Microservices

Microservices is an architectural approach where a software application is built as a collection of small, independent services, each responsible for a specific function. Instead of building one large application (a "monolith"), you build many smaller ones that communicate with each other via APIs.

Think of it like a team of specialists versus one generalist. A monolithic application is like one person doing everything — if they're sick, everything stops. A microservices application is like a team where each person handles one area — if one is unavailable, the rest keep working.

Monolith vs microservices

Monolith: All code is in one application. Simpler to build initially, but harder to maintain and scale as it grows. A change in one area can break something in another.

Microservices: Each feature runs as its own small service. More complex to set up, but each service can be developed, deployed, and scaled independently.

When microservices make sense

Microservices are not always the right choice. They add complexity, so they're best suited for:

• Large, complex applications: Where different features have different scaling needs (e.g. your search engine needs 10x more resources than your user profile service).
• Large development teams: Where multiple teams need to work on different features simultaneously without stepping on each other.
• High availability requirements: Where you need some parts of the system to keep working even if other parts fail.

When to stick with a monolith

For most startups and SMEs building their first product, a monolith is the right starting point. It's simpler, faster to build, and easier to reason about. You can always refactor into microservices later when the complexity justifies it.

The key lesson: don't over-engineer. Start simple and add complexity only when you have a clear, specific reason for it.