ADR 001: Monorepo vs Standalone Repositories
Decision to adopt a monorepo architecture using Turborepo for better code reuse, unified tooling, and simplified dependency management across multiple frontend and backend applications.
Context
The project involves multiple front-end applications and backend services that share UI components, TypeScript types, and development tooling.
Managing these pieces in separate repositories makes synchronization harder and slows down iteration.
We need an architecture that:
- Promotes code reuse across UI and backend apps.
- Provides shared tooling and consistent standards (linting, formatting, build scripts).
- Simplifies dependency management and CI/CD pipelines.
- Keeps developer experience consistent across the codebase.
Considered Options
Option A – Monorepo (Turborepo)
All applications and packages coexist in one repository (apps/*, packages/*), orchestrated by Turborepo.
Pros
- Shared UI components, types, and config across apps.
- Unified tooling and faster CI/CD via Turborepo caching.
- Easier developer onboarding and dependency upgrades.
- Consistent standards enforced project-wide.
Cons
- Slightly higher repo complexity and workspace management overhead.
- Requires clear ownership boundaries to avoid tight coupling.
Option B – Standalone Repositories
Each app or service lives in its own repo, communicating via published packages or APIs.
Pros
- Clean separation of concerns and clearer version boundaries.
- Easier for teams to work independently with isolated pipelines.
Cons
- Harder to keep shared dependencies synchronized.
- Requires multiple CI/CD setups.
- Repeated tooling configuration and code duplication.
Decision
Adopt a Monorepo architecture using Turborepo to orchestrate builds and caching.
Shared components, utilities, and standards will live under packages/, while each app resides under apps/.
TLDR: Comparison Table
| Feature | Monorepo ✅ (Turborepo) | Standalone Repos |
|---|---|---|
| Code reuse | ✅ Shared components/types | ❌ Requires publishing |
| Unified tooling | ✅ Consistent standards | ❌ Multiple configs |
| CI/CD speed | ✅ Turborepo caching | ⚠️ Separate pipelines |
| Dependency sync | ✅ Automatic | ❌ Manual coordination |
| Developer onboarding | ✅ Single repo | ⚠️ Multiple repos |
| Complexity | ⚠️ Higher repo complexity | ✅ Simpler per repo |
| Team independence | ⚠️ Requires coordination | ✅ Independent work |
Main reasons:
- Enables code reuse across UI and backend apps through shared components and types
- Unified tooling and consistent standards across all projects
- Faster CI/CD via Turborepo caching
- Simplified dependency management and easier developer onboarding
Architecture Decisions
Architecture Decision Records (ADRs) documenting key technical decisions for the monorepo.
ADR 002: Backend API Framework & Runtime
Decision to use Node.js LTS runtime with Fastify framework for portability, performance, LTS support, flexibility, and ability to migrate from Vercel to Google Cloud/AWS for production security.