Lars Grammel
Software Engineer, AI SDK at Vercel
Berlin Metropolitan Area Germany
Summary
🤩
Rockstar🎓
Top SchoolLars Grammel is a seasoned software engineer and AI SDK specialist based in Berlin with 14 years of experience building production-grade web and data tools. He combines hands-on backend engineering—recently contributing to Vercel’s popular vercel/ai SDK by improving API stability, telemetry, and file upload support—with deep product and team leadership from founding startups and scaling Trifacta’s Berlin office. His background spans data prep, visualization and developer tooling, including notable contributions to the Vega visualization grammar’s test suite and shipping core JavaScript UX for Trifacta’s data transformation products. Lars blends research rigor (PhD work on visualization interfaces) with pragmatic engineering, often bridging prototype research into production features. He’s comfortable recruiting, growing teams, and steering cross-functional projects while still shipping code that improves developer and user experiences. An understated strength is his knack for turning visualization and data-prep research ideas into robust, testable software used in real products.
14 years of coding experience
22 years of employment as a software developer
PhD, Computer Science, PhD, Computer Science at University of VictoriaMaster, Computer Science, Master, Computer Science at RWTH Aachen University
English, German, French
Stackoverflow
2,098reputation
206kreached
25answers
5questions
Github Skills (17)
unit-testing10
javascript10
testing10
typescript10
typescript-types10
typescripts10
telemetry10
githubactions9
apidoc9
api9
xml6
heroku6
gwt6
docker6
github6
Programming languages (9)
Github contributions (5)
vercel/ai
Jul 2023 - Apr 2025
The AI Toolkit for TypeScript. From the creators of Next.js, the AI SDK is a free open-source library for building AI-powered applications and agents
Role in this project:
Back-end Developer
Back-end DeveloperContributions:1526 reviews, 2869 PRs, 4746 pushes in 1 year 9 months
Contributions summary:Lars primarily contributed to the core functionality of the AI SDK, making various changes to enhance its capabilities. The commits involve updating model lists, adding telemetry for improved tracking, and adding support for file uploads. The changes indicate the user's involvement in improving API stability, adding features, and implementing quality-of-life improvements like enabling file uploads.
anthropicartificial-intelligencegeminigenerative-aigenerative-ui
vega/vega
Apr 2013 - Sep 2020
A visualization grammar.
Role in this project:QA Engineer / Test Automation Engineer
QA Engineer / Test Automation EngineerContributions:8 reviews, 25 commits, 10 PRs in 7 years 6 months
Contributions summary:Lars primarily contributed to the project by adding unit tests and test setups. Their work involved writing test cases for the project's core functions, particularly for the `vg` namespace. They focused on testing functions like `isNumber`, `array`, `unique`, `keys`, `values`, and `str`, ensuring the reliability and correctness of the visualization grammar's utility functions. The commits demonstrate a focus on comprehensive testing of the library's foundational components.
svgcanvasgrammarvegavisualization-grammar
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