Brief highlights
When you design a new product, “monolith or microservices?” is one of the first architectural questions you’ll hit. There’s no universal right answer, only a better fit for your team, stage, and problem.
A monolith is a single application that bundles all core features into one codebase and one deployable unit. Everything lives together: API, business logic, background jobs, web UI, sometimes even admin tools.
Why teams start here?
Simple to reason about -> one project, one deployment pipeline
Easier for small teams -> everyone works in the same place
Debugging is straightforward -> logs and behavior are centralized
Good fit for early-stage products that change fast
The downside shows up as the system grows -> builds get slower and even small changes can require touching unrelated areas of the code.
What are microservices?
Microservices split the system into many small, independent services. Each service owns a narrow set of responsibilities and communicates with others over the network (often via HTTP or messaging).
Why teams move here?
Independent deployment and scaling for each service
Teams can work in parallel with fewer conflicts
Failures can be isolated instead of taking down the whole system
Technology flexibility -> different services can use different stacks
The tradeoff is operational complexity. You now manage many services, network calls, versioning, and data consistency across boundaries.
How to choose for your system
A good rule of thumb is to opt for a well-structured monolith until the pain of staying monolithic is greater than the cost of splitting apart.
Microservices start to make sense when:
-> Different parts of the system scale very differently (for example, read-heavy public APIs vs. internal tools)
-> Multiple teams need to ship independently without stepping on each other
-> Release risk in a single deploy has become unmanageable despite refactoring
Modular monoliths and gradually extract services as boundaries solidify. The key question to keep asking is: Does this architecture make it easier or harder for my team to deliver reliable value quickly?