You’ve been building your project as a monorepo on GitHub, but the directory tree now contains components that share little in common. Should you split it up? Below is a side-by-side look at the trade-offs in a U S engineering context, plus guidance for solo developers and real-world practices.
1. Monorepo: Advantages
Benefit
Why It Matters in U S Teams
Consistent codebase
A single source of truth minimizes version skew across micro-services—crucial when CI pipelines (GitHub Actions, CircleCI) run integration tests against all services.
Easy code sharing
Common modules (e.g., logging, feature flags) live once and ship everywhere without publishing private packages to an internal registry.
Simplified dependency management
Package versions are upgraded in one commit, avoiding “dependency hell” across Node, Python, Go, or Rust services.
Atomic changes
Breaking API changes to both a Flask backend and a React frontend can be merged in a single pull request, guaranteeing compatibility at head.
Unified workflow
One CI/CD pipeline (e.g., GitHub Actions → AWS CodeBuild) governs formatting, testing, and deployment, reducing overhead for small or medium-size U S teams.
2. Monorepo: Disadvantages
Drawback
Impact
Longer build/test cycles
Every commit may trigger full-repo checks. Large Go or Java builds can slow engineers unless you add tools like Bazel, TurboRepo, or Nx with affected-only builds.
Repository complexity
Without a clear folder convention (/apps, /libs, /infra), newcomers struggle. Fine-grained branch protection and CODEOWNERS can become messy.
Partial deployment pain
If only a Lambda function changes, bumping the whole repo’s version feels heavy. You’ll need path-filtering in CI or workspace tools to deploy just that piece.
Tooling overhead
At scale (think thousands of engineers at Google), custom solutions—remote build cache, in-house ownership metadata—are mandatory. A solo project rarely needs that, but growth brings this cost.
3. Multirepo: Advantages
Benefit
Why It Matters
Clear boundaries and ownership
Each repo maps to a product or micro-service. Teams own their CI rules and can grant or restrict access via GitHub Teams or Enterprise policies.
Small, fast CI pipelines
Lightweight repositories speed up npm ci, go test, etc., cutting feedback loops especially when running on hosted runners.
Independent releases
A Next.js marketing site can deploy hourly while the core API ships weekly. Rollbacks affect only the service in question.
4. Multirepo: Disadvantages
Drawback
Impact
Code duplication
Shared helpers get copy-pasted unless promoted to an internal artefact repository (e.g., GitHub Packages, AWS CodeArtifact). Maintaining those libraries adds friction for small teams.
Cross-repo changes are clumsy
A gRPC contract change forces synchronized pull requests in two repos—easy to overlook and painful to coordinate across time zones.
Version drift
If the mobile app pins v1 of an auth library while the backend moves to v2, subtle runtime errors ensue. Robust semantic versioning and release notes are essential.
Fragmented reviews & pipelines
Feature work that spans three micro-services means three PRs, three CI runs, and scattered code review discussion threads.
5. Which Structure Favors a Solo Dev & Distributed Deployments?
For a single-developer project with a web frontend, REST API, and background daemon, a monorepo is usually simpler:
Maintenance One repo to open keeps mental overhead low; grep, refactors, and Git history searches span everything.
Synchronized deployments You can ship a breaking change across components with one commit tag and one GitHub Actions workflow that publishes multiple Docker images (e.g., to ECR or GCP Artifact Registry).
Unified tooling A single pre-commit, eslint, ruff, or prettier config avoids per-repo drift.
When to break out repos anyway
Distinct tech stacks or communities (e.g., an open-source iOS SDK vs. a proprietary Kubernetes operator).
Strictly separate compliance domains—public vs. HIPAA-regulated workloads.
Components scheduled for public release on npm, PyPI, etc.
6. U S Industry Examples
Company
Approach
Notes (2025)
Google
Massive monorepo
Still uses Blaze/Bazel and powerful code-search + ownership tooling to manage millions of files.
Meta (Facebook)
Large monorepo (Mercurial)
Buck builds isolate affected targets to keep developer feedback fast.
Netflix
Hybrid
Converging micro-service code tends toward multirepo, but some shared libraries live in consolidated repos.
Uber
Iterated
Started monorepo, split to multirepo during hyper-growth, now uses a mixed model (Go monorepo for some domains).
Startups (YC, seed stage)
Frequently monorepo
Optimize for velocity; split only if ownership boundaries or tooling scale demand it.
Lots of shared models, utilities, or GraphQL schema? monorepo.
Mostly independent services? consider multirepo.
Release cadence
Tight, synchronous releases? monorepo simplifies.
Independent release trains? multirepo shines.
Tooling budget
Willing to add Nx/Bazel and sophisticated caching? monorepo scales.
Prefer out-of-box GitHub CI and minimal custom infra? multirepo keeps things lighter.
8. Bottom Line for Your Current Project
Given that you are the sole maintainer, the convenience of a monorepo outweighs its drawbacks. Stick with it while your project is modest, then reevaluate if contributors multiply or if components diverge significantly in technology or release timing. Flexibility—rather than dogma—will keep your workflow productive as the project evolves.
By Mark 