Krystian Jońca · Full-stack & AI-agents engineer

Full-stack TypeScript engineer with ~4 years of commercial experience (7+ years writing code). I take products from idea to production across the whole stack: React / Vue front-ends, Node / Hono / Effect back-ends, and AI features on the serverless edge. Three of my side-projects are live with real users: a published open-source CLI, a cross-platform poker app (web + iOS + Android), and an AI audiobook SaaS. By day I work on an AI research platform for scientists; on the side I'm writing my engineering thesis on serverless AI agents. I build with agentic workflows day to day: Claude Code, custom agent skills, and MCP.

Experience

Jul 2022 – Present

Full-stack TypeScript Engineer · Tooploox

Full-stack delivery across a sequence of products over nearly four years, front-end to back-end.

AI platform for scientists Apr 2026 – Present · current

Full-stack on an AI-heavy research platform for scientists: a React + Tailwind front end backed by an Effect (TypeScript) API.

React · TypeScript · Tailwind · shadcn/ui · Plate.js · Effect · GraphQL · Postgres

AI onboarding agent Jan – Apr 2026

Full-stack on an AI onboarding agent for a global fashion brand: a React front end with a Python + OpenAI Agents SDK back end.

React · TypeScript · Tailwind · Python · OpenAI Agents SDK

Editorial content platform Sep 2022 – Dec 2025

Owned features end-to-end on a long-running editorial content platform over ~3 years: built the document editor and other core tools, kept large datasets fast and responsive, sped up and stabilized the test suite, prototyped a more secure sign-in flow, and mentored new team members.

Vue 3 · TypeScript · TanStack Query · Pinia · Tailwind · Storybook · Vitest · Playwright · Python · Sentry

Crypto ↔ fiat conversion platform Jul – Sep 2022

Scaffolded and built the platform’s REST API from the ground up for an early-stage startup: authentication, core endpoints, and a PostgreSQL data layer.

NestJS · TypeScript · Redis · PostgreSQL

Selected work

Poker Night

Live · web + iOS/Android

Schedule home-poker games, track scores, and settle up, across web and mobile.

One TypeScript codebase spanning a TanStack Start web app, an Expo (React Native) mobile app and a Hono API, with types inferred end-to-end from route to React hook; real-time over Cloudflare Durable Objects (hibernating WebSockets), AI game recaps and play-style profiles via Workers AI, and multi-channel notifications (WebSocket, email, push).
Greedy settlement algorithm that clears all debts in a small number of payments; Postgres over Hyperdrive with Drizzle, Better Auth, a RevenueCat Pro tier, Pulumi IaC, and ~1,500 tests.

TypeScript · React 19 · TanStack Start · Expo · Hono · Cloudflare Workers / Durable Objects / Hyperdrive / R2 / Queues / Workers AI · Postgres · Drizzle · Pulumi

pokernightapp.com (pokernightapp.com) App Store (apps.apple.com/…/id6760563257) Google Play (play.google.com/…)

Lektorek

Live · AI SaaS

Turn any document into a Polish or English audiobook. Pay per file.

LLM extraction (Gemini 3 Flash) over PDFs, Office docs and scans feeding neural TTS (Azure), stitched to MP3 by Go ffmpeg/libreoffice sidecar containers; orchestrated as a durable Cloudflare Workflows pipeline that samples pages to price each file before checkout.
Strictly layered architecture in Effect (TypeScript), with the dependency rule enforced by a CI test; Stripe checkout + proportional auto-refunds, Better Auth OTP + Turnstile, live progress over Durable Objects, Pulumi IaC, Sentry.

TypeScript · Go · React 19 · TanStack Start · Effect · Cloudflare Workers / Workflows / Durable Objects / Containers / D1 / R2 · Gemini · Azure Speech · Stripe

lektorek.pl (lektorek.pl)

lnai

Open source · npm

One unified .ai/ config, synced to every AI coding tool.

Define AGENTS.md, rules, skills, MCP servers and permissions once in .ai/; export to Claude Code, Cursor, GitHub Copilot, Gemini CLI, Codex, OpenCode & Windsurf via a plugin architecture with per-tool overrides and idempotent, manifest-driven sync (SHA-256 diffing + orphan cleanup).
Published to npm (lnai + @lnai/core) with OIDC trusted publishing; 545 tests (2:1 test-to-code), a knip/audit/lint CI gate, and Astro/Starlight docs.

TypeScript · Turborepo · pnpm · Zod · commander · tsup · Vitest · Astro

lnai.sh (lnai.sh) npm (npmjs.com/package/lnai) GitHub (github.com/KrystianJonca/lnai)

Argus

BEng thesis

A serverless AI agent that monitors new scientific publications for you.

“Code Mode” agent: the LLM writes programs against a typed capability API that run in network-isolated Dynamic Workers, with credentials held host-side; one Durable Object per standing query owns its cursor, cron and chat.
Vectorize-backed RAG ranks papers from arXiv, OpenAlex & Semantic Scholar, with Web Push on new hits; Workers AI + Hyperdrive → Neon (Postgres), provisioned across Pulumi and Wrangler.

TypeScript · Cloudflare Workers / Durable Objects / Vectorize / Workers AI · Code Mode · Hyperdrive · Neon · Pulumi

Warsaw University of Technology

Skills

Languages

TypeScript · JavaScript · Python · Go · SQL

Frontend

React 19 · Vue 3 · TanStack Start / Query / Router · Tailwind · Expo · Storybook

Backend & data

Node.js · Hono · NestJS · Effect · Drizzle · REST / WebSockets · PostgreSQL · SQLite / D1 · Redis · Neon

Cloud & edge

Cloudflare Workers · Durable Objects · Queues · Workflows · R2 / KV · Workers AI · AWS · Pulumi

AI & quality

LLM apps · RAG · “Code Mode” · OpenAI Agents SDK · Gemini · Azure Speech · Vitest · Playwright · CI/CD

Agentic engineering

Claude Code · custom agent skills · MCP servers · AGENTS.md / CLAUDE.md workflows

Education

2022 – 2026 expected Sep 2026

BEng, Applied Computer Science

Warsaw University of Technology (Politechnika Warszawska)

Thesis: Argus (see Selected work). Expected September 2026.

2026 – Planned

MSc, Computer Science with Artificial Intelligence

University of York (online)