Multi-Repo to Monorepo: How I Automated 6 Go Microservice Releases and Then Made It 15x Faster

Last month I spent more than an hour cutting a release across six Go microservice repos. Tag log, wait for CI. Update sdk's go.mod to point at the new log SHA, push, wait for CI. Repeat for utils. Then do api, cli, and worker in parallel - except I forgot to bump cli's dependency and the build broke at 11pm. That was the last manual release I did. This is the story of automating that entire workflow with Jenkins + Python + GitLab, then realizing the multi-repo architecture was the real problem, and collapsing everything into a Go monorepo that's 15x faster at cutting releases. The full setup runs on my laptop. You can fork it and try it yourself. Table of Contents The Six Modules The Stack Phase 1: Multi-Repo Automation Phase 2: The Monorepo Pivot The Unified CI Pipeline Real Numbers Caveats and Gotchas Try It Yourself The Six Modules The project simulates a real production system with six Go modules that have strict dependency ordering: Module Role Tag Scheme Depends On log Logger (leaf, no deps) v0.x.0 - sdk API client v0.x.0 log utils Shared utilities v0.x.0 log, sdk api/backend Backend APP-x.y.z log, utils cli CLI cli-x.y.z log, sdk worker Background v0.x.0 log, utils The first three modules are sequential - sdk can't tag until log is tagged, utils can't tag until sdk is tagged. The last three are terminal - they can process in parallel once the sequential chain is done. Every module lives on three long-lived branches: develop → release → master . A release means moving code through all three, in all six repos, in the right order. That's the problem. Do it manually and you're juggling 6 repos × 3 branches × dependency ordering. One forgotten go mod tidy and you're debugging at midnight. The Stack Everything runs on a MacBook. No cloud CI, no SaaS - just local tools wired together. MacBook GitLab.com +-------------------+ ngrok tunnel +------------------------+ | Jenkins LTS | <===============> | Webhooks (push / MR) | | (brew service) | | Commit status API | | :