Wouter Geraedts

Wouter Geraedts

Freelance Software Engineer


Working full-time as a freelance software and hardware developer under the name of Sarif. Has a strong affinity for beautiful code and correct software.

Actively advocates the use of Rust as both a member of the Dutch Rust Foundation and organizer of RustFest. Is proud to have several embedded software projects running in the field.


  • Embedded Software
  • Embedded Hardware
  • Security Engineering
  • Process Automation


  • MSc in Software Science, 2019

    Radboud Universiteit Nijmegen

  • BSc in Computer Science, 2013

    Radboud Universiteit Nijmegen


LED beamer

Device with multiple PCBs featuring a single LED element and radar ranging safety sensor.

LTE-M module

Battery powered LTE-M+GPS device.

ESP32 PHY + Camera

PHY and camera application for ESP32.

IRMA projects

Various authentication services


Carthographic data as REST API service.

ECG Holter Patch

Rust firmware for an ECG Recorder.



Freelance developer

Dutch IoT Solutions

Mar 2021 – Present Den Bosch, The Netherlands
Development of both firmware and hardware for various LTE connected devices and use-cases. Coordinated with manufacturers on the design and manufacture of packaging, components and PCBs.

Freelance developer

Redfig LLC

Sep 2020 – Jul 2021 Remote
Development of a scheduling optimization solver as a REST API service. Worked with the remote development team on forming the API, model and optimization constraints.

Freelance developer


Jul 2020 – Present Nijmegen, The Netherlands
Started off as development of drivers for the managed ethernet switch chipsets LAN9354, LAN9303 and KSZ8863RLL. These drivers implement virtual PHY devices for a ESP32-based appliance. At completion I transitioned to general hardware R&D for the company.

Freelance developer


Oct 2019 – May 2021 Arnhem, The Netherlands
Worked on two separate projects at SIDN. Firstly implemented an authentication bridge between the IRMA and SAML2 protocols in Java. Secondly I guided the adoption of a proprietary Identity and Access Management solution for all their tools, both internal and external for various programming languages and environments. Worked together with multiple teams to adopt this new solution.

Freelance developer

Privacy By Design

Jul 2019 – Feb 2020 Nijmegen, The Netherlands
Independently designed and implemented an encryption scheme for e-mail using Identity Based Encryption and elliptic curves. Core cryptography was written in core Rust with zero allocations, memory safety guarantees and constant time execution. I setup core server infrastructure, and provided Proof of Concept applications both for the command-line and in the Thunderbird e-mail client. This work has been presented at various conferences.

Software Engineer

Tweede golf

Sep 2015 – Dec 2020 Nijmegen, The Netherlands
Until July 2019 I have worked full-time at tweede golf as a software engineer, both in the roles as technical developer and project lead in teams consisting of up to four developers. Since then I have worked part-time at tweede golf on select projects. In this time I have worked with various programming languages and advanced the general knowledge base of the company by leading research efforts. Besides programming I’ve been responsible for system and network operations of our infrastructure, as well as pioneering our use of the programming language Rust, the development of embedded devices, and infrastructure on Kubernetes clusters.

Security Auditor

Laboratory for Quality Software

Jan 2015 – Sep 2015 Nijmegen, The Netherlands
As part of the academic spin-off LaQuSo I have performed security penetration tests and assessments for the Dutch government. Most notably I have been involved in several audits of both the mobile apps of Berichtenbox and DigiD (which provide the digital identity and services to all Dutch citizens and companies), and have been able to provide the client with major security issues by reverse engineering assembly in black-box assessments. Besides performing penetration tests I have delivered clearly written assessment reports detailing issues, assessing their impact and suggesting mitigations.



Jan 2007 – Jan 2011 Beneden-Leeuwen, The Netherlands
As one of the two programmers at the company I was responsible for my own projects, building on and improving on our in-house CMS.


Hacker Games hackathon

Won a national hackathon with our solution in which by keeping track of your daily morning routine and your travel time (including prediction of travel and/or train delay) your alarm-setting could change in order that you can get enough sleep (or as much as possible). The team won a trip to Silicon Valley.

1st place THF division at CASC-J7 2014

Entered into CASC with my theorem provers VanHElsing and Satallax‑MaLeS. With Satallax-MaLeS got 1st place in the THF division. VanHElsing came in on 4th place in the FOF division.

Aia Bachelor Award

Received the Aia Bachelor Award for my bachelor’s thesis on ‘Time-based Modeling and Verification of Flow Systems in Uppaal’.