add ffe server sdk landing page and stubs for each language

config/_default/menus/main.en.yaml

@@ -5582,21 +5582,51 @@ menu:
       parent: software_delivery_heading
       identifier: feature_flags
       weight: 80000
-    - name: Setup
-      url: feature_flags/setup
+    - name: Client SDKs
+      url: feature_flags/client
       parent: feature_flags
-      identifier: feature_flags_setup
+      identifier: feature_flags_client
       weight: 1
     - name: Android and Android TV
-      url: feature_flags/setup/android
-      parent: feature_flags_setup
-      identifier: feature_flags_setup_android
+      url: feature_flags/client/android
+      parent: feature_flags_client
+      identifier: feature_flags_client_android
       weight: 101
     - name: iOS and tvOS
-      url: feature_flags/setup/ios
-      parent: feature_flags_setup
-      identifier: feature_flags_setup_ios
+      url: feature_flags/client/ios
+      parent: feature_flags_client
+      identifier: feature_flags_client_ios
       weight: 102
+    - name: Server SDKs
+      url: feature_flags/server
+      parent: feature_flags
+      identifier: feature_flags_server
+      weight: 2
+    - name: Go
+      url: feature_flags/server/go
+      parent: feature_flags_server
+      identifier: feature_flags_server_go
+      weight: 201
+    - name: Java
+      url: feature_flags/server/java
+      parent: feature_flags_server
+      identifier: feature_flags_server_java
+      weight: 202
+    - name: Node.js
+      url: feature_flags/server/nodejs
+      parent: feature_flags_server
+      identifier: feature_flags_server_nodejs
+      weight: 203
+    - name: Python
+      url: feature_flags/server/python
+      parent: feature_flags_server
+      identifier: feature_flags_server_python
+      weight: 204
+    - name: Ruby
+      url: feature_flags/server/ruby
+      parent: feature_flags_server
+      identifier: feature_flags_server_ruby
+      weight: 205
     - name: MCP Server
       url: feature_flags/feature_flag_mcp_server
       parent: feature_flags

content/en/feature_flags/_index.md

@@ -5,9 +5,12 @@ further_reading:
 - link: "/getting_started/feature_flags/"
   tag: "Documentation"
   text: "Getting started with Feature Flags"
-- link: "/feature_flags/setup/"
+- link: "/feature_flags/client/"
   tag: "Documentation"
-  text: "Set up Feature Flags for your applications"
+  text: "Set up Feature Flags for client-side applications"
+- link: "/feature_flags/server/"
+  tag: "Documentation"
+  text: "Set up Feature Flags for server-side applications"
 - link: "/feature_flags/guide/migrate_from_statsig"
   tag: "Guide"
   text: "Migrate Your Feature Flags from Statsig"

content/en/feature_flags/setup/_index.md → content/en/feature_flags/client/_index.md

@@ -1,13 +1,18 @@
 ---
-title: Set Up Feature Flags
-description: Set up Datadog Feature Flags for your mobile applications.
+title: Client-Side Feature Flags
+description: Set up Datadog Feature Flags for client-side applications.
+aliases:
+  - /feature_flags/setup/
 further_reading:
 - link: "/feature_flags/"
   tag: "Documentation"
   text: "Learn about Feature Flags"
 - link: "/getting_started/feature_flags/"
   tag: "Documentation"
   text: "Getting Started with Feature Flags"
+- link: "feature_flags/server/"
+  tag: "Documentation"
+  text: "Server-Side Feature Flags"
 ---
 
 {{< callout url="http://datadoghq.com/product-preview/feature-flags/" >}}
@@ -18,7 +23,7 @@ Feature Flags are in Preview. Complete the form to request access.
 
 Set up Datadog Feature Flags for your applications. Follow the platform-specific guides below to integrate feature flags into your application and start collecting feature flag data:
 
-{{< partial name="feature_flags/feature_flags_setup.html" >}}
+{{< partial name="feature_flags/feature_flags_client.html" >}}
 
 ## Further reading
 

content/en/feature_flags/setup/android.md → content/en/feature_flags/client/android.md

@@ -1,10 +1,12 @@
 ---
 title: Android and Android TV Feature Flags
 description: Set up Datadog Feature Flags for Android and Android TV applications.
+aliases:
+  - /feature_flags/setup/android/
 further_reading:
-- link: "/feature_flags/setup/"
+- link: "/feature_flags/client/"
   tag: "Documentation"
-  text: "Feature Flags Setup"
+  text: "Client-Side Feature Flags"
 - link: "/real_user_monitoring/android/"
   tag: "Documentation"
   text: "Android and Android TV Monitoring"

content/en/feature_flags/setup/ios.md → content/en/feature_flags/client/ios.md

@@ -1,10 +1,12 @@
 ---
 title: iOS and tvOS Feature Flags
 description: Set up Datadog Feature Flags for iOS and tvOS applications.
+aliases:
+  - /feature_flags/setup/ios/
 further_reading:
-- link: "/feature_flags/setup/"
+- link: "/feature_flags/client/"
   tag: "Documentation"
-  text: "Feature Flags Setup"
+  text: "Client-Side Feature Flags"
 - link: "/real_user_monitoring/ios/"
   tag: "Documentation"
   text: "iOS and tvOS Monitoring"

content/en/feature_flags/server/_index.md

@@ -0,0 +1,72 @@
+---
+title: Server-Side Feature Flags
+description: Set up Datadog Feature Flags for server-side applications.
+further_reading:
+- link: "/feature_flags/client/"
+  tag: "Documentation"
+  text: "Client-Side Feature Flags"
+- link: "/remote_configuration/"
+  tag: "Documentation"
+  text: "Remote Configuration"
+---
+
+{{< callout url="http://datadoghq.com/product-preview/feature-flags/" >}}
+Feature Flags are in Preview. Complete the form to request access.
+{{< /callout >}}
+
+## Overview
+
+Datadog Feature Flags for server-side applications allow you to remotely control feature availability, run experiments, and roll out new functionality with confidence. Server-side SDKs integrate with the Datadog APM tracer and use Remote Configuration to receive flag updates in real time.
+
+This guide covers the common setup required for all server-side SDKs, including Agent configuration and application environment variables. Select your language or framework to view SDK-specific setup instructions:
+
+{{< partial name="feature_flags/feature_flags_server.html" >}}
+
+## Prerequisites
+
+Before setting up server-side feature flags, ensure you have:
+
+- **Datadog Agent 7.55 or later** installed and running
+- **Datadog API key** configured
+- **APM tracing** enabled in your application
+
+## Agent configuration
+
+Server-side feature flags use [Remote Configuration][1] to deliver flag configurations to your application. Enable Remote Configuration in your Datadog Agent by setting `DD_REMOTE_CONFIGURATION_ENABLED=true` or adding `remote_configuration.enabled: true` to your `datadog.yaml`.
+
+See the [Remote Configuration documentation][1] for detailed setup instructions across different deployment environments.
+
+### Polling interval
+
+The Agent polls Datadog for configuration updates at a configurable interval. This interval determines the average time between making a flag change in the UI and the change becoming available to your application.
+
+{{< code-block lang="bash" >}}
+# Optional: Configure polling interval (default: 60s)
+DD_REMOTE_CONFIGURATION_REFRESH_INTERVAL=10s
+{{< /code-block >}}
+
+[1]: /remote_configuration
+
+## Application configuration
+
+Configure your application with the standard Datadog environment variables. These are common across all server-side SDKs:
+
+{{< code-block lang="bash" >}}
+# Required: Service identification
+DD_SERVICE=<YOUR_SERVICE_NAME>
+DD_ENV=<YOUR_ENVIRONMENT>
+DD_VERSION=<YOUR_APP_VERSION>
+
+# Agent connection (if not using default localhost:8126)
+DD_AGENT_HOST=localhost
+DD_TRACE_AGENT_PORT=8126
+
+# Enable Remote Configuration in the tracer
+DD_REMOTE_CONFIG_ENABLED=true
+{{< /code-block >}}
+
+<div class="alert alert-info">Some SDKs require additional experimental flags to enable feature flagging. See the SDK-specific documentation for details.</div>
+
+## Further reading
+
+{{< partial name="whats-next/whats-next.html" >}}