Hannes Mühleisen

Hannes Mühleisen is a German-born computer scientist and database researcher based in Amsterdam, best known as the co-creator of DuckDB, the open-source, in-process analytical database that has become a default tool for data scientists and engineers doing fast, local analytics without spinning up a server. He developed DuckDB from 2018 alongside Mark Raasveldt while both were researchers in the Database Architectures group at Centrum Wiskunde & Informatica (CWI), the Dutch national research institute for mathematics and computer science in Amsterdam.

DuckDB was conceived as the analytical counterpart to SQLite: a zero-dependency, embeddable database that runs inside a Python, R or command-line process rather than as a separate server, but is built from the ground up for columnar, vectorised query execution over large datasets. The project's first public version was announced at the SIGMOD conference in Amsterdam in 2019, and it has since become one of the most widely adopted pieces of open-source data infrastructure, embedded inside tools ranging from data science notebooks to production analytics pipelines.

To sustain the project commercially without compromising its open licensing, Mühleisen and Raasveldt spun DuckDB Labs out of CWI in 2021, with Mühleisen as chief executive, and established the independent DuckDB Foundation to hold the project's intellectual property under the MIT licence. The company partnered with the venture-backed MotherDuck from 2022 to bring managed, cloud-hosted DuckDB to enterprises, while continuing to lead open-source development of the core engine.

Mühleisen has continued to hold an academic post at CWI's Database Architectures group alongside his commercial role, publishing widely in top database venues including SIGMOD, VLDB and CIDR, and remains a frequent conference speaker on embedded analytics, hardware-aware database design and lakehouse formats such as DuckLake, which DuckDB Labs introduced in 2025. In 2026 the company rebranded to DuckLabs and announced it was joining Amazon Web Services, while stating its commitment to keeping DuckDB's development open source.

DuckDB's rapid rise — from a research prototype to a tool cited alongside Pandas and Apache Arrow as core modern data infrastructure — has made Mühleisen one of the most consequential figures in open-source database engineering of the past decade, credited with popularising the 'in-process OLAP' category that dozens of subsequent tools now build upon.