HebbiaAI·Software Engineer·Technical Phone Screen
Apr 2026
HebbiaAI software engineering interview that went straight into a meaty coding problem. It was a follow-up to standard Tic-Tac-Toe but with a lot more moving parts, and the design discussion around data layout took up more time than I expected.
- Implement Ultimate Tic-Tac-Toe on a 9x9 grid structured as a 3x3 arrangement of 3x3 sub-boards. A move is represented as a tuple of sub-board coordinates, cell coordinates, and the player. A player claims a sub-board by getting three in a row within it, and the overall winner is whoever claims three sub-boards in a row on the outer grid. Discuss your data layout and how you'd detect wins incrementally at both levels.
“I started with the inner board logic since it's basically just regular TTT, but the nesting tripped me up more than I'd like to admit.”