Qwen 27B runs 24hr unattended on one RTX5090, builds full Postgres-SpringBoot-React spreadsheet app
anglepoiselife · reddit · 2026-09-23
A developer demonstrates a custom harness driving Qwen 3.8 27B fully unattended for 24 hours on a single RTX5090 (32GB VRAM, 32k context), producing a working spreadsheet SaaS app: login/registration, workbook/sheet CRUD, cell text/number/formula entry, and auto-save, on Spring Boot + Postgres with a React frontend — 50+ source files passing end-to-end tests. The LLM's only internet access was installing software on a bare Ubuntu VM; total cost: a sub-$4000 machine and under $10 of electricity.
The harness provides goal hierarchies, context compression, memory and facts, file manipulation/search/edit tools, Linux VM shell access, and browser automation. Citing papers like CLI-Tool-Bench (where unconstrained frontier models thrash on simple CLI tasks), the author argues a smart harness matters more than a frontier model. Code and logs are open-sourced in the Self-Directed-Agent repo, with more log snippets offered on request.
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