What defines a microservice architecture?

A microservice architecture is characterized by structuring an application as a collection of loosely coupled services. This approach allows each service to be developed, deployed, and scaled independently while still functioning cohesively within the larger system. Each service typically encapsulates a specific business capability, which enhances modularity and enables teams to work in parallel, often leading to faster development cycles.

In this architecture, services communicate with each other over well-defined APIs, usually through lightweight protocols like HTTP/JSON or messaging queues. This separation allows for flexibility in technology choices, as each service can be developed using different programming languages, frameworks, and databases based on the specific needs of that service. Consequently, it not only promotes an agile and scalable development process but also makes it easier to maintain and update individual components without affecting the entire application.

In contrast, the other options describe characteristics that do not align with microservices, such as monolithic designs which integrate all components tightly, reliance on outdated technologies, and the misconception that all services must be deployed simultaneously. These approaches can hinder scalability, agility, and maintainability, which are central tenets of microservice architecture.