My name is Elias, I'm a Dutch software developer active in the Amsterdam area. Currently I am finishing up my Master's degree in Computer Security at the Vrije Universiteit (VU) while building and consulting at Defined Once Engineering B.V. as a systems software engineer and co-founder.
In this role, I have led software engineering teams from 3 to 5 people, where I normally take on the role of the chameleon. As such, I became fluent in Dutch, English, C, Go, Rust and TypeScript.
A resume overview can be found at the bottom of this page.
Me, presenting the Autonomous Systems Engineering (ASE) Rover, one of the projects I have designed and supervised for Bachelor Computer Science students at the VU.
Computers and I
"Computers have always fascinated me" is something that feels mandatory to say when trying to qualify yourself as a seasoned developer, but that does not make it any less true for me. They have. Since my early beginnings.
When I was eight years old, my dad brought home an old laptop for me. It ran ubuntu and was not at all powerful enough for any games. That never bothered me - I am not much of a gamer anyway. It allowed me to try to satisfy my curiosity for the digital unknown, from making my own web pages, to learning how to make Flash animations, and from opening reverse android shells on Kali Linux to editing my own vlogs.
When I was 11, I was responsible for helping teachers with printer drivers and remote desktop installations, which I kept doing for others as PChulp Castricum (a name that worked great on Google). At 15, I used this business to develop PHP web applications. My mom was the first customer (she needed some place to manage the administration of her Yoga studio, including automated invoice sending) but other projects (a post card management system, a small social network and automated inventory syncing) quickly followed. Solving puzzles in a creative manner turned out to be an energizing combination for me. Sometimes it was a dangerous one too: during Covid, I almost got into trouble for experimenting with the online exam software when I wanted to try and see if I could circumvent the remote monitoring.
It surprised really no-one that I enrolled in the Computer Science Bachelor's at the Vrije Universiteit Amsterdam. There, I got to understand computers at the foundational level. I participated in the global NXP cup (which our team won) and I kept delivering software through my business. One year later I returned to the VU for a Master's in Computer Security with the renowned VUSec group.
While low-level systems and their security allow for ample opportunity in puzzle solving, it started to bother me that there was so little resistance to the status quo. It became clear to me that the surface for potential failures is uncomfortably big: the brightest minds of the last generation have built really advanced tools on really primitive ones. I consider it the task of my generation to now learn from them to solidify and re-host the foundations almost all of society relies on. Fully aware that there is no silver bullet, I like to see myself as curious enough to not accept anything as is, but humble enough to recognize that we must learn from the legends on whose shoulders we stand. The urgency I feel, has fueled the co-founding of Defined Once.
Resume
My passion lies in systems engineering work, but I have extensive experience with building backends (from Axum to Nest), front-ends (from Vanilla to Svelte), deployment pipelines (from Github Actions to Kubernetes, with Terraform and Pulumi) and low-level systems (most notably, building my own, functional, kernel from scratch).
Career
From 2017 until 2023, I have been active as a freelance developer and technical support. This started as "PChulp Castricum", where I helped to solve technical problems on location. This mostly involved setting up WiFi, restoring bricked Windows setups and installing printers (it's always the printers). From 2020 onwards my work shifted towards software development.
Since 2023, I am the founder of LJZ Digital Solutions B.V. at which I lead, build and consult the development of digital solutions for business and education. I like to be on both ends: in contact with the client and end user, as well as in the technical land where I can express myself through code.
In 2026, LJZ has become part of Defined Once Engineering B.V., which I co-founded with Max Gallup. Here, we focus on systems engineering work for companies that need their foundations ported to the 21st century.
As volunteering work, I help organizing elections in my hometown.
Education
I have received my pre-university diploma (VWO, gymnasium) in 2020. After this, I started my Bachelor's Computer Science at the VU, where I specialized in security and (distributed) programming in the Deep Programming minor. In 2023, I received my Bachelor's degree cum laude, with a 9.0 GPA.
From September 2023 until August 2024, I have taken a gap year to focus on LJZ and client work. In September 2024 I went back to the VU to pursue my Master's in Computer Security.
Projects
There are plenty! I've been active in many projects since I was young: from building a small scale social network in PHP to deploying browser-based binary explorers. You can find some of my work on Codeberg. A few projects that deserve highlighting:
In 2017, I first got into contact with programming, by developing an invoicing and customer management system in PHP. I like to put it on the list, because it did not only teach me the fundamentals of PHP, JavaScript and HTML, but sparked my interest in programming in general.
In 2022, I worked as a teaching assistant for the VU's Systems Programming Project. To help me explain the important concepts to students, I built IJVMore, an IJVM inspector, debugger and scripting tool that runs in your browser. In 2025 I rebuilt the project in Rust to get some experience with WebAssembly, but that version is not deployed yet.
In 2023, I was the lead developer in my own team for the first time. In a team of three, we created Cadens, an interactive online learning module for dental care students. I liked to work on CI/CD, working with a lot of Docker, Kubernetes and Terraform, but I also built the front- and backend. It is a project that grew my love for TypeScript and types in general.
Since 2021, I have been part of Project Autonomous Driving at the VU, where I participated in the NXP Cup with my own autonomous vehicle. In 2023, I led the software development and course creation of the new Autonomous Systems Engineering labs at the VU. With this framework, we won the NXP cup in 2024. After that, I have supervised two rounds of Bachelor Computer Science students at the VU until 2025.
In 2021, I first got in touch with building operating systems by building my own memory allocator. In 2025 I have built my own kernel from scratch. Both projects cannot be shared publicly, but I can show them when interested.
Since 2017, I have been participating in Google Hashcode at the STORM hub in Amsterdam. I always enjoyed these nights of puzzle solving, coding and pizza. Unfortunately, Google discontinued Hashcode. Maybe it wouldn't be as fun in the AI era anyway...
Media
Darian Janevski, Natalia Silvis, me and Max Gallup after presenting at the ITiCSE conference in Nijmegen, July 2025
Me (left) and the team (Max Gallup, Natalia Silvis and Niels Althuisius) winning the Science Faculty's education impact award for the Autonomous Systems Engineering project of which I co-led, February 2026
Max Gallup, Darian Janevski and I presenting the Autonomous Systems Engineering (ASE) labs at ITiCSE Nijmegen, July 2025.