JKCTech

Jeffrey Koopman

Software Developer / Ethical Hacker / Freelancer

I am a 26 year old telecommunications engineer and part-time software developer from The Netherlands. I build creative tools, explore tech systems, and share insights through code and projects. From electronics and tools to open-source software and radio tech, I love turning ideas into working solutions.

View Portfolio Buy Me A Coffee

Spotting & Photography

Model Building

Featured Projects

Quinine

Filter third-party sellers from Amazon & Bol.com automatically.

28-05-2025

AmberLoader

JS module that detects and displays Amber Alerts on websites.

28-05-2025

Magnet2Deluge

Browser extension to directly send magnet links to your Deluge instance.

06-07-2025

112Centraal

Realtime notifications from the Dutch emergency services and aviation radar.

23-10-2019

Speedtest Faker

Generate fake Speedtest results, hosted on the real Speedtest website.

27-03-2018

Zalgo Text Generator

Create zalgo text to mess with your friends.

22-08-2018

More Projects

External Mentions

Dutch Coastguard

Dutch Coastguard

01-08-2020

From August 2020 to February 2022 the Dutch Coastguard promoted the use of my aviation radar.

Volkskrant

16-03-2022

A news article covering the Twitter bot which I created the software for.

Texelse Courant

Texelse Courant

17-04-2026

Working as a telecom engineer I piloted the migration of Kabeltex customers to the KPN network on the island of Texel.

Latest Blog Posts

Quinine

Filter third-party sellers from Amazon & Bol.com automatically.

16-07-2025

Vereisten Op Ziggo Modems Omzeilen

Soms, heb je nou nét iets nodig wat je modem / router niet kan bieden.

16-09-2022

My Radar Box Setup

My custom radar box for receiving airplane and pager signals.

13-07-2022

Detecting Police Presence?

Detecting the presence of emergency services by radio signals.

21-04-2022

Tracking Planes on Twitter

How I made a bot tracking Max Verstappen's private jet on Twitter

21-04-2022

Impact with F12

How I injected a custom highscore in a minigame from NS called "Impact With Your Code".

13-04-2022

Telegram Trilateration

Proof of concept for abusing Telegram's "People Near Me" feature and tracking people's location.

17-02-2022

Logo Workshop

A (Dutch) mini-workshop in LOGO for teenagers.

01-08-2021

Getting Started With Arduino

A short crash course into electronics and Arduino!

27-01-2020