Rik Voorhaar

Curriculum Vitae

Work experience
Grazper Technologies

Grazper TechnologiesComputer Vision Engineer

January 2023—Current

Filed 3 patent applications and owned dataset/model licensing compliance — including identifying a licensing issue tainting training data and derived models, and driving a full re-annotation remediation.

Designed a multi-camera 3D pose auto-annotation pipeline: cross-camera association, uncertainty-weighted triangulation in JAX, and optimisation-based temporal filtering. Over 95% of frames met or exceeded human annotation quality on many sequences.

Patched YOLO26 and RTMO to expose per-keypoint uncertainty at inference; calibrated raw outputs to pixel-scale errors for downstream 3D reconstruction.

Built an internal MLOps platform over PostgreSQL — deterministic, cached, distributed component execution powering annotation, evaluation, and training-data pipelines.

Owned pose-model training end-to-end: custom dataset loaders, augmentations, and fine-tuning for production conditions.

Built full-stack internal tools (Python + Svelte): a multi-camera ArUco calibration tool (sub-cm accuracy at 5–10 m, patent filed) and a microservice orchestration manager UI.

Co-maintained core infrastructure as one of two go-to engineers: PostgreSQL, Docker, GitHub Actions, Grafana, and MLflow.

Tracked CV/ML literature and presented internal deep-dives on pose estimation, tracking, and monocular 3D methods.

The Science Breaker

The Science BreakerSenior Scientific Editor (volunteer)

June 2021—Current

Edit layperson summaries of peer-reviewed research for clarity and style.

University of Geneva

University of GenevaDoctoral Candidate

March 2018—December 2022

Pivoted from pure to applied mathematics ~2 years in. Thesis on low-rank tensor methods, randomized linear algebra, and applications to machine learning.

Published 5 papers; 3 accompanied by open-source Python libraries (computational algebra, numerical linear algebra, and machine learning).

Taught 3 courses per year as an assistant, receiving consistent positive feedback from students.

Education
2018/03—2022/12
PhD in Applied Mathematics | University of Geneva
2015—2018
Msc. Mathematical Sciences | Utrecht University (cum laude)
2012—2015
Bsc. Mathematics and Physics & Astronomy (double degree) | Utrecht University (cum laude)
Programming skills
Languages
Python
TypeScript/JavaScript
Rust
C/C++
SQL
LaTeX
ML & CV
PyTorchJAXUltralyticsONNXOpenCVSciPy
Data
NumPypandaspolarsmatplotlibplotly
Backend & database
FastAPIFlaskPostgreSQLSQLAlchemy
Frontend
SvelteTailwind
MLOps & infra
DockerLinuxGitGitHub ActionsGrafanaMLflow
Numerical
CVXPYNumPySciPy
Languages
Native/bilingual
Dutch
English
Intermediate (B1-B2)
French
Danish
Basic (A1-A2)
Japanese
Russian
Spanish
Technical writing
rikvoorhaar.com/blog — 19 technical posts
Machine learning with discretized functions and tensors
Kalman filters and how I made them 20× faster using Rust
Blind deconvolution (4-part series)
Publications
December 2022 (PhD thesis)

Tensor Train Approximations: Riemannian Methods, Randomized Linear Algebra and Applications to Machine Learning

August 2022

Streaming Tensor Train Approximation published in SIAM Journal on Scientific Computing joined work with Bart Vandereycken and Daniel Kressner

March 2022

TTML: tensor trains for general supervised machine learning joined work with Bart Vandereycken

April 2021

On certain Hochschild cohomology groups for the small quantum group published in Journal of Algebra joined work with Nicolas Hemelsoet

November 2019

A computer algorithm for the BGG resolution published in Journal of Algebra joined work with Nicolas Hemelsoet

October 2018

Parallel 2-transport and 2-group torsors

Open source contributions
tt-sketch python package
ttml python package
bgg-cohomology sage package
geoopt
autoray
scipy
Online courses
2021/02
Neuroscience and Neuroimaging Specialization | John Hopkins University (Coursera certificate)
2020/09
Genomic Datascience Specialization | John Hopkins University (Coursera certificate)
2019/08
Advanced Machine Learning Specialization | Higher School of Economics (Coursera certificate)