I built a debugger two people can watch at the same time

I have lost count of the debugging sessions that went like this. I share my screen, I run the code, and I narrate what it is doing line by line while the other person nods at a video feed. They cannot pause it. They cannot rewind it. They cannot point at a variable and ask what it held two steps ago.

So I started building Trace. The short version is Figma, but for debugging. Two people join the same run, watch the same code execute live, and scrub back through it on a timeline when something looks wrong.

I gave it four days before my exams forced a pause. Here is what actually shipped.

Day 1: the tracer

A Python tracer built on sys.settrace, a Pydantic trace schema to keep every step honest, and a Next.js scaffold to show it in. Ten commits, 22 of 22 backend tests green.…