Lorenz is an Algorithm Engineer for Big Data, algorithms researcher, and experienced high-performance modern C++ programmer. He works as a Software Engineer on Firebolt's Query Processing team, building the cloud data warehouse of the future. Before that, he completed his PhD thesis at KIT. His research focuses on probabilistic distributed algorithms for Big Data problems.
Software Engineer — Firebolt Analytics
Since September 2021
Working on the vectorised query engine of Firebolt’s cloud data warehouse, including feature development, performance optimisation, and stability.
PostDoc in Algorithm Engineering — KIT
December 2020 – September 2021
Focus: static approximate membership query & retrieval (perfect hash static function) data structures. Designed and implemented BuRR (bumped ribbon retrieval), a retrieval and static approximate membership query (AMQ) data structure with sub-1% space overhead and query times on the order of a single cache miss.
Other Responsibilities included supervising BSc and MSc thesis projects and course work, coordinating a high-performance computing (HPC) project, and leading seminars and exercises.
Doctoral Researcher — KIT
December 2014 – November 2020, Algorithm Engineering Group
Focus: Parallel & Distributed Algorithms for Big Data Problems
Thesis: Communication-Efficient Probabilistic Algorithms: Selection, Sampling, and Checking, Advisor: Peter Sanders
Designed, analysed, and implemented probabilistic run-time correctness verification for fundamental operations (aggregations, sorting, …) in Thrill, an Apache Spark-like research prototype 
Presented the first parallel algorithm for constructing alias tables, a popular data structure for sampling from discrete distributions and an open problem for decades; the first algorithm that requires time linear in the output size for sampling with replacement from discrete distributions 
Developed communication-efficient algorithms for various selection problems, bulk priority queues, and (weighted) reservoir sampling , 
A full list of my publications is available on my Google Scholar page
Other Responsibilities included supervising BSc and MSc thesis projects and course work, coordinating a high- performance computing (HPC) project, and leading seminars and exercises
Maintainer — Glowing Bear
Developer and Maintainer of Glowing Bear, a web-based IRC frontend using WebSockets
Undergraduate Teaching Assistant — KIT
2010/2011 & 2012/2013
Tutoring students and correction of weekly assignments of the lectures “Algorithmen 1” and “Programmierparadigmen”.
MSc in Computer Science — University of Leicester
Graduated with Distinction
Thesis: “Compression Methods for Labelled Trees”, Advisor: Rajeev Raman.
BSc in Computer Science — KIT
Thesis: “Speed–Consumption Trade-Off for Electric Vehicle Routing”, Advisor: Dorothea Wagner.