Hello World

My name is Jonathan Ullrich. I am a software engineer at the Fraunhofer Institute for Experimental Software Engineering (IESE) and external PhD student at the University of Duisburg-Essen. My PhD is supervised by Prof. Dr. Andreas Vogelsang.

Research interest

I am interested in the early phases of the software engineering process, i.e. requirements engineering and software design.

Artificial Intelligence for Software Engineering (AI4SE)

My PhD research investigates how requirements and design constraints, defined during the early stages of the software engineering process, can be systematically extracted and enforced in LLM-generated code using techniques such as constrained decoding (preliminary title: 'Asserting Requirements and Design Constraints in LLM-Generated Code').

I have been selected for the Software Campus Program (Cohort 2025) for a proposal related to my PhD topic. The program includes an individual research project with an industry partner and a funding of up to 115 000€.

Publications

• Ullrich, J., Koch, M., & Vogelsang, A. (2025). From Requirements to Code: Understanding Developer Practices in LLM-Assisted Software Engineering. arXiv preprint arXiv:2507.07548. Accepted at 33rd IEEE International Requirements Engineering (RE) 2025 conference (Conference Core Rank: A)

List of selected projects

• Marktplatz Deutschland.Digital : Product ownership and design of a system to evaluate open-source repositories on a marketplace for municipalities.
• One Viewpoint for Medical Information in Clinical Contexts : Responsible for requirements elicitation and documentation.
• Neighborhood Diagnostics : Mobile and front end development.
• Study on AI in smart cities : Advisor for AI use cases.
• Master thesis : Empirical experiment to evaluate the influence of different prompting methods on the ability of LLMs to generate code that solves operations research problems.
• Hackathons: I was part of the organization team behind a series of awesome hackathons.

Misc

I like board games and water sports. You can find my boardgame collection on Boardgame Geek.