What is lumen?

Lumen is a lightweight PHP framework for building web applications and APIs quickly. It was designed as a stripped-down, speed-focused sibling to Laravel, one of the most popular PHP frameworks. The main idea is to give developers a clean, simple toolkit for handling common web development tasks, like routing web requests, connecting to databases, managing background queues, and caching data, without the overhead of a larger framework. At a high level, a framework like this provides the foundational plumbing for a web app so a developer doesn't have to build it from scratch. When a user visits a URL, the framework catches that request and directs it to the correct piece of custom code. It provides built-in tools to fetch or save information in a database and return a response to the user. Because it is a "micro-framework," it intentionally leaves out heavier features that larger systems include by default, which allows it to process requests faster and with less memory. The original target audience was developers building things like microservices or APIs, back-end systems that prioritize speed and don't need the full feature set of a large application framework. For example, a startup might have used it to build a fast middleware service that simply takes in data from one app, formats it, and passes it along to another. However, the maintainers no longer recommend starting new projects with it. They note that PHP itself has gotten significantly faster over the years, and a related high-performance tool called Laravel Octane now makes the full Laravel framework fast enough for most use cases. The project remains available and maintained for existing applications, but new builds are directed toward the main Laravel ecosystem.