Working with our support team, I often see customers having timeout problems. Typically, their applications will start throwing H12 errors.

The decision to timeout requests quickly wasn't made to avoid having long-running requests on our router, nor to only have fast apps on our platform, but because standard web servers do not handle these types of requests particularly well.

Performance is important, and if we can't measure something, we can't make it fast. Recently, I've had my eye on the ActionDispatch::Static middleware in Rails. This middleware gets put at the front of your stack when you set config.serve_static_assets = true in your Rails app. This middleware has to compare every request that comes in to see if it should render a file from the disk or return the request further up the stack. This post is how I was able to benchmark the middleware and give it a crazy speed boost.

Flow is an important part of software development. The ability to achieve flow during daily work makes software development a uniquely enjoyable profession. Interruptions in your code/test loop make this state harder to achieve. Whether you are running unit tests locally, launching a local webserver, or deploying to Heroku there's always some waiting and some interruption. Every second saved helps you stay in your flow.

We’ve been working on reducing the time it takes to build your code on Heroku. Read through this post for details on the process we used to make builds fast, or check out the end result from the graph below:

Let's take a look at our process in delivering these...