Researcher in AI & optimization · Bonn, DE

Alexander Hagg

I build co-creative systems — search algorithms and interfaces that help people explore enormous solution spaces and find options they didn't know they wanted.

PhD
Leiden University
Preference hypervolume, 2021
Currently
OpenSKIZZE-Praxis
CytoTransport
Teaching
Evolutionary computation
since 2011
Portrait of Alexander Hagg human in the loop
Bonn, Germany2026
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01 Position

Most AI tries to hand you the answer. I'm more interested in the space of possible answers — and in tools that let people wander it, argue with it, and make it their own.

The through-line

That question has followed me from robot perception and aerodynamic shape optimization to Quality-Diversity search, VR molecular analysis, and climate-adaptive urban planning.

The methods keep changing. The loop stays the same: model, explore, let a human decide.

Right now

Researching human–AI interaction for molecular science in the DFG project CytoTransport, co-leading the new Digital Twin 4 Multiphysics laboratory, and teaching evolutionary computation across computer science and engineering.

Recently led OpenSKIZZE as PI — a DBU-funded, interactive urban climate project with the German Weather Service's cold-air model inside the loop. Now building OpenSKIZZE-Praxis (2026–2027): a working QGIS plugin that carries the method into everyday planning practice.

Happiest when a domain expert says: “I hadn't considered that option.”

Bonn · 50.7374° N, 7.0982° E
02 Work

Eleven projects,
one question.

OpenSKIZZE's climate-adaptive planning, now heading into QGIS; CytoTransport's molecular interfaces; aerodynamic shape search in AErOmAt — every point is a project or a research thread. The axes are deliberately soft: how much a thing lives in algorithms or the physical world, and whether the machine decides alone or with a person.

All 13 case studies →

11 of 11 projects

↑ more co-creative ↓ more autonomous algorithms → physical world

Hover, tap or focus a pointAxes are a vibe, not a metric

40+student theses
supervised
30+publications
& chapters
15years of
teaching
10research projects
& labs
03 Playground

Four things
to play with.

Working prototypes, not case studies. Search a hidden preference landscape, cool a city block, dock a molecule, or make a mirror duet with the machine. Everything runs locally — open a card and start poking.

Four playable prototypes Runs in your browser · no install · keyboard & touch

04 Path

A non-linear route
through machines and people.

Design, robotics, optimization, co-creation. Each step kept the previous one's question and changed the medium.

2002–2006North Rhine-Westphalia

Freelance graphic & web design

Layout grids, typography, and the first taste of building things people actually use. A useful bias ever since.

2011Fraunhofer IAIS · NIFTi

Human–robot teams for search and rescue

Joined an EU robotics project studying how people and robots share work and attention when the stakes are high.

2012–2016H-BRS · b-it-bots

BSc, MSc and a RoboCup team

Perception for domestic robots with ROS, C++ and Python. The transparent-object work won a best paper at RoboCup 2016.

2016–2019H-BRS · AErOmAt

Fewer simulations, better shapes

Began teaching evolutionary computation and joined AErOmAt, where surrogate-assisted optimization cut the cost of aerodynamic design.

2017–2021LIACS, Leiden University

PhD: Discovering the Preference Hypervolume

Built an interactive model for co-creative Quality-Diversity search with Gaussian processes and VAEs. Defended in 2021; honourable mention for the ACM SIGEVO dissertation award.

2019–2023H-BRS · FullDA-FM / KISs-BiS

From algorithms to planning practice

Led FullDA-FM as PI, turning optimization into urban decision support, and co-authored a systematic review of AI in elite sport.

2023–2025H-BRS · UMMBAS

VR molecules, shared analysis

Collaborative molecular analysis in immersive space, including the MolFuSE virtual-screening framework and co-supervised work on force fields and generative GNNs.

2024–2025H-BRS · OpenSKIZZE · PI

Urban climate as a design space

Led the DBU-funded OpenSKIZZE project: integrated DWD's KLAM_21 cold-air model and built an interactive, surrogate-assisted tool for climate-adaptive neighbourhood planning.

2025–nowH-BRS · CytoTransport / TREE

Human–AI for molecular science

Studying interaction for conformations, force fields and mutation effects, while co-leading the Digital Twin 4 Multiphysics laboratory.

2026–2027H-BRS · OpenSKIZZE-Praxis

From research prototype to a QGIS plugin

Taking OpenSKIZZE into planning practice: a working QGIS plugin that brings interactive, climate-adaptive design into the software planners already use.

05 Craft

The work behind
the work.

A broad toolbox, used with a preference for methods that stay honest about uncertainty and interfaces that stay legible to the person using them.

An older person in a cardigan studies a branching network diagram at a desk, thread-connected cards pinned above. 01 / Models

Learning from stubborn data

Applied ML for scientific and spatial problems, where samples are few, simulations are expensive, and “just add data” is not an option.

  • U-Net
  • GNNs
  • Diffusion models
  • Gaussian processes
  • Random forests
  • Ensembles
  • PyTorch
  • scikit-learn
A young woman with a lantern stands in a vast archive, facing a constellation of countless candidate cards. 02 / Search

Many good answers, not one

Quality-Diversity and surrogate-assisted optimization for problems with expensive simulators, many trade-offs, and a human choosing the final move.

  • Quality-Diversity
  • Surrogate-assisted optimization
  • Multi-objective
  • Evolutionary computation
  • pyribs
A human hand with a pencil and a mechanical drafting hand with a pen meet over a faintly glowing drawing surface. 03 / Interfaces

Keeping the human in the loop

Co-creative interfaces, immersive analysis and agentic tooling — built so that domain experts steer the search instead of watching it happen.

  • Human–AI interaction
  • VR / AR
  • Visual analytics
  • QGIS plugin
  • LLM agents
  • Cline / Roo Code
  • Pi / Oh My Pi
  • OpenRig
An older mentor leans over blueprints with two students, guiding them from a sketch toward a small physical model. 04 / Practice

Shipping it, funding it, teaching it

Research that runs: Python and C++ systems, robotics middleware, project leadership, grant writing, and a lot of supervised student work.

  • Python
  • C / C++
  • Linux
  • ROS
  • OpenCV
  • PI & grant writing
  • Teaching
06 Life

Off the clock,
still making things.

Co-creation is not only a research topic. It is also how I like to spend a Sunday: with musicians, gardeners, cooks, and sentences that take too long to finish.

I grew up Dutch, live in Bonn, and move between German, English and Dutch without noticing. Most of my best thinking happens away from a screen — on a hiking trail, at a piano, or while something is simmering.

“The interesting moment is when a tool stops feeling like a tool and starts feeling like a collaborator.”

I am also part of Neue Stadtgärtnerei Bonn, a grassroots project for socially and ecologically sustainable housing, urban agriculture and education in the middle of the city.

  • Dutchnative
  • Germanfluent
  • Englishfluent
A man plays a grand piano alone at night, eyes closed, one hand lifted above the keys.

Music

Neoclassical piano and improvisation. The best ideas tend to arrive while playing badly.

A writer reads back a handwritten page at a lamplit desk, a stack of finished pages beside her.

Writing

A novel in progress, aiming for publication in 2027. Fiction is optimization without a loss function.

An Indonesian woman tosses a wok in a home kitchen, steam rising among spice jars and shallots.

Cooking

Indonesian kitchen. Recipes are reproducible; the good ones rarely are.

An older gardener kneels by a raised seedling bed at the city edge, pressing soil around young plants.

Growing

Neue Stadtgärtnerei Bonn: sustainable housing, urban agriculture and education in the city.

A lone cyclist climbs a rainy moorland road, small against dark hills and low cloud.

Outside

Hiking and cycling. Thinking at a walking pace, preferably with a hill in front of me.

A seated woman rests her chin on her hand while abstract ideas orbit her in the dark.

Questions

Philosophy of intelligence, geopolitics, European politics. Still trying to define the first one.