What is the importance of database per service in microservices, and what are the challenges?

Short answer: Importance: Decoupling: Each microservice manages its own data, avoiding shared database bottlenecks and promoting service independence.

Explain a bit more

Scalability: Independent databases allow microservices to scale individually based on load. Flexibility: Services can choose different types of databases (SQL, NoSQL) based on their needs (e.g., relational data for one service, document store for another). Autonomy: Microservices can evolve independently without impacting others, as database changes in one service don’t affect others. Challenges: Data Consistency: Ensuring consistency across distributed databases is complex. Eventual consistency and patterns like Sagas need to be used. Data Duplication: Some data might need to be duplicated across services, which can lead to synchronization challenges. Complexity: Managing multiple databases increases operational complexity, such as database migrations and monitoring.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.