Microservices Fundamentals: When and Why
Microservices architecture has become the default recommendation for scaling applications, but it introduces complexity that monoliths simply don’t have. This lesson gives you the honest picture: when microservices genuinely solve problems, when they create more than they solve, and the critical decisions you need to get right before writing a single line of code.
Watch: Video Walkthrough
Key Concepts
- Monolith vs Microservices: Real tradeoffs in complexity, deployment, and team autonomy
- Domain Boundaries: Using Domain-Driven Design to identify service boundaries
- Communication Patterns: Synchronous (REST, gRPC) vs asynchronous (events, message queues)
- Data Ownership: Each service owns its data — why this matters and how to enforce it
Hands-On Exercise
Task: Take an existing monolithic application (or a hypothetical e-commerce app) and identify 4-5 natural service boundaries using Domain-Driven Design bounded contexts. Document the data each service would own and how they would communicate.
Pro Tips
Start with a monolith. Seriously. Build your application as a well-structured monolith with clear module boundaries, then extract services only when you have a concrete reason — scaling, team independence, or deployment frequency. Premature decomposition is the number one cause of microservice project failure.