Uber SubmitQueue: a high-performance speculative merge queue

Uber's SubmitQueue is a high-speed speculative merge queue designed to maintain a green build at scale. Instead of validating changes one by one, it uses speculative rebasing and parallel validation of multiple changes against predicted versions of HEAD. If the validations succeed, changes are automatically merged. If they fail, SubmitQueue isolates the problematic change and retries the rest without any human involvement.

The queue is tailored for large monorepositories and fast-moving teams, where concurrent modifications can create subtle conflicts and destabilize builds. It includes cross-domain Go code located under platform/, with each product domain having its own tree (submitqueue/, stovepipe/, ...) and eventually expanding into gateway/, orchestrator/, entity/, extension/, and domain-local core/. The importing paths are documented in CLAUDE.md.

To start using SubmitQueue, Docker and Docker Compose are required, along with no other installations. The queue fakes integrations at the edges such as the change provider, CI, and the merge itself, ensuring a free and quick run that takes only seconds. The request log records the full trail from acceptance to landing, and nothing is pushed to any repository.

The Quickstart guide provides details on the change URI, how to intentionally make a change fail, and what this proves. For more extensive testing, e2e-git-test adds a real git merge without credentials, and PROVIDER-E2E.md adds a live provider.

SubmitQueue is still in active development, and both contributions and feedback are welcome. Join the Slack channel submitqueue.slack.com for questions, design discussions, and getting started assistance.