jacek kuczyński

perfect developer for your project

business web applications data-heavy applications for real operations: internal platforms, customer portals, dashboards and integrations with the systems you already run.
scalable cloud architecture systems designed for growth: service boundaries, caching, queues, observability and cost control.
CI/CD reproducible builds, preview environments, migrations, staged rollouts and infrastructure as code.
sophisticated AI pipelines production LLM systems: retrieval-augmented generation, agents and tool use, MCP servers, evaluation and guardrails.
from zero to production greenfield builds and rescues, owned end to end: from an empty repository to a monitored, maintainable system.

web application engineer and software architect, based in Poland, working in English and Polish.

languages: TypeScript, JavaScript, Python, Go
frontend: React, Next.js, Vue, Svelte, Astro, Vite, Tailwind CSS
backend: Node.js, Fastify, NestJS, tRPC, GraphQL
data: PostgreSQL, MongoDB, Redis, Elasticsearch, vector databases, Prisma
cloud: AWS, Google Cloud, Vercel, Cloudflare, Docker, Kubernetes, Terraform
delivery: GitHub Actions, Playwright, web performance, accessibility, security
AI: LLM applications, retrieval-augmented generation

agentic engineering: software built with AI agents and for them, from a single coding session to agents that run for days.

coding agents: Claude Code, Codex, Cursor, subagents, parallel sessions in git worktrees
harnesses: custom DeepSeek harness, Claude Agent SDK, tool calling, structured output
models: OpenRouter, local models with Ollama, vLLM and llama.cpp
agents: Hermes agents, long-running agents, multi-agent orchestration, background and scheduled agents
context: Model Context Protocol servers, agent skills, context engineering, persistent memory
content: AI-generated content: copy, images and video, reviewed before publishing
reliability: evals, guardrails, human-in-the-loop approvals, sandboxing, observability, cost control

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