Strange Loop

A Frontend Server, Front to Back

For any service, the frontend is the services which depend on it, and the backend is the services it depends upon. In a many-layered service-oriented system, the frontend server is the outermost layer, responsible for handling requests from the outside world. Typically, a frontend server is responsible for universal behavior, including authentication, rate limiting, and traffic prioritization.

The exact behavior will vary from company from company, and so most large software organizations will write one from scratch; Google has "gws", and Twitter has "tfe". Recently, Fitbit built its own. Such a server has to be fast, stable, scalable, extensible, and easy to monitor. However, the entire code base is only 3000 lines of code, making it an ideal platform for exploring the low-level engineering decisions that enable these properties, and the tradeoffs between them.

This talk will explore the implementation of Fitbit's frontend server, covering topics ranging from queueing theory and software design to GC tuning and the Netty library. It is meant to be a deeply practical discussion of topics which are normally only discussed in the abstract.

Zach Tellman

Zach Tellman


Zach Tellman writes a lot of code. Most of it's good. He has released a wide variety of open source libraries, mostly in Clojure. He has given a bunch of talks, some of which are about software and post-modern critical theory, and some of which are ridiculous. He is writing a book titled "Elements of Clojure", which spends a lot of times talking about names and no time talking about cache invalidation. He currently works at Fitbit, where he leads the API Infrastructure team.