Sem de Jong

Web Developer

Web developer based in the Netherlands, specializing in building fast, modern websites with Next.js and a strong focus on design and performance.

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Work Experience

Backdesign

CEO

Nov 2021 — Sep 2025

As CEO of Backdesign, I designed and created custom websites for companies, among others.

Bundles and Batches

Internship

Sep 2021 — Oct 2021

For my internship during high school, I chose to do an internship at Bundles and Batches. Here, I learned a lot about working with React.

Jumbo Koornneef

Shelf stocker

2019 — 2021

I worked as a shelf stocker at Jumbo Koornneef in Wateringen. This gave me experience in communicating with customers.

Pixelnode

CEO

2018 — 2020

As CEO of Pixelnode, I primarily offered game servers to customers. To this end, I designed and created a complete hosting panel with PHP and Laravel.

Featured Projects

TimeDrop

Webapp for viewing and creating timetables & lineups for festivals and raves.

Test credentials: admin@timedrop.nl, admin

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ReserveMate

Reservation management app for meeting rooms and workspaces.

Test credentials: admin@reservemate.nl, admin

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GiftGPT

AI-powered gift recommendation app that suggests personalized gifts based on user input.

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About Me

Hi, I’m Sem de Jong — a creative web developer from the Netherlands. I’m passionate about building fast, modern, and engaging websites using Next.js and React. I love turning design concepts into clean, responsive interfaces that feel effortless to use. My work focuses on combining sleek design with solid performance, creating digital experiences that are both beautiful and built to last. Whether it’s developing from scratch or optimizing existing projects, I enjoy finding the perfect balance between creativity, usability, and technical precision.

Resume (English) Resume (Dutch)