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#TALK open source success story

The second most popular chess server is free, open source, and maintained by volunteers only. How do we do it?

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Most programmers have side projects. They're usually short lived, but once in a while, one of them gets some traction and amazing things start happening. Started 5 years ago as a real-time web app experiment, is now one of the most popular chess servers and websites around.

Many things have changed, but the core philosophy remains the same: it's free for everyone, there will never be ads, all source code is open sourced under MIT.

We'll discuss the challenges faced during lichess outstanding growth.

How to keep the codebase efficient and maintainable. How to leverage the community energy to solve problems. How to outperform million dollars companies, without raising a cent. How to host more than 5 million new chess games per month, for 183$ of server costs.

This talk will go through several aspects of building a successful web service, from the backend, frontend, architecture, sysadmin, and community management perspectives.

Source code:

Stack: scala, mongodb, elasticsearch, nginx, mithril.js, websocket.

Fancy representation of lichess real-time network:

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Thibault Duplessis

Functionnal programmer and open source enthusiast, I'm a developer at and the founder of

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