✨ This talk was recorded at Lambda Days in June 2024. If you're curious about our upcoming event, check https://lambdadays.org ✨ Algebraic Data Types are a very simple, yet very powerful tool to use when designing systems. Most developers are familiar with them, or subsets of what we call ADTs, even if they are not aware of them - enumerations, for example, or records. The purpose of this talk is to clarify what ADTs are, what properties they have and how these properties can be used to express strong invariants at the data level - such as making illegal states or state transitions impossible to represent. It also explores the generalised form of ADTs - GADTs - and attempts to lift some of the confusion that surrounds them. We will also (lightly) tackle the theory behind them and try to understand where the “algebraic” part of the name comes from. Let's keep in touch! Follow us on: 💥BlueSky: https://bsky.app/profile/lambdadays.bsky.social 💥LinkedIn: https://www.linkedin.com/company/lambda-days 💥Facebook: https://www.facebook.com/lambdadays 💥Mastodon: https://genserver.social/codesync 💥Twitter: https://twitter.com/LambdaDays