tl;dr: HackerRank's open-sourced ATS (hiring-agent) produces wildly inconsistent resume scores—the same resume scored anywhere from 66 to 99 across 100 runs, meaning a candidate could fail an 85-point cutoff 65% of the time purely by chance. The author traces this to flawed design: subjective categories like "projects" rely on LLM vibe-checks with no proper rubric, while "experience" gives everyone 25/25 regardless of seniority due to a two-line prompt. With 65% of the score weighted on open source and projects, the tool filters by noise rather than quality.