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Microservices
Migration & Refactoring
Strangler Application
Grow a new microservice system around your monolith — strangle it piece by piece until nothing's left.
Intent & Description
Real-world Use Case
E-commerce monolith. Strangler starts: proxy sits in front. Search is extracted to Elasticsearch-backed Search Service first — proxy routes /search to it. Then Product Catalog. Then Orders. Over 18 months, monolith is drained and decommissioned.
Source
📌 TL;DR
Strangler Fig = migrate your monolith without rewriting it. One slice at a time, proxy routes the way. Slow, safe, and the only sane way to migrate at scale.
Advantages
- No big bang rewrite — low risk, continuous delivery throughout migration
- Ship new microservices incrementally — value delivered from day one
- Rollback is easy — proxy can route back to monolith if new service has issues
- Teams learn microservice patterns in production, not in a vacuum
Disadvantages
- Proxy/facade must be maintained and scaled throughout migration
- Shared database coupling slows extraction until DBs are separated
- Can take years — requires sustained organizational commitment
- Running two systems in parallel doubles operational complexity during migration