Meet Allison & Tim
Your AI coaches
Practice coding interviews out loud with real-time voice coaching. Your code actually runs.
Start Part 1 to unlock your next challenge
Analytics: Longest Unique Session Window
Also known as: Longest Substring Without Repeating Characters
This one is the sliding window pattern: grow, shrink, and maintain just enough state to stay linear. Interviewers love it because it reveals your stateful scanning and your edge-case discipline. Once your window update rules are consistent, you get linear time almost for free.
Meet Allison & Tim
Your AI coaches
Practice coding interviews out loud with real-time voice coaching. Your code actually runs.
Desktop required to run this problem
StrongYes runs real code + tests in a desktop editor. Mobile is view-only for now, so you can’t start this here. Sorry about that — email yourself a link and pick it up on your computer.
Start Part 1 to unlock your next challenge
Desktop required
Sorry — mobile can’t run the editor + tests yet. Email yourself a link to continue on desktop.