Monorepos vs Polyrepos
As organizations grow, how you organize your code repositories becomes critical. Monorepos and polyrepos represent two philosophies, each with distinct DevOps implications for build times, CI/CD pipelines, and team autonomy.
Monorepo vs Polyrepo
- Monorepo: All projects in one repository. Used by Google (2 billion lines!), Facebook, Twitter
- Polyrepo: Each service/project has its own repository. Used by Amazon, Netflix (older)
- Monorepo advantages: atomic cross-service commits, shared tooling, easy code sharing, single CI config
- Monorepo challenges: large repo (slow clone), complex CI (must avoid building everything on every change)
- Polyrepo advantages: team autonomy, faster CI (small repos), clear ownership boundaries
- Polyrepo challenges: dependency management hell, coordinating cross-repo changes, duplicated configs
Nx Monorepo Tool
# Nx - the leading monorepo tool for JavaScript/TypeScript
# Create an Nx workspace
npx create-nx-workspace@latest my-org
# Select: integrated monorepo
# Structure:
# my-org/
# ├── apps/
# │ ├── web-app/ # Next.js frontend
# │ ├── api/ # Node.js backend
# │ └── mobile/ # React Native app
# ├── libs/
# │ ├── shared-ui/ # Shared component library
# │ ├── auth/ # Shared auth utilities
# │ └── data-access/ # Shared API client
# └── nx.json # Nx configuration
# The magic: Nx only builds/tests what CHANGED
# On PR that only touches apps/web-app:
# ✓ web-app: build + test (changed)
# ✓ shared-ui: test (web-app depends on it)
# ✗ api: SKIP (not affected)
# ✗ mobile: SKIP (not affected)
# This is "affected" computation - critical for CI speed in monorepos
npx nx affected:test # Only test affected projects
npx nx affected:build # Only build affected projects
npx nx affected:lint # Only lint affected projects
# Result: CI stays fast even with 50+ projects in one repoQuick Quiz
Tip
Tip
Practice Monorepos vs Polyrepos in small, isolated examples before integrating into larger projects. Breaking concepts into small experiments builds genuine understanding faster than reading alone.
Choose based on team size, release cadence, and deployment model
Practice Task
Note
Practice Task - (1) Write a working example of Monorepos vs Polyrepos from scratch without looking at notes. (2) Modify it to handle an edge case (empty input, null value, or error state). (3) Share your solution in the Priygop community for feedback.
Common Mistake
Warning
A common mistake with Monorepos vs Polyrepos is skipping edge case testing - empty inputs, null values, and unexpected data types. Always validate boundary conditions to write robust, production-ready devops code.
Key Takeaways
- As organizations grow, how you organize your code repositories becomes critical.
- Monorepo: All projects in one repository. Used by Google (2 billion lines!), Facebook, Twitter
- Polyrepo: Each service/project has its own repository. Used by Amazon, Netflix (older)
- Monorepo advantages: atomic cross-service commits, shared tooling, easy code sharing, single CI config