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Jan Matas

Co-founder & CTO at Kontext

hi@janmatas.com Download resume (PDF)

Education

2014 - 2018 Imperial College London | MEng Computing (AI)

  • Awarded the Governors' Prize for the top graduating MEng student in 2018 (87.5%, best overall in class).
  • Other prizes: Formicary Software Engineering Prize, G-Research Prize (twice), Morgan Stanley IT Prize.

Work Experience

2023 - Present Kontext | Co-founder, CTO

  • Founded an AI-native advertising platform that uses LLMs to serve contextually relevant ads inside GenAI apps; raised ~$10M seed and now lead a team of 7 engineers.
  • Built the full serving stack on our own finetuned models running on vLLM on custom GPU infrastructure, delivering 20M+ hyperpersonalized ads/day and 2k+ RPS of DSP traffic.
  • Designed the eval harness and ran post-training (SFT + DPO + GRPO) on open-weight base models to deliver brand-safe, on-policy ads even in NSFW and adversarial contexts.

2019 - 2023 Deepnote | Founding CTO

  • Co-founded Deepnote, a collaborative data science notebook; architected the original platform (still in production today).
  • Grew engineering from 2 to 20 engineers through Seed and Series A, building out processes as the company scaled.
  • Scaled to 500k+ users across enterprise (Fortune 500), regulated industries (e.g. Norway's sovereign wealth fund), non-profits (e.g. Gates Foundation), and academia (e.g. MIT robotics).
  • Owned SOC 2 Type II and HIPAA-compliant deployments to unblock regulated enterprise sales; built out security, compliance, and multi-cloud deployment infrastructure.

2018 - 2019 Two Sigma | Software engineer

  • Implemented new execution scheduler significantly increasing model prediction speed (Java).
  • Adapted internal build mechanisms to work with new Python APIs.

2017 Palantir | Software engineer (intern)

  • Full stack development of data analytics tool for a customer (Java, Typescript, ElasticSearch)
  • Implemented recommendation system based on the content similarity of analyzed documents
  • Significantly improved search relevance and performance, improved data pipeline reliability
  • Iterated with users on functionality and UX of multiple features during onsite visits

2016 Google | Site reliability engineer (intern)

  • Created a system for analyzing per video resource usage in YouTube ContentID system
  • Built an AB load-testing infrastructure using traffic replays for a new ContentID index

Publications

Matas, J., James, S., Davison, A.J. (2018). Sim-to-Real Reinforcement Learning for Deformable Object Manipulation. in Conference on Robot Learning (CoRL) 2018 - 500+ citations - arxiv.org/abs/1806.07851

Notable awards

  • Forbes 30 Under 30 Slovakia
  • O-1 Visa - US "extraordinary ability" classification

Notable projects

  • Learning end-to-end robotic manipulation of deformable objects (Python, Tensorflow, Physics simulators)
  • Global Air Traffic Management For UAVs - in association Microsoft (C#, Python)
    • Palantir Forward Group Project Prize for outstanding third year group project - news.microsoft.com
  • Neural networks - character recognition and traveling salesman problem using recurrent neural network (Java)
    • CPP prize for best project in category, team leader (5 imperial students)
  • Improving Code Completion with Machine Learning (GPT2, LSTM)
  • AREROS - autonomous rescue robotic system able to navigate in dangerous environments
    • Intel ISEF 2012 – Finalist, World championship in robotics RoboCup jr. 2011 - 1st place

Skills

  • Python
  • TypeScript
  • Java
  • SQL
  • LLM post-training (SFT, DPO, GRPO)
  • Evals
  • PyTorch
  • vLLM
  • ClickHouse
  • Postgres
  • Kubernetes
  • GCP
  • AWS
  • Compliance
  • Hiring
  • Eng Management