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MonolithvsMicroservices
What is the difference between a monolith and microservices?
Updated 2 min read7 differences
In short
A monolith is one app deployed as a single unit, simple to build and run, while microservices split it into small services that deploy and scale independently.
Monolith
A monolith is a software application built and deployed as a single unit, where all features share one codebase, one process, and usually one database.
Read the page on MonolithMicroservices
Microservices are an architectural style where an application is split into small, independently deployable services that communicate over a network.
Read the page on MicroservicesMonolith and Microservices compared
| Aspect | Monolith | Microservices |
|---|---|---|
| Structure | One codebase and one deployable unit | Many small services, each deployed on its own |
| Deployment | The whole application ships at once | Each service ships independently |
| Scaling | Scale the entire app by running more copies | Scale only the services that need it |
| Communication | In-process function calls | Network calls over HTTP, gRPC or messaging |
| Data | Usually one shared database | Often a separate database per service |
| Operational complexity | Low: one app to build, monitor and debug | High: service discovery, tracing, retries and many pipelines |
| Best for | Small teams, new products and simple domains | Large organizations with many teams and well-understood domains |
The difference, explained
A monolith is an application whose features, such as users, orders and payments, live in one codebase and are deployed together as a single unit. A microservices architecture splits those features into separate services, each with its own codebase, often its own database and its own deployments, communicating over the network through APIs or messages.
The difference is where the boundaries are enforced. In a monolith, modules call each other as ordinary functions, so development, testing and debugging are simple, but one change means redeploying the whole app and all parts scale together. Microservices let teams release and scale each service independently, at the cost of network calls that can fail, data spread across services and much more infrastructure to run.
Many successful systems start as a monolith and extract services only when a clear need appears, such as one part needing to scale differently or many teams getting in each other's way. A middle ground, the modular monolith, keeps one deployment but enforces strict internal boundaries, which makes a later split easier.
A common misconception is that microservices are automatically more modern or scalable. A monolith can scale horizontally by running many copies behind a load balancer, and splitting a system with unclear boundaries often produces a distributed monolith: all the complexity of microservices with none of the independence.
Which one should you use?
Choose Monolith when…
- Your team is small or the product is still finding its shape.
- You want the simplest path to building, testing and deploying.
- The boundaries between parts of the domain are not yet clear.
Choose Microservices when…
- Many teams need to release independently without blocking each other.
- Parts of the system have very different scaling or reliability needs.
- You have the tooling and experience to run distributed systems.
Readers ask
Are microservices better than a monolith?
Neither is better in general. Microservices help large organizations scale teams and components independently, while a monolith is simpler and faster to build for small teams and early products.
What is a modular monolith?
A modular monolith is a single deployable application divided into well-separated modules with clear interfaces, giving much of the structure of microservices without the network and operational overhead.
When should you move from a monolith to microservices?
When a specific pain appears, such as teams blocking each other's releases or one component needing to scale on its own. Many teams migrate gradually, extracting one service at a time with the strangler fig pattern.