Cartographer
Drops you into an unfamiliar repo and draws the three paths a request can take through it. Built for Pair Programmer's Apprentice — use lumen forge to build a tool for developers who are new to a codebase. Call-graph tracing and the interactive path diagram. The interface is deliberately narrow: one path, done properly, rather than a broad surface that half-works at the deadline.
Gallery
Screens
Cartographer — main view
Cartographer — result state
On the clock
What shipped, what didn't
Completed in time
Call-graph tracing and the interactive path diagram.
Unfinished / faked
TypeScript and Python only. Dynamic dispatch confuses it.
Obstacles
Lost four minutes to an auth redirect loop that turned out to be a trailing slash.
Lessons learned
Scope down before the timer starts, not at minute 20 when you're already committed.
Process
Prompting approach
Started from a single system prompt describing the user and their constraint, then iterated with the assistant on the Cartographer data model before writing any interface code. Full prompt log is in the repository under /prompts.
Fairness
Disclosures
Declared by the builder at submission time, visible to judges before scoring.
Judging
Public feedback
Judges' private notes stay private — this is what they chose to say publicly.
Elena Voss
VP of Engineering, Harbor Compute
Strongest technical work of the day. The architecture choices are defensible at this time budget, and the demo held up under a real input.
Marcus Bell
Founder, Bellwether Studio
Genuinely useful. I would install this. The limitations section is honest, which makes me trust the rest of the submission more.
Hana Kobayashi
Principal Research Engineer, Independent
The scope discipline here is the whole story. One path, finished, demoed without a stumble. That is what a 30-minute build should look like.
Discussion
2 comments
The path diagram is the best thing I've seen in three seasons. How much of the call-graph work was the model versus static analysis?
Mostly static analysis — the model only names the paths and writes the summaries. That split is why it finished. Doing the traversal with the model would have blown the budget by minute 10.