Modular Monolith and Microservices: Modularity is what truly matters

Modularity is the fundamental principle in software architecture, independent of whether you choose a monolith or microservices. The article explores five implementation strategies ranging from simple modular monoliths (modules as folders) to full microservices, emphasizing that good module separation based on domain understanding should drive architectural decisions, not the other way around. Key insight: start simple with a modular monolith and only increase complexity when justified by specific needs like resource optimization or team scaling. The author advocates for constrained microservices (microliths) that prohibit synchronous inter-service calls during request handling, reducing distributed system complexity while maintaining deployment independence.