ALT Infrastructure: how exe.dev let us scale exe.dev made it easy to work with named Linux machines, plain SSH, Docker and systemd. Its credential integration kept our gateway key off every worker, and in-place resizing gave us more room on the same machines. Together, those choices let us run a matrix of 27,528 attempts across 16 machines with tools we already knew. Scheduling, recovery and grading logic is ours. We are grateful to exe.dev for giving that work a home we could understand, inspect and adapt as the run grew.
ALT Shelley's approach to compaction is to insert a "nudge" message from the harness at about 200k tokens and to give the model a compaction tool that lets it (a) truncate specific tool outputs and (b) "squish" together sections of history into smaller, rewritten segments (which will then have pointers to the originals). 200k seems like the sweet spot for current frontier models, but we've left the exact number configurable.
