.NET Tech Lead · Warsaw · available for consulting
My strongest edges are performance optimization and delivering critical work under pressure.
> about
.NET Tech Lead heading developer teams, with experience building and scaling production systems. Currently I'm leading an AI-first rebuild of a large legacy portal — AI is the primary builder, but every module is governed by human-approved test contracts, enforced architecture boundaries, and quality gates that don't move. I believe AI-first only works when the discipline is engineered in, not hoped for.
I'm always curious about what lies beneath the technical surface, but I also consider myself an intuitive person with a natural talent for understanding people and helping them be the most effective, both as individuals and as a team.
Formal background: MSc (Eng) in Computer Science with a specialty in project management, MBA Essentials (LSE), PSM II, PSPO II.
> what I do
01
N+1 query patterns, deadlocks, concurrency and multi-threading problems, memory leaks, critical-path response times. Across .NET, MS SQL Server and PostgreSQL.
02
Setting technical direction, mentoring, unblocking day-to-day work, and owning end-to-end delivery: estimating, milestone planning, scope trade-offs, transparent progress so deadline risks surface early.
03
Test contracts up front, architecture boundaries and quality gates enforced in CI rather than left as guidelines, human-owned final refactor pass — and coaching teams to review AI output critically.
04
Taking over complex or stalled work when it needs to get across the finish line — usually on the critical path, usually under a deadline.
> selected work
2026 — now
Greenfield rebuild where AI is the primary implementer for every module, but no code is written without a human-approved test contract first, and architecture boundaries and quality gates are enforced in CI, not left as guidelines.
.NET 10 · ASP.NET Core · EF Core · PostgreSQL · Kafka · OpenTelemetry · Azure DevOps
2022 — 2026
Core engineer replacing a legacy mainframe calculation system with modern .NET Web API services on Kubernetes. Delivered against a hard deadline after a previous multi-year effort had stalled, avoiding a major annual license renewal cost to the business.
.NET 9 · Kubernetes · MS SQL Server · PostgreSQL · Kafka · REST
performance
Drove the split of one huge database into smaller instances and adjusted the whole system around it — 15× better performance of the whole system for end users. Alongside it: eliminating N+1 query patterns, cutting critical-path response times, resolving deadlocks and concurrency problems.
MS SQL Server · T-SQL · dotTrace · dotMemory · Application Insights · Grafana
> stack
Write to me and tell me what you're dealing with. I answer every message myself.