I see it all the time: developers jumping straight into a complex microservices architecture for a brand-new startup idea. They spend weeks setting up Kubernetes clusters, service meshes, and distributed tracing, all to support an application that currently has zero concurrent users. This is a classic case of premature optimization. If you haven't even found product-market fit yet, you shouldn't be worrying about horizontal scaling across twenty different services; you should be worrying about how fast you can ship a feature.
The most scalable architecture for a new web app is almost always a well-structured, modular monolith. By keeping your business logic within a single deployment unit, you eliminate the massive overhead of network latency, distributed transactions, and the "distributed monolith" nightmare. A modular monolith allows you to maintain clean boundaries between domains, making it significantly easier to split off specific components into independent services later when—and only when—you actually hit a scaling bottleneck.
Scalability is a technical problem, but premature complexity is a business problem. Every minute you spend managing infrastructure instead of writing core logic is a minute stolen from your users. Build for your current load, but architect for future separation. Don't build a distributed system just because it's trendy; build a system that allows you to survive your own success.
