This repository contains short, sanitized case studies of real production work focused on:
- Performance (SQL/query design, indexing, caching)
- Reliability (deploy safety, rollback strategies, operational guardrails)
- Security (tokenization, access controls, data protection)
- Payments (Stripe, idempotency, usage-based billing)
Notes: Company/product names, table names, and sensitive details are redacted. Numbers reflect real outcomes.
| Case | Outcome | Topics |
|---|---|---|
| SQL performance: 40s → 3s | 13x latency reduction | MySQL, EXPLAIN, query design |