Codility Developer Training vs. CodeSignal

Codility Developer Training is the free practice platform Codility runs for individual developers. Work through programming lessons, timed challenges, and exercises across common languages, algorithms, and data structures, with immediate feedback on whether a solution is correct and how it performs. Developers use it to sharpen fundamentals and prepare for technical interviews, at their own pace. This is a separate offering from the Codility assessment platform that organizations buy.

CodeSignal is the AI-native skills assessment and intelligence platform that shows you who can actually do the job, not just who interviews well. Whether you're making your first hire or your thousandth, our platform brings together skills assessments, work simulations, AI Interviewers, and live technical interviews, giving every candidate a realistic way to show what they can do. Cosmo, our built-in AI assistant, gets you hiring in minutes. Each assessment and interview results in a detailed skills report, giving you the proof behind every hiring decision.