I build backend systems that stay reliable when traffic gets ugly. My work spans financial infrastructure, large-scale legacy migrations, and event-driven architectures supporting hundreds of thousands of active users. I care about clean code, sensible abstractions, and making complex systems boring to operate.
- Fintech & Transactional Systems — Building dependable financial modules (savings, wallets, treasury bills, KYC, virtual accounts) on event-driven architectures where correctness and auditability matter more than cleverness.
- Distributed Systems at Scale — Microservices, message queues, and caching layers designed to keep latency low and failure modes predictable.
- Legacy Modernization — Untangling and upgrading large PHP/Symfony codebases without breaking production. I've migrated 200k+ lines of legacy code and lived to tell the tale.
- Performance Engineering — Profiling, tracing, and optimizing API response times, database queries, and frontend load times where it actually moves the needle.
Backend & Languages
Data, Caching & Messaging
Cloud & Infrastructure
Frontend (when the work calls for it)
- Ladda — Built core financial modules (Savings, Commercial Papers, Wallets, Treasury Bills, KYC, Virtual Accounts) that lifted processing efficiency by 30% and helped drive team delivery velocity up by 50%.
- commercetools — Led the Symfony 4 → 5 upgrade and dependency overhaul solo, cutting API response times by 30%. Optimized the page builder for 55% faster loads across 1000+ businesses, and introduced OpenTelemetry tracing that halved debugging time.
- GENEO Software — Migrated 200,000+ lines of PHP from 5.6 to 8.0, yielding a 40% performance improvement and a 70% reduction in technical debt.
- HotelsNG — Maintained and scaled a platform serving 300,000+ active users, leading a team of 5+ engineers across 50+ deployments.
- AREA 17 (about.nike.com) — Contributed to full-stack improvements that lifted user engagement by 15% and reduced bounce rate by 8%.
"I build productive software, not proof-of-concepts."
- LinkedIn: linkedin.com/in/ahless
- GitHub: github.com/iamahless