Repowise scores donnemartin/system-design-primer at 9.4 out of 10 for code health, which reads as excellent, alongside maintainability 8.9 and static performance 10.0 on the same scale. There are 9 open findings across the three pillars, and the lowest-scoring file is call_center.py at 8.7. Scores are computed from complexity, duplication, churn and git fix history, not from a linter.