Patryk Łaciak

Full-stack Developer | React, TypeScript & React Native | 3D Visualization

Profile

Full-stack developer specializing in React and TypeScript. I build browser-based 3D tools, shared UI components and backend integrations. Alongside client work, I develop my own web and React Native products.

Experience

Full-stack Developer — Selleo

06.2022 — now

Develop React and TypeScript applications for clients in engineering software, education, scientific modeling and online brand protection.
Responsible for frontend implementation: complex data views, interactive visualizations and reusable UI components.
Contribute backend features, API integrations and automated frontend tests.

Frontend Web Developer, React & PHP — Twójpomysł.it

02.2020 — 01.2023

Contract / Freelance · Built and maintained client websites and web apps in React, PHP and WordPress alongside technical school.

Web Development Tutor

12.2020 — 05.2022

Tutored students in building websites and web applications.

React Developer Intern — Selleo

06.2021 — 08.2021

Worked on frontend development with React and TypeScript.

Frontend Web Developer — Grupa EVADA

03.2021 — 05.2021

Contract / Freelance · Built client websites.

Frontend Web Developer — Qualinet

02.2021 — 03.2021

Contract / Freelance · Built client websites.

Selected projects

Engineering Applications — 3D Analysis

12.2024 — now

Commercial work · Client confidential

Browser-based engineering applications for interactive 3D visualization and data analysis.

Build frontend interfaces, interactive 3D tools and reusable UI components; occasional backend contributions.
Built a browser-based 3D viewer and worked on its performance.
Connected 3D visualization with interactive charts and analysis interfaces.
Developed reusable UI components.

React · TypeScript · Tailwind CSS · D3 · Vitest · Playwright

Scientific Modeling Platform

01.2023 — 09.2023

Commercial work · NDA

Developed and maintained an existing modeling editor, including editing interactions and change history with undo/redo.

React · TypeScript · Redux

Online Brand Protection Platform

07.2022 — 10.2024

Commercial work · Anonymized

Built frontend workflows for monitoring configuration and listing review, with authentication, API integrations, filtering, sorting and search.
Developed UI components in Storybook and automated end-to-end tests.

React · TypeScript · React Query · Cypress · Storybook

EdTech Platform — AI-assisted Assessment

10.2024 — 03.2025

Commercial work · Anonymized

AI-assisted assessment within an educational platform.

Delivered it independently: interface design, frontend, backend, AI integration, QA.
Integrated AI-assisted assessment into the existing platform.
Built the teacher interface to review and correct AI results before approval.

React · TypeScript · AI integration

Workout Tracking & Coaching Platform

05.2025 — now

Personal product

Workout tracker with trainer–trainee management, used by me and a few gym users.

Own product decisions, UI design, React web/PWA and backend development.
Turn imported spreadsheet plans into structured workouts with AI; built plan composition/refinement, training analytics and trainer supervision.
Develop the React Native app (since 05.2026). Web/PWA is live; iOS in TestFlight.

React · TypeScript · React Native · Expo · Tailwind CSS · NativeWind · TanStack Query · Zustand · Elysia.js · Bun · PostgreSQL · Drizzle · Mistral

Rental Management App

01.2026 — now

Personal product · Built with my brother

React Native app for rental management, currently in testing; not yet publicly deployed, demo available during interviews.

Designed and built owner/tenant mobile interfaces: properties, leases, invitations, history, archives, export, chat, notifications and calendar; occasional backend/AWS changes.

React Native · Expo · TypeScript · NativeWind · TanStack Query · Zustand

Skills

Frontend: React · TypeScript · JavaScript · Tailwind CSS · Vite
Mobile: React Native · Expo · NativeWind
3D & data viz: VTK · C++/WebAssembly viewer development · Three.js · D3
State & data: TanStack Query · Zustand · Redux · Recoil
Backend: Node.js · Bun · Elysia.js · Fastify · Python/FastAPI · PostgreSQL · Drizzle · AI integrations
Testing, tools: Vitest · Playwright · Cypress · Storybook · Git · Docker · monorepos

Education

IT Technician — TEB Edukacja · Technical secondary school

2018 — 2022

Languages

Polish — Native · English — B2