Portrait of Björn C. Schiffler

Björn C. Schiffler

I’m a Staff Data Scientist at Vend in Stockholm, with a PhD in cognitive neuroscience.

Selected work

Research and side projects

Side project · since 2026

Poly­mathic

A free learning app that I build on my own. It has short explanations of more than 450 ideas from science, art, history and philosophy. You answer questions in your own words, and spaced repetition schedules your reviews. The Astrolabe is a map of how the ideas connect, and the Chronicle is a game where you place historical figures in their era.

Visit polymathic.app
Enlarge: Screenshot of the recommender: a username search above a row of recommended film posters

Side project

Letterboxd movie & user recommender

I built a movie and user recommender for members of Letterboxd, a social network for rating movies. Anyone who had rated about 100 movies or more could enter their username and get recommendations for movies and like-minded users, or see recommendations for a random user. The recommender is no longer online.

Side project

Semantic similarity of scientific journals

Using abstracts from 123 scientific journals, I created a semantic fingerprint of each journal with the cortical.io API and compared the journals in an interactive matrix built in Python with Bokeh.

Enlarge: Violin plots of drift diffusion model parameters after correct and error trials

PhD research

Modelling latent decision processes

In my PhD I used computational models such as reinforcement learning and drift diffusion models, fitted to reaction times and accuracy, together with neuroimaging analyses to make inferences about the decision processes underlying adaptation to errors.

Postdoc · Karolinska Institutet

Standardized neuroimaging preprocessing

I built an fMRI preprocessing and quality-control pipeline based on Docker/Singularity containers and BIDS tools, for large-scale analysis of dynamic functional connectivity in chronic pain.

About

I’m broadly interested in technology and AI development. Outside of work I enjoy travelling, playing tennis and chess, and listening to post-rock.