Microservices vs Monolith: Which Architecture Fits

No. A well-built monolith can scale horizontally to handle very large traffic by running multiple instances behind a load balancer. Microservices help when different parts of the system need to scale independently or when a single codebase becomes an organizational bottleneck. Scalability is about matching resources to demand, and both architectures can do that; they just do it differently.

There is no exact number, but the value of microservices grows as you add teams that need to deploy independently. As a general guide, a single team is almost always better off with a monolith, while the case strengthens once you have multiple teams stepping on each other in one codebase. The trigger is organizational friction and differing scaling needs, not headcount alone.

Yes, and for most products that is the recommended path. Starting with a modular monolith lets you ship quickly, learn your domain, and discover where real boundaries lie. If you keep the internal modules clean, extracting services later becomes far easier than trying to guess boundaries on day one.

A modular monolith is a single deployable application organized into well-separated internal modules with clear boundaries and minimal coupling. It gives you much of the code organization and maintainability of microservices without the network, deployment, and data complexity of a distributed system. For many teams it is the pragmatic middle ground and a strong stepping stone toward selective service extraction.

Usually yes, especially in infrastructure and operational effort. You run more services, more pipelines, and more monitoring, and you typically need dedicated DevOps or platform capacity. Those costs can be justified at scale, but they are real and ongoing, so they belong in the decision from the start rather than as a surprise later.