What is the difference between brownfield and greenfield development?

Question

Accepted Answer

**Greenfield** — new project, no legacy. **Brownfield** — existing system, modernization.

**Greenfield:**
- New project from scratch.
- No constraints from legacy.
- Full freedom in design.
- New technology choices.
- Higher risk, higher reward.

```
Greenfield:
- New startup product
- New mobile app
- New microservice
```

**Brownfield:**
- Existing system modification.
- Legacy constraints.
- Must understand existing code.
- Incremental improvements.
- Lower risk, incremental value.

```
Brownfield:
- Migrating monolith to microservices
- Adding features to existing app
- Refactoring legacy code
```

**Key differences:**
- **Greenfield** — new.
- **Brownfield** — existing.
- **Greenfield** — more freedom.
- **Brownfield** — more constraints.

Systems Analyst: What is the difference between brownfield and greenfield development?