pysarplus import SARPlus, SARModel
 
@@ -20,7 +20,7 @@ def assert_compare(expected_id, expected_score, actual_prediction):
 
 
 @pytest.fixture(scope="module")
-def spark(app_name="Sample", url="local[*]", memory="1G"):
+def spark(tmp_path_factory, app_name="Sample", url="local[*]", memory="1G"):
     """Start Spark if not started
     Args:
         app_name (str): sets name of the application
@@ -28,19 +28,26 @@ def spark(app_name="Sample", url="local[*]", memory="1G"):
         memory (str): size of memory for spark driver
     """
 
+    try:
+        sarplus_jar_path = next(
+            Path(__file__)
+            .parents[2]
+            .joinpath("scala", "target")
+            .glob("**/sarplus*.jar")
+        ).absolute()
+    except StopIteration:
+        raise Exception("Could not find Sarplus JAR file")
+
     spark = (
         SparkSession.builder.appName(app_name)
         .master(url)
-        .config(
-            "spark.jars",
-            os.path.dirname(__file__)
-            + "/../../scala/target/scala-2.11/sarplus_2.11-0.2.6.jar",
-        )
+        .config("spark.jars", sarplus_jar_path)
         .config("spark.driver.memory", memory)
         .config("spark.sql.shuffle.partitions", "1")
         .config("spark.default.parallelism", "1")
         .config("spark.sql.crossJoin.enabled", True)
         .config("spark.ui.enabled", False)
+        .config("spark.sql.warehouse.dir", str(tmp_path_factory.mktemp("spark")))
         # .config("spark.eventLog.enabled", True) # only for local debugging, breaks on build server
         .getOrCreate()
     )
@@ -59,17 +66,6 @@ def sample_cache(spark):
     return path
 
 
-@pytest.fixture(scope="module")
-def header():
-    header = {
-        "col_user": "UserId",
-        "col_item": "MovieId",
-        "col_rating": "Rating",
-        "col_timestamp": "Timestamp",
-    }
-    return header
-
-
 @pytest.fixture(scope="module")
 def pandas_dummy_dataset(header):
     """Load sample dataset in pandas for testing; can be used to create a Spark dataframe
@@ -177,78 +173,6 @@ def test_e2e(spark, pandas_dummy_dataset, header):
     assert np.allclose(r1.score.values, r2.score.values, 1e-3)
 
 
-@pytest.fixture(scope="module")
-def pandas_dummy(header):
-    ratings_dict = {
-        header["col_user"]: [1, 1, 1, 1, 2, 2, 2, 2, 2, 2],
-        header["col_item"]: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
-        header["col_rating"]: [1, 2, 3, 4, 5, 1, 2, 3, 4, 5],
-    }
-    df = pd.DataFrame(ratings_dict)
-    return df
-
-
-@pytest.fixture(scope="module")
-def pandas_dummy_timestamp(pandas_dummy, header):
-    time = 1535133442
-    time_series = [time + 20 * i for i in range(10)]
-    df = pandas_dummy
-    df[header["col_timestamp"]] = time_series
-    return df
-
-
-@pytest.fixture(scope="module")
-def train_test_dummy_timestamp(pandas_dummy_timestamp):
-    return train_test_split(pandas_dummy_timestamp, test_size=0.2, random_state=0)
-
-
-@pytest.fixture(scope="module")
-def demo_usage_data(header, sar_settings):
-    # load the data
-    data = pd.read_csv(sar_settings["FILE_DIR"] + "demoUsage.csv")
-    data["rating"] = pd.Series([1] * data.shape[0])
-    data = data.rename(
-        columns={
-            "userId": header["col_user"],
-            "productId": header["col_item"],
-            "rating": header["col_rating"],
-            "timestamp": header["col_timestamp"],
-        }
-    )
-
-    # convert timestamp
-    data[header["col_timestamp"]] = data[header["col_timestamp"]].apply(
-        lambda s: float(
-            calendar.timegm(
-                datetime.datetime.strptime(s, "%Y/%m/%dT%H:%M:%S").timetuple()
-            )
-        )
-    )
-
-    return data
-
-
-@pytest.fixture(scope="module")
-def demo_usage_data_spark(spark, demo_usage_data, header):
-    data_local = demo_usage_data[[x[1] for x in header.items()]]
-    # TODO: install pyArrow in DS VM
-    # spark.conf.set("spark.sql.execution.arrow.enabled", "true")
-    data = spark.createDataFrame(data_local)
-    return data
-
-
-@pytest.fixture(scope="module")
-def sar_settings():
-    return {
-        # absolute tolerance parameter for matrix equivalence in SAR tests
-        "ATOL": 1e-8,
-        # directory of the current file - used to link unit test data
-        "FILE_DIR": "http://recodatasets.blob.core.windows.net/sarunittest/",
-        # user ID used in the test files (they are designed for this user ID, this is part of the test)
-        "TEST_USER_ID": "0003000098E85347",
-    }
-
-
 @pytest.mark.parametrize(
     "similarity_type, timedecay_formula", [("jaccard", False), ("lift", True)]
 )
@@ -259,7 +183,7 @@ def test_fit(
         spark,
         **header,
         timedecay_formula=timedecay_formula,
-        similarity_type=similarity_type
+        similarity_type=similarity_type,
     )
 
     trainset, testset = train_test_dummy_timestamp
@@ -276,6 +200,7 @@ def test_fit(
 Main SAR tests are below - load test files which are used for both Scala SAR and Python reference implementations
 """
 
+
 # Tests 1-6
 @pytest.mark.parametrize(
     "threshold,similarity_type,file",
@@ -289,7 +214,13 @@ def test_fit(
     ],
 )
 def test_sar_item_similarity(
-    spark, threshold, similarity_type, file, demo_usage_data, sar_settings, header
+    spark,
+    threshold,
+    similarity_type,
+    file,
+    demo_usage_data,
+    sar_settings,
+    header,
 ):
 
     model = SARPlus(
@@ -299,7 +230,7 @@ def test_sar_item_similarity(
         time_decay_coefficient=30,
         time_now=None,
         threshold=threshold,
-        similarity_type=similarity_type
+        similarity_type=similarity_type,
     )
 
     df = spark.createDataFrame(demo_usage_data)
@@ -339,7 +270,9 @@ def test_sar_item_similarity(
         )
 
         assert np.allclose(
-            item_similarity.value.values, item_similarity_ref.value.values
+            item_similarity.value.values,
+            item_similarity_ref.value.values,
+            atol=sar_settings["ATOL"],
         )
 
 
@@ -353,7 +286,7 @@ def test_user_affinity(spark, demo_usage_data, sar_settings, header):
         timedecay_formula=True,
         time_decay_coefficient=30,
         time_now=time_now,
-        similarity_type="cooccurrence"
+        similarity_type="cooccurrence",
     )
 
     df = spark.createDataFrame(demo_usage_data)
@@ -393,7 +326,14 @@ def test_user_affinity(spark, demo_usage_data, sar_settings, header):
     [(3, "cooccurrence", "count"), (3, "jaccard", "jac"), (3, "lift", "lift")],
 )
 def test_userpred(
-    spark, threshold, similarity_type, file, header, sar_settings, demo_usage_data
+    spark,
+    tmp_path,
+    threshold,
+    similarity_type,
+    file,
+    header,
+    sar_settings,
+    demo_usage_data,
 ):
     time_now = demo_usage_data[header["col_timestamp"]].max()
 
@@ -407,19 +347,13 @@ def test_userpred(
         time_decay_coefficient=30,
         time_now=time_now,
         threshold=threshold,
-        similarity_type=similarity_type
+        similarity_type=similarity_type,
     )
 
     df = spark.createDataFrame(demo_usage_data)
     model.fit(df)
 
-    url = (
-        sar_settings["FILE_DIR"]
-        + "userpred_"
-        + file
-        + str(threshold)
-        + "_userid_only.csv"
-    )
+    url = sar_settings["FILE_DIR"] + "userpred_" + file + str(threshold) + "_userid_only.csv"
 
     pred_ref = pd.read_csv(url)
     pred_ref = (
@@ -428,14 +362,14 @@ def test_userpred(
         .reset_index(drop=True)
     )
 
-    # Note: it's important to have a separate cache_path for each run as they're interferring with each other
+    # Note: it's important to have a separate cache_path for each run as they're interfering with each other
     pred = model.recommend_k_items(
         spark.createDataFrame(
             demo_usage_data[
                 demo_usage_data[header["col_user"]] == sar_settings["TEST_USER_ID"]
             ]
         ),
-        cache_path="test_userpred-" + test_id,
+        cache_path=str(tmp_path.joinpath("test_userpred-" + test_id)),
         top_k=10,
         n_user_prediction_partitions=1,
     )
diff --git a/contrib/sarplus/scala/build.sbt b/contrib/sarplus/scala/build.sbt
index f79cb49a43..7c573270d6 100644
--- a/contrib/sarplus/scala/build.sbt
+++ b/contrib/sarplus/scala/build.sbt
@@ -1,30 +1,93 @@
-scalaVersion := "2.11.8"
+/*
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License.
+ */
 
-sparkVersion := sys.env.get("sparkversion").getOrElse("2.3.0")
-
-spName := "microsoft/sarplus"
-
-organization := "microsoft"
 name := "sarplus"
 
-version := "0.2.6" 
+// Denpendency configuration
 
-sparkComponents ++= Seq("core", "sql", "mllib")
+lazy val sparkVer = settingKey[String]("spark version")
+lazy val hadoopVer = settingKey[String]("hadoop version")
 
-libraryDependencies ++= Seq(
-  "commons-io" % "commons-io" % "2.6",
-  "com.google.guava" % "guava" % "25.0-jre",
-  "org.scalatest" %% "scalatest" % "3.0.5" % "test",
-  "org.scalamock" %% "scalamock" % "4.1.0" % "test"
+lazy val commonSettings = Seq(
+  organization := "sarplus.microsoft",
+  version := IO.read(new File("../VERSION")),
+  resolvers ++= Seq(
+    Resolver.sonatypeRepo("snapshots"),
+    Resolver.sonatypeRepo("releases"),
+  ),
+  addCompilerPlugin("org.scalamacros" % "paradise" % "2.1.1" cross CrossVersion.full),
+  sparkVer := sys.env.getOrElse("SPARK_VERSION", "3.2.0"),
+  hadoopVer := sys.env.getOrElse("HADOOP_VERSION", "3.3.1"),
+  libraryDependencies ++= Seq(
+    "com.fasterxml.jackson.core" % "jackson-databind" % "2.12.2",
+    "commons-io" % "commons-io" % "2.8.0",
+    "org.apache.hadoop" % "hadoop-common" % hadoopVer.value,
+    "org.apache.hadoop" % "hadoop-hdfs" % hadoopVer.value,
+    "org.apache.spark" %% "spark-core" % sparkVer.value,
+    "org.apache.spark" %% "spark-mllib" % sparkVer.value,
+    "org.apache.spark" %% "spark-sql" % sparkVer.value,
+    "org.scala-lang" % "scala-reflect" % scalaVersion.value,
+    "com.google.guava" % "guava" % "15.0",
+    "org.scalamock" %% "scalamock" % "4.1.0" % "test",
+    "org.scalatest" %% "scalatest" % "3.0.8" % "test",
+    "xerces" % "xercesImpl" % "2.12.1",
+  ),
+  Compile / packageBin / artifact := {
+    val prev: Artifact = (Compile / packageBin / artifact).value
+    prev.withClassifier(
+        prev.classifier match {
+          case None => {
+            val splitVer = sparkVer.value.split('.')
+            val major = splitVer(0).toInt
+            val minor = splitVer(1).toInt
+            if (major >=3 && minor >= 2) Some("spark32") else None
+          }
+          case Some(s: String) => Some(s)
+        }
+    )
+  },
 )
 
-// All Spark Packages need a license
-licenses := Seq("MIT" -> url("http://opensource.org/licenses/MIT"))
+lazy val compat = project.settings(commonSettings)
+lazy val root = (project in file("."))
+  .dependsOn(compat)
+  .settings(
+    name := "sarplus",
+    commonSettings,
+  )
 
-// doesn't work anyway...
-credentials += Credentials(Path.userHome / ".ivy2" / ".sbtcredentials") // A file containing credentials
 
-spHomepage := "http://github.com/Microsoft/Recommenders/contrib/sarplus"
+// POM metadata configuration.  See https://www.scala-sbt.org/release/docs/Using-Sonatype.html
 
-// If you published your package to Maven Central for this release (must be done prior to spPublish)
-spIncludeMaven := true
+organization := "com.microsoft.sarplus"
+organizationName := "microsoft"
+organizationHomepage := Some(url("https://microsoft.com"))
+
+scmInfo := Some(
+  ScmInfo(
+    url("https://github.com/microsoft/recommenders/tree/main/contrib/sarplus"),
+    "scm:git@github.com:microsoft/recommenders.git"
+  )
+)
+
+developers := List(
+  Developer(
+    id = "recodev",
+    name = "RecoDev Team at Microsoft",
+    email = "recodevteam@service.microsoft.com",
+    url = url("https://github.com/microsoft/recommenders/")
+  )
+)
+
+description := "sarplus"
+licenses := Seq("MIT" -> url("http://opensource.org/licenses/MIT"))
+homepage := Some(url("https://github.com/microsoft/recommenders/tree/main/contrib/sarplus"))
+pomIncludeRepository := { _ => false }
+publishTo := {
+  val nexus = "https://oss.sonatype.org/"
+  if (isSnapshot.value) Some("snapshots" at nexus + "content/repositories/snapshots")
+  else Some("releases" at nexus + "service/local/staging/deploy/maven2")
+}
+publishMavenStyle := true
diff --git a/contrib/sarplus/scala/compat/src/main/scala/com/microsoft/sarplus/compat/spark/since3p2defvisible.scala b/contrib/sarplus/scala/compat/src/main/scala/com/microsoft/sarplus/compat/spark/since3p2defvisible.scala
new file mode 100644
index 0000000000..780581d4e5
--- /dev/null
+++ b/contrib/sarplus/scala/compat/src/main/scala/com/microsoft/sarplus/compat/spark/since3p2defvisible.scala
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License.
+ */
+
+package com.microsoft.sarplus.spark
+
+import scala.annotation.{StaticAnnotation, compileTimeOnly}
+import scala.language.experimental.macros
+import scala.reflect.macros.Context
+
+import util.Properties.versionNumberString
+
+@compileTimeOnly("enable macro paradise to expand macro annotations")
+class since3p2defvisible extends StaticAnnotation {
+  def macroTransform(annottees: Any*): Any = macro since3p2defvisibleMacro.impl
+}
+
+object since3p2defvisibleMacro {
+  def impl(c: Context)(annottees: c.Tree*) = {
+    import c.universe._
+    annottees match {
+      case q"$mods def $name[..$tparams](...$paramss): $tpt = $body" :: tail =>
+        // NOTE: There seems no way to find out the Spark version.
+        val major = versionNumberString.split('.')(0).toInt
+        val minor = versionNumberString.split('.')(1).toInt
+        val patch = versionNumberString.split('.')(2).toInt
+        if (major >= 2 && minor >= 12 && patch >= 14) {
+          q"""
+            $mods def $name[..$tparams](...$paramss): $tpt =
+              $body
+          """
+        } else {
+          q""
+        }
+      case _ => throw new IllegalArgumentException("Please annotate a method")
+    }
+  }
+}
diff --git a/contrib/sarplus/scala/project/build.properties b/contrib/sarplus/scala/project/build.properties
index 133a8f197e..10fd9eee04 100644
--- a/contrib/sarplus/scala/project/build.properties
+++ b/contrib/sarplus/scala/project/build.properties
@@ -1 +1 @@
-sbt.version=0.13.17
+sbt.version=1.5.5
diff --git a/contrib/sarplus/scala/project/plugins.sbt b/contrib/sarplus/scala/project/plugins.sbt
index f1495154b8..0a8aeeaba2 100644
--- a/contrib/sarplus/scala/project/plugins.sbt
+++ b/contrib/sarplus/scala/project/plugins.sbt
@@ -1,4 +1,3 @@
-// You may use this file to add plugin dependencies for sbt.
-resolvers += "Spark Package Main Repo" at "https://dl.bintray.com/spark-packages/maven"
-
-addSbtPlugin("org.spark-packages" %% "sbt-spark-package" % "0.2.6")
+addSbtPlugin("no.arktekk.sbt" % "aether-deploy" % "0.27.0")
+addSbtPlugin("org.scoverage" % "sbt-scoverage" % "1.9.1")
+addSbtPlugin("com.github.sbt" % "sbt-pgp" % "2.1.2")
diff --git a/contrib/sarplus/scala/python/pysarplus_dummy/__init__.py b/contrib/sarplus/scala/python/pysarplus_dummy/__init__.py
index aa0be35f48..0720a92163 100644
--- a/contrib/sarplus/scala/python/pysarplus_dummy/__init__.py
+++ b/contrib/sarplus/scala/python/pysarplus_dummy/__init__.py
@@ -1 +1,4 @@
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+
 installed = 1
diff --git a/contrib/sarplus/scala/python/setup.py b/contrib/sarplus/scala/python/setup.py
index 49a0dc8b59..9821b294c9 100644
--- a/contrib/sarplus/scala/python/setup.py
+++ b/contrib/sarplus/scala/python/setup.py
@@ -1,11 +1,15 @@
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+
 from distutils.core import setup
+import os
 
 setup(
     name="pysarplus_dummy",
-    version="0.2",
+    version=(Path(__file__).resolve().parent.parent.parent / "VERSION").read_text().strip(),
     description="pysarplus dummy package to trigger spark packaging",
-    author="Markus Cozowicz",
-    author_email="marcozo@microsoft.com",
+    author="RecoDev Team at Microsoft",
+    author_email="recodevteam@service.microsoft.com",
     url="https://github.com/Microsoft/Recommenders/contrib/sarplus",
     packages=["pysarplus_dummy"],
 )
diff --git a/contrib/sarplus/scala/src/main/scala/com/microsoft/sarplus/DefaultSource.scala b/contrib/sarplus/scala/src/main/scala/com/microsoft/sarplus/DefaultSource.scala
index c693e870ad..f7a1da5376 100644
--- a/contrib/sarplus/scala/src/main/scala/com/microsoft/sarplus/DefaultSource.scala
+++ b/contrib/sarplus/scala/src/main/scala/com/microsoft/sarplus/DefaultSource.scala
@@ -1,3 +1,8 @@
+/*
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License.
+ */
+
 package com.microsoft.sarplus
 
 import org.apache.spark.sql.sources.DataSourceRegister
diff --git a/contrib/sarplus/scala/src/main/scala/com/microsoft/sarplus/SARCacheOutputWriter.scala b/contrib/sarplus/scala/src/main/scala/com/microsoft/sarplus/SARCacheOutputWriter.scala
index 7f8f8d446f..49c924c6c7 100644
--- a/contrib/sarplus/scala/src/main/scala/com/microsoft/sarplus/SARCacheOutputWriter.scala
+++ b/contrib/sarplus/scala/src/main/scala/com/microsoft/sarplus/SARCacheOutputWriter.scala
@@ -1,3 +1,8 @@
+/*
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License.
+ */
+
 package com.microsoft.sarplus
 
 import java.io.{DataOutputStream, FileInputStream, FileOutputStream, BufferedOutputStream, OutputStream}
@@ -11,8 +16,10 @@ import org.apache.spark.sql.types._
 import org.apache.commons.io.IOUtils
 import com.google.common.io.LittleEndianDataOutputStream
 
+import com.microsoft.sarplus.spark.since3p2defvisible
+
 class SARCacheOutputWriter(
-    path: String,
+    filePath: String,
     outputStream: OutputStream,
     schema: StructType) extends OutputWriter
 {
@@ -20,8 +27,8 @@ class SARCacheOutputWriter(
   if (schema.length < 3)
     throw new IllegalArgumentException("Schema must have at least 3 fields")
 
-  val pathOffset = path + ".offsets"
-  val pathRelated = path + ".related"
+  val pathOffset = filePath + ".offsets"
+  val pathRelated = filePath + ".related"
 
   // temporary output files
   val tempOutputOffset = new LittleEndianDataOutputStream(new BufferedOutputStream(new FileOutputStream(pathOffset), 8*1024))
@@ -44,7 +51,7 @@ class SARCacheOutputWriter(
 
     if(lastId != i1)
     {
-        tempOutputOffset.writeLong(rowNumber) 
+        tempOutputOffset.writeLong(rowNumber)
         offsetCount += 1
         lastId = i1
     }
@@ -64,7 +71,7 @@ class SARCacheOutputWriter(
 
     if(lastId != i1)
     {
-        tempOutputOffset.writeLong(rowNumber) 
+        tempOutputOffset.writeLong(rowNumber)
         offsetCount += 1
         lastId = i1
     }
@@ -75,7 +82,7 @@ class SARCacheOutputWriter(
     rowNumber += 1
   }
 
-  override def close(): Unit = 
+  override def close(): Unit =
   {
       tempOutputOffset.writeLong(rowNumber)
       offsetCount += 1
@@ -94,5 +101,8 @@ class SARCacheOutputWriter(
       input.close
 
       outputFinal.close
-  } 
+  }
+
+  @since3p2defvisible
+  override def path(): String = filePath
 }
diff --git a/contrib/sarplus/scala/src/main/scala/com/microsoft/sarplus/SARCacheOutputWriterFactory.scala b/contrib/sarplus/scala/src/main/scala/com/microsoft/sarplus/SARCacheOutputWriterFactory.scala
index 71d1e44f37..2e41effa3a 100644
--- a/contrib/sarplus/scala/src/main/scala/com/microsoft/sarplus/SARCacheOutputWriterFactory.scala
+++ b/contrib/sarplus/scala/src/main/scala/com/microsoft/sarplus/SARCacheOutputWriterFactory.scala
@@ -1,3 +1,8 @@
+/*
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License.
+ */
+
 package com.microsoft.sarplus
 
 import org.apache.hadoop.mapreduce.TaskAttemptContext
diff --git a/contrib/sarplus/scala/src/test/scala/com/microsoft/sarplus/SARCacheOutputWriterSpec.scala b/contrib/sarplus/scala/src/test/scala/com/microsoft/sarplus/SARCacheOutputWriterSpec.scala
index 5eadfd8012..7565965e80 100644
--- a/contrib/sarplus/scala/src/test/scala/com/microsoft/sarplus/SARCacheOutputWriterSpec.scala
+++ b/contrib/sarplus/scala/src/test/scala/com/microsoft/sarplus/SARCacheOutputWriterSpec.scala
@@ -1,3 +1,8 @@
+/*
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License.
+ */
+
 package com.microsoft.sarplus
 
 import org.scalatest._