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
Time Based Key-Value Store
Each key holds multiple values at different timestamps, and you need the most recent value at or before a given time. Interviewers love it because it reveals your binary search precision—one wrong boundary update can loop forever. The trap is boundary drift. Nail this and temporal queries become second nature.
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.