Jakub Gontarek

Fullstack Engineer

REACT · NEXT.JSNODE.JS · NESTJSJAVA · SPRING BOOTPOSTGRESQL · DOCKER · CI/CDREACT · NEXT.JS
I take projects from requirements to production - architecture, API, data model, UI, tests, deployment.
TypeScript and Java. React and Next.js on the frontend, NestJS and Spring Boot on the backend, with PostgreSQL, Docker, CI/CD and self-hosted infrastructure.
See my workGet in touch
Jakub Gontarek at work

Build. Ship. Own it.

Three years of shipping software that people use every day - solo, with internal teams and alongside external development partners.
  • Next.js · NestJS
  • GraphQL
  • MinIO · Docker

devgon

Code-first CMS - and the engine behind this site
A universal content layer: build the UI freely in Next.js, then expose any section to admin editing - no backend changes, no schema migrations. One extensible Content entity backs every section, behind a GraphQL API. Full production DevOps owned solo.
How it worksSource
  • Java · Spring Boot
  • React
  • PostgreSQL

carsold.pl

Car marketplace platform, built solo from scratch
Full car listing platform built solo - Spring Boot backend, React frontend, PostgreSQL schema, cloud services and deployment. Custom auth (Google OAuth2, JWT in HttpOnly cookies), real-time chat over WebSocket, admin panel with RBAC, automated content moderation via Google Cloud.
Live siteSource
  • Next.js
  • PostgreSQL · MinIO
  • VPS

Fencing product configurator

Built end-to-end at Budmat, used daily in sales
Built end-to-end - data model, API, calculation logic, UI and deployment - fully parametrized for offer and production capacity. Used daily by 30+ sales representatives, feeding straight into the ordering pipeline. Later extended with 3D visualization.
More about my work
  • TypeScript
  • Calculation engine
  • Internal tooling

PV quoting & BOM tools

Hours of quote preparation cut down to minutes
A suite of quoting and bill-of-materials tools for photovoltaic structures - roof-mount, tracker and carport - with deep product parametrization and calculation algorithms. Adopted across a 20-person engineering and sales division and consumed directly by production.
More about my work
  • React Native
  • GPS · Media
  • Reporting

PV field-inspection app

Smart inspections for photovoltaic farms
A mobile application for field inspections - GPS route tracking, photo capture, defect logging and automated report generation. I contributed alongside requirements, UI and UX, feature design, testing and acceptance criteria.
More about my work
Experience

Where I've done it

Three years of production work - manufacturing systems, internal tooling and my own products, from first requirement to running deployment.
  • Feb 2025 – Present

    Fullstack Engineer

    Budmat - manufacturing group · Płock, Poland (Hybrid)

    Built and shipped a fencing product configurator end-to-end - data model, API, calculation logic, UI and deployment. Used daily by 30+ sales representatives and distributors.

    Worked as part of an external development team on the extended platform version, including interactive 3D fence visualization: feature and business-logic design, API and data-flow decisions, UX, code and full-stack QA.

    Designed and delivered a suite of quoting and BOM tools for photovoltaic structures - adopted across a 20-person division, cutting quote preparation from hours to minutes.

    Contributed to a mobile field-inspection application for PV farms - GPS route tracking, photo capture, defect logging and automated reports.

    Modelled and implemented the division's end-to-end delivery process in Jira for 40+ users - BPMN, custom workflows, automation rules, Google Drive integration.

    Polish (native), English (fluent), German (basic). Agile / Scrum, technical communication in both PL and EN.

  • Sep 2023 – Present

    Fullstack Developer

    Independent projects & freelance · Remote

    Three years of continuous, project-based learning: fullstack development, system design, security and DevOps - every concept validated by shipping something that runs in production.

    Designed, built and operate two production systems end-to-end - architecture, backend, frontend, database schema, cloud services, deployment, tests and UX. One on Java / Spring Boot and React, one on NestJS and Next.js.

    Own full production DevOps: Docker Compose, nginx reverse proxy, GitHub Actions CI/CD, self-hosted Linux VPS, S3-compatible object storage, self-hosted analytics.

    Delivered client websites on a freelance basis, from requirements through deployment and handover.

Let's talk
My process

How I work

The same four steps whether I'm building solo, inside a team or alongside an external development partner.

  1. Understand the problem

    I start with the people who will use it, not the ticket. Requirements, edge cases and the process behind them - before a single line of code.

  2. Design the model

    Data model and API first. Get those right and the UI, the tests and every later feature fall into place instead of fighting each other.

  3. Ship iteratively

    Small, working increments in front of real users early. Feedback shapes the tool while it is still cheap to change.

  4. Own it in production

    Deployment, CI/CD, monitoring and the bug reports that follow. I stay responsible for what I build after it goes live.

What I build with

The stack I use day to day - picked because I have shipped and maintained production systems on it.
TypeScript
React
Next.js
Node.js
NestJS
Java
Spring Boot
PostgreSQL
Docker
Linux VPS
GitHub Actions
Google Cloud Platform
AWS
Jira
Claude Code

About me

Self-taught, production-tested
I learned engineering by building things that had to work - not by collecting certificates. Three years in, that means two production systems of my own and internal tools a manufacturing division relies on every day. I like owning a feature end to end: the data model, the API, the interface, the tests and the deployment. It is the only way I know to make sure the seams hold. I believe software should run like a well-tuned engine - precise, predictable, no surprises. As someone who has always been into cars, I have little patience for half measures. I prefer solutions that are finished and dependable.
Fullstack EngineerJakub Gontarek
Jakub Gontarek

Let's talk

Open to remote roles. Happy to walk you through any of the projects above.

Email

gontarek384@gmail.com

Phone / WhatsApp

Notice period: 1 month. Available for B2B or an employment contract. I read every message and usually reply within 24 hours - my full CV is available on request.