Justus Mattern

Co-Founder

United States5 yrs 1 mo experience

Key Highlights

  • Co-Founder of multiple innovative tech startups.
  • Expert in reinforcement learning and federated learning.
  • Developed production-level animation tools for video editing.
Stackforce AI infers this person is a SaaS and AI/ML expert with a strong entrepreneurial background.

Contact

LinkedIn

About

https://justusmattern.com

Experience

5 yrs 1 mo
Total Experience
1 yr 1 mo
Average Tenure
9 mos
Current Experience

Proximal

Co-Founder

Sep 2025 – Present · 9 mos

  • Superhuman coding agents

Prime intellect

Research Engineer

Dec 2024 – Aug 2025 · 8 mos · San Francisco Bay Area

  • Started efforts on Reinforcement Learning, core contributor to prime-rl, INTELLECT-2 and INTELLECT-3

Revideo (yc s23)

Co-Founder

Apr 2023 – Nov 2024 · 1 yr 7 mos · Berlin, Germany

  • Built an animation library used in production by several video editing companies. Struggled to monetize

Dynamofl

Research Engineer

Aug 2022 – Apr 2023 · 8 mos

  • Early team. Built federated learning product and LLM fine-tuning platform

Max planck institute for intelligent systems

Researcher

Mar 2021 – Sep 2022 · 1 yr 6 mos · Tübingen, Baden-Württemberg, Germany

  • Worked on causal inference and ML with security guarantees (differential privacy & provable adversarial robustness)

Education

RWTH Aachen University

Physics & CS

Jan 2020 – Jan 2023

Technische Universität Darmstadt

Physics

Jan 2019 – Jan 2020

Justus Mattern - Co-Founder | Stackforce