Monolith to Microservices Template

Three signals indicate the need: (1) multiple teams are blocked by each other during deployments, (2) scaling individual features is impossible without scaling the entire application, and (3) test suites have grown so large that feedback loops are measured in hours. If your monolith serves a single team and deploys quickly, decomposition adds complexity without delivering benefits. Monoliths are not inherently bad. They become problematic when organizational and operational scaling demands exceed what a single deployable unit can support.

Extract only as many services as you have teams to own them. Every service needs a team that owns its deployment, monitoring, and on-call rotation. A common mistake is extracting 20 services for a 3-team organization, resulting in services that nobody owns and nobody monitors. Start with one service per team as a maximum, then add services only when a team demonstrates it can operate its existing services well.

Avoid distributed transactions. Instead, use the saga pattern: each service completes its local transaction and publishes an event. Downstream services react to the event and execute their local transactions. If any step fails, compensating transactions undo previous steps. This requires designing for eventual consistency, which means your UI and business logic must tolerate brief periods where data across services is not perfectly synchronized.

Starting too many extractions in parallel. Teams get excited, identify 8 service candidates, and start building all of them simultaneously. The result is 8 half-finished services, a monolith with 8 new integration points, and an operations team overwhelmed by the complexity. Sequential extraction with thorough validation between each step is consistently more effective.

Not necessarily, but standardize unless there is a strong reason not to. Polyglot microservices sound appealing in architecture diagrams but create real operational burden: different build pipelines, different monitoring libraries, different deployment mechanisms, and different debugging tools. Use one or two primary languages and frameworks. Only introduce a different technology when it provides a clear, measurable advantage for a specific service's requirements.