diff --git a/cli.js b/cli.js
index fb0ca9b6f..ef44f64f8 100755
--- a/cli.js
+++ b/cli.js
@@ -2,6 +2,10 @@
 
 'use strict'
 
+process.on('unhandledRejection', (err) => {
+  throw err
+})
+
 const updateNotifier = require('update-notifier')
 const chalk = require('chalk')
 const pkg = require('./package.json')
diff --git a/cmds/publish-rc.js b/cmds/publish-rc.js
new file mode 100644
index 000000000..c454b6eaf
--- /dev/null
+++ b/cmds/publish-rc.js
@@ -0,0 +1,33 @@
+'use strict'
+
+module.exports = {
+  command: 'publish-rc',
+  desc: 'Publish a release candidate',
+  builder: {
+    branch: {
+      describe: 'Where the latest good build is',
+      type: 'string',
+      default: 'build/last-successful'
+    },
+    distTag: {
+      describe: 'The dist tag to publish the rc as',
+      type: 'string',
+      default: 'next'
+    },
+    preId: {
+      describe: 'What to call the rc',
+      type: 'string',
+      default: 'rc'
+    },
+    type: {
+      describe: 'What sort of update this will be',
+      type: 'string',
+      default: 'minor'
+    }
+  },
+  handler (argv) {
+    const publishRc = require('../src/publish-rc')
+    const onError = require('../src/error-handler')
+    publishRc(argv).catch(onError)
+  }
+}
diff --git a/cmds/update-last-successful-build.js b/cmds/update-last-successful-build.js
new file mode 100644
index 000000000..e83c8f7bf
--- /dev/null
+++ b/cmds/update-last-successful-build.js
@@ -0,0 +1,23 @@
+'use strict'
+
+module.exports = {
+  command: 'update-last-successful-build',
+  desc: 'Update last known good build branch',
+  builder: {
+    branch: {
+      describe: 'Which branch to update',
+      type: 'string',
+      default: 'build/last-successful'
+    },
+    message: {
+      describe: 'The message to use when adding the shrinkwrap and yarn.lock file',
+      type: 'string',
+      default: 'chore: add lockfiles'
+    }
+  },
+  handler (argv) {
+    const updateLastPassingBuild = require('../src/update-last-successful-build')
+    const onError = require('../src/error-handler')
+    updateLastPassingBuild(argv).catch(onError)
+  }
+}
diff --git a/src/publish-rc/index.js b/src/publish-rc/index.js
new file mode 100644
index 000000000..aefdd4d2b
--- /dev/null
+++ b/src/publish-rc/index.js
@@ -0,0 +1,65 @@
+'use strict'
+
+const {
+  exec
+} = require('../utils')
+const path = require('path')
+const release = require('../release')
+const semver = require('semver')
+
+async function publishRc (opts) {
+  try {
+    console.info(`Removing local copy of ${opts.branch}`) // eslint-disable-line no-console
+    await exec('git', ['branch', '-D', opts.branch])
+  } catch (err) {
+    if (!err.message.includes(`branch '${opts.branch}' not found`)) {
+      throw err
+    }
+  }
+
+  console.info('Fetching repo history') // eslint-disable-line no-console
+  await exec('git', ['fetch'])
+
+  console.info(`Checking out branch ${opts.branch}`) // eslint-disable-line no-console
+  await exec('git', ['checkout', opts.branch])
+
+  console.info('Reading version number') // eslint-disable-line no-console
+  const pkg = require(path.join(process.cwd(), 'package.json'))
+
+  console.info('Found version number', pkg.version) // eslint-disable-line no-console
+  const version = pkg.version
+  const newVersion = semver.inc(version, opts.type)
+  const newVersionBranch = `v${newVersion.split('.').filter((sub, i) => {
+    return i < 2
+  }).join('.')}.x`
+  console.info('Creating release branch', newVersionBranch) // eslint-disable-line no-console
+
+  await exec('git', ['checkout', '-b', newVersionBranch])
+  await exec('git', ['push', 'origin', `${newVersionBranch}:${newVersionBranch}`])
+
+  if (version.includes('-')) {
+    // already a pre${opts.type}, change from prepatch, preminor, etc to 'prerelease'
+    // e.g. 0.38.0-pre.1 -> 0.38.0-rc.0
+    opts.type = 'release'
+  }
+
+  console.info('Creating', opts.preId) // eslint-disable-line no-console
+  await release({
+    type: `pre${opts.type}`,
+    preid: opts.preId,
+    'dist-tag': opts.distTag,
+    build: false,
+    test: false,
+    lint: false,
+    docsFormats: ['html'],
+    contributors: true,
+    bump: true,
+    changelog: true,
+    publish: true,
+    ghrelease: true,
+    docs: true,
+    ghtoken: process.env.AEGIR_GHTOKEN
+  })
+}
+
+module.exports = publishRc
diff --git a/src/update-last-successful-build/index.js b/src/update-last-successful-build/index.js
new file mode 100644
index 000000000..dc6d53cca
--- /dev/null
+++ b/src/update-last-successful-build/index.js
@@ -0,0 +1,74 @@
+'use strict'
+
+const {
+  exec
+} = require('../utils')
+
+async function findCurrentBranch () {
+  const result = await exec('cat', ['.git/HEAD'])
+
+  return result.stdout.replace('ref: ', '').trim()
+}
+
+async function findMasterCommit () {
+  const result = await exec('git', ['show-ref', '-s', 'origin/master'])
+
+  return result.stdout.trim()
+}
+
+async function isHeadOfMaster () {
+  const master = await findMasterCommit()
+  const branch = await findCurrentBranch()
+
+  // we either have master checked out or a single commit
+  return branch === 'refs/heads/master' || branch === master
+}
+
+async function updateLastSuccessfulBuild (opts) {
+  if (!isHeadOfMaster()) {
+    console.info(`Will only run on the master branch`) // eslint-disable-line no-console
+
+    return
+  }
+
+  console.info('Fetching latest') // eslint-disable-line no-console
+  await exec('git', ['fetch'])
+
+  const tempBranch = 'update-branch-' + Date.now()
+
+  console.info('Creating temp branch') // eslint-disable-line no-console
+  await exec('git', ['checkout', '-b', tempBranch])
+
+  console.info('Creating yarn.lock') // eslint-disable-line no-console
+  await exec('yarn')
+
+  console.info('Creating npm-shrinkwrap.json') // eslint-disable-line no-console
+  await exec('npm', ['shrinkwrap'])
+
+  try {
+    console.info('Committing') // eslint-disable-line no-console
+    await exec('git', ['add', '-f', 'npm-shrinkwrap.json', 'yarn.lock'])
+    await exec('git', ['commit', '-m', opts.message])
+  } catch (err) {
+    if (err.message.includes('nothing to commit, working tree clean')) {
+      console.info('No changes detected, nothing to do') // eslint-disable-line no-console
+      return
+    }
+
+    throw err
+  }
+
+  try {
+    console.info(`Deleting remote ${opts.branch} branch`) // eslint-disable-line no-console
+    await exec('git', ['push', 'origin', `:${opts.branch}`])
+  } catch (err) {
+    if (!err.message.includes('remote ref does not exist')) {
+      throw err
+    }
+  }
+
+  console.info(`Pushing ${opts.branch} branch`) // eslint-disable-line no-console
+  await exec('git', ['push', 'origin', `${tempBranch}:${opts.branch}`])
+}
+
+module.exports = updateLastSuccessfulBuild
diff --git a/src/utils.js b/src/utils.js
index 74b74161d..1b79a53fe 100644
--- a/src/utils.js
+++ b/src/utils.js
@@ -12,6 +12,7 @@ const fs = require('fs-extra')
 const arrify = require('arrify')
 const _ = require('lodash')
 const VerboseRenderer = require('listr-verbose-renderer')
+const execa = require('execa')
 
 const { package: pkg, path: pkgPath } = readPkgUp.sync({
   cwd: fs.realpathSync(process.cwd())
@@ -213,3 +214,12 @@ exports.hook = (env, key) => (ctx) => {
 
   return Promise.resolve()
 }
+
+exports.exec = (command, args) => {
+  const result = execa(command, args)
+
+  result.stdout.pipe(process.stdout)
+  result.stderr.pipe(process.stderr)
+
+  return result
+}