ACCU York [May 2026] - "Would Your Tests Still Pass in İstanbul?"

🕡 Doors open 18:30
📋 Intro and admin 18:50
🗣️ Talk by Sam Cooper (🕖 start at 19:00)
For years, people in and around Turkey have been used to seeing strange errors in popular software: Dropbox files failing to sync, Unity games freezing, Gradle builds crashing for no apparent reason. One security researcher even found a way to break into GitHub accounts using nothing but a Turkish email address.

The connection? A single alphabet character. In this talk, we'll take a hands-on look at some famous examples of the Turkish 'i' bug, including the years-long detective story of how locale-sensitive case conversions kept crashing the Kotlin compiler.

More importantly, we'll look at how you can avoid becoming the bug's next victim. We'll examine the faulty functions that make the bug possible, and see how to spot if your program, language, or library is affected. Then we'll check out the "Turkey Test"—a simple strategy for catching localization bugs before they reach production.

If you write code in any programming language—or if you just like learning about weird software quirks—you'll have fun following the trail of destruction left by this surprising one-letter bug. No prior knowledge required.

🍕 Food will be provided, let us know if you have dietary requirements
🔗 Finish off with Q&A, networking, and 🍻
----
About the speaker: Sam Cooper
Sam Cooper is the author of Kotlin Brain Teasers and Kotlin Coroutine Confidence, both published by the Pragmatic Bookshelf in 2025. His tech writing has also featured in community publications like Kotlin Weekly, Android Weekly, and Software Testing Weekly, and has even hit the top of the Hacker News front page.

Sam spent many years crafting developer-facing APIs and high-throughput backend services in Kotlin at Anaplan, where he was a Principal Engineer and tech lead. Before that, he worked at Amazon Web Services building multiplayer games infrastructure in Java. Sam holds two Master's degrees: one in Computer Science from University College London, and one in Modern Languages from the University of Oxford.

His motto (which he stole from a former boss) is "speed through quality": he believes (with receipts) that "cutting corners" in programming is a myth, and that clean, well-tested code always gets you to your destination faster.
----
ACCU York is an ACCU local group
Follow on Mastodon: https://fosstodon.org/@accu_york
Venue sponsors: Patch
Community sponsors: YorkDevelopers group, WiT York, Ministry of Testing York, Tech York, dotNet York, York Code Dojo, Leeds PHP, York Ruby, NYNE Games Dev Kitchen