## Notes
[[Lichess]] is an open-source chess application that handles a large number of users on a variety of devices. It's quite amazing what a team of 2 developers have done. [1 Lichess Developer - YouTube](https://www.youtube.com/watch?v=7VSVfQcaxFY) talks about [[Thibault Duplessis]] and how he created a massive free chess web application by himself, his journey, and his philosophy.
## Main Takeaways
- He kept the UI minimal and focused on user experience
- He used the smallest libraries and took away dependencies that would otherwise slow down everything
- *Lichess* operates primarily as a monolith with only a handful of microservices
- He outsourced the mobile app work to Flutter
- Used the right tool for the right job
- Backend is primarily written in Scala
- Used Rust for OS-level operations
- Used Snabbdom because of its DOM handling
- Optimized based on observability--changes were driven by current needs instead of market hype
- Uses [[MongoDB]] but not critical and could work on [[PostgreSQL]]
- [[Redis]] provides a layer of abstraction so that *Lichess* can deploy updates with minimal disruptions