Microservices Architecture

Microservices is the architectural pattern for building large-scale systems as independent services that communicate via APIs, each with its own database, deployment pipeline, and team ownership. Unlike monolithic applications (one codebase, one database, deployed together), microservices decompose the system along business domains: a payment service, inventory service, order service, each running separately, scaling independently, and deployable without coordination. Netflix pioneered the pattern in 2009 when a single shared database became a bottleneck; today, Uber, Amazon, and Meta run 500+ interdependent microservices. The trade-off is clear: operational complexity increases dramatically (distributed debugging, network failures, data consistency), but you gain independent scaling, team autonomy, and technology flexibility. Microservices is not about the size of the service (common myth: "should be <100 lines"). It's about bounded contexts (Domain-Driven Design) and organizational alignment: one service per team, one team per service, different scaling and deployment schedules.