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Roomba Wars

A multiplayer browser game that turns a simple Roomba interview prompt into a realtime 3D arena with procedural terrain, enemies, and benchmark tooling.

A Roomba cleans a grid of dirt tiles in the Infinite Dirt Arena, with live standings in the corner.

The outcome

Reimagined an interview exercise as a multiplayer game prototype with realtime simulation, persistent scoring, and benchmark tooling to test rendering limits at higher player counts.

Roomba Wars takes a very small interview prompt and pushes it into something much closer to a real product and systems exercise.

Roomba Wars screenshot one

Roomba Wars screenshot two

What it includes

  • Multiplayer gameplay in a shared browser arena
  • An infinite procedural dirt field instead of a fixed board
  • Custom player names and Roomba colors
  • Dirt-clearing rules that change where movement is possible
  • Regrowth timing that keeps the arena shifting
  • Dust bunny enemies that create pressure and combat moments
  • Persistent leaderboard tracking best runs
  • A benchmark arena for testing higher player-count rendering behavior

Why I built it

The original interview challenge was about controlling a Roomba on a grid.

After the interview, I wanted to see what would happen if I treated that core idea like the start of a real game instead of the end of a coding prompt. That meant adding realtime multiplayer, a stronger visual layer, and enough gameplay systems to make movement, territory, and score all matter.

Benchmarking became part of that rework too.

One of the scale questions raised in the interview was what happens when the board gets dramatically larger. The benchmark arena is not a perfect stand-in for live websocket traffic, but it gives me a practical way to test rendering constraints and player-count pressure without hand-waving the performance problem away.

Try a piece of this game

Queue a few commands. Navigate the room. Learn why a tiny robot still needs a good plan.

Program a Roomba →

The story behind the build

Article · 2026-03-07

When AI in an interview fails you

I used AI heavily in a technical interview, felt great about the build, and still got rejected because the team could not gauge enough of my understanding.

Read more →

Postmortem · 2026-03-07

Roomba Wars: a working answer is only part of the story

A recap of an AI-assisted interview, the game built afterward, and the lesson about making engineering judgment visible.

Read more →

Build log · 2026-03-08

Week 3: Roomba Wars

Turned a Roomba interview prompt into a multiplayer browser game with realtime systems, 3D rendering, and benchmark tooling.

Read more →

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