Available for senior IC / tech-lead contracts

Systems thatsurviveproduction.

Fullstack developer with 10 years of end-to-end product delivery — from FinTech banking interfaces at Citi to multi-property infrastructure at scale. Strong in React/Next.js, TypeScript, Node.js and AWS, comfortable owning the whole delivery: architecture, API design, CI/CD and production monitoring. Currently focused on production LLM systems — RAG pipelines with hybrid retrieval, evals and enterprise security (RLS, audit trails).

Role
Senior fullstack
Base
Kraków, PL
Mode
Remote
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10yrs

End-to-end delivery

≤700ms

p95 RAG retrieval

99.9%

Uptime across 200+ properties

<10ms

Webhook enqueue latency

[ 01 ]

How I work

Method

I don’t start with the model.
I start with the problem.

The best AI systems are good systems first. I map responsibility boundaries, data paths and the way quality gets measured before any tool gets picked — then make the database, not a convention, enforce the rules.

See the full stack
  • 01

    RAG you can evaluate

    Hybrid retrieval, reranking, golden test sets and grounded answers — quality is a number, not a feeling.

  • 02

    Backends without magic

    Rust, Tokio and Axum for the hot path; Python and Node where iteration speed wins. Explicit over clever.

  • 03

    Security as a contract

    Row-Level Security, ACLs, signed webhooks and append-only audit logs — enforced by the database, not by convention.

[ 03 ]

Key achievements

Ten years of delivery

Enterprise RAG in production

Built Interim Robots — an enterprise RAG platform for internal procedures: hybrid retrieval (RRF + reranking, p95 ≤ 700 ms), Postgres RLS isolation and an append-only audit log designed for EU AI Act Art. 12.

Edge migration at scale

Architected and delivered a Cloudflare (WAF + CDN) migration for 200+ web properties — 99.9% uptime for a pharmaceutical e-commerce ecosystem handling high-traffic peaks.

Public-sector platform under load

Built and scaled a Django/AWS backend for an EU-funded educational platform serving thousands of concurrent users — designed to absorb load spikes without infrastructure changes.

Streaming, end to end

Developed a PPV video streaming platform (Fightime.tv) from scratch in Rust + Next.js on AWS — ingest pipeline, auth, payment integration and CDN delivery.

Financial analytics SaaS

Engineered VerifyStock.com — real-time data feeds, Stripe billing, Supabase and multi-region AWS deployment.

Need the same, for your system?

Get in touch

Have a system that
has to work?

michal@kezzlock.eu