01
- Backend and payments
- .NET APIs and the partner integrations behind them: REST, SOAP and SFTP transports, mutual TLS, request signing, idempotency, reconciliation. About forty partners so far. I also moved identity to Keycloak and secrets to OpenBao, so nothing sensitive lives in code.
02
- SQL Server
- Deadlock capture with Extended Events, Read Committed Snapshot Isolation, redesigning the transactions that collide, and the procedure and index work behind a P95 that went from 1.56 s to 512 ms.
03
- Mobile
- The company's React Native app, written alone: 35 screens, four languages, OIDC with PKCE, biometric unlock, one pentest remediation cycle, live in both stores.
04
- Infrastructure and security
- The Jenkins shared library that deploys everything, Prometheus and Grafana, OpenTelemetry, a Wazuh SIEM, Cloudflare WAF and failover, and an Azure bill cut by 59% without dropping a workload.
05
- Agentic coding
- I have worked with coding agents every day since 2024. For the team that turned into a shared configuration for Claude Code, Codex and Cursor, a PR-review action, a hook that refuses commits without tests, an AI usage policy, and a monthly report to management on what it actually saves.
06
- Legacy modernization
- ASP.NET WebForms moved off inline SQL onto stored procedures one page at a time, and a .NET 10 plus React path written up so the next person can repeat it. No rewrite, no big bang.