Joep de Jong
April 2000 - Now


I am a technical student pursuing my Master's degree at TU Delft and currently completing my thesis at TNO. With a keen interest in Mathematics and Computer Science, I have spent several years studying these disciplines. Programming has been my passion since the age of 9, and I am a self-motivated individual with a drive for excellence. By the age of 12, I had already completed my first project for a client, and at 16, I had established my own freelance software development company. Throughout my academic journey, I have continued to take on programming jobs, relishing challenging projects that require me to push beyond my limits. My insatiable thirst for knowledge has always led me to explore the latest technologies and their applications to real-world problems.


I am currently pursuing a Master's degree in Applied Mathematics at the Technical University of Delft. My primary focus is on Numerical Analysis, which is a branch of mathematics that involves solving complex mathematical problems using computer approximations.


Over the years, I have created over 30 websites, and managed and updated more than 100 others. Additionally, I have implemented dozens of APIs, integrating third-party services seamlessly into various web projects.

However, as I continue to grow and develop as a math student, I have chosen to focus my software development efforts on more challenging projects. Specifically, I prefer dedicating my time to complex coding, speed optimizations, security, and scientific computations. These are the areas that provide the greatest opportunity for me to learn and expand my skillset.

Due to my limited time, I am only accepting web design and implementation projects on an exceptional basis. If your project falls within my current focus areas and requires a high level of expertise and creativity, I would be delighted to collaborate with you.

Social impact

Besides my commitment to my studies and work, I'm passionate about making a positive impact on society. I take pleasure in analyzing rules and regulations, and finding innovative solutions to address critical issues. More importantly, I derive immense satisfaction from helping others, and if my work can positively impact the lives of individuals or communities, then it's a truly rewarding pursuit.


As the interest rate on government bonds increased, it became common knowledge that student loan interest rates would also rise in 2023, leading to higher debt for many students. However, I proactively delved into the loan regulations, discovering a loophole where cancelling and reapplying for the loan could help avoid higher rates on the majority of the debt. Sharing my findings with TU Delta, the university's journalistic platform, led to national attention1 on what was dubbed the "rentetruc". Over 26,0002,3 students followed suit, collectively saving tens of millions of euros.

1. TU Delta - TU-student bedenkt truc om hoge studierente te ontwijken.

2. TU Delta - Tienduizenden studenten doen truc met studierente: 'Absurd veel'.

3. NRC - Een lagere rente voor de bulk van je schuld. Het idee van Joep (22) hielp veel pechstudenten.


If you have any questions or would like to discuss a potential project, please feel free to contact me. I am always excited to collaborate and hear new ideas.

+31 6 1399 9469

Encrypted communication

To ensure secure communication, I use various encryption methods, including PGP4 (general) and S/MIME 5 (email). If you would like to communicate with me securely, verify my identity, or give me access to certain applications, you can use one of the following public keys: