Portfolio
Updated 2026 · 08
01 · Profile

Daniel Dratschuk.

Founder of Clef, a piano learning app that schedules practice the way Anki schedules flashcards. It builds on my research in AI systems, optical music recognition, and tools that accelerate human learning.

02 / Now

What I'm building

Founder · Live since July 2026
Clef · playclef.com

Clef — spaced repetition for piano, over MIDI.

A web app for memorizing piano repertoire. You play over MIDI and every note is graded. FSRS spaced repetition decides which bars to review, the same algorithm Anki uses for flashcards.

In production with the full loop live. MIDI grading in the browser, FSRS scheduling, score catalog, and billing. The catalog is populated from public-domain scans by Transcoda, the OMR model below.

03 / Publications

Current research

Under review · NeurIPS 2026
arXiv · 2026

Transcoda — End-to-end zero-shot optical music recognition via data-centric synthetic training.

An optical music recognition system built around synthetic data generation, normalized Humdrum **kern output, and grammar-based decoding for syntactically valid transcriptions.

A compact 59M-parameter model trained in six hours on a single GPU, outperforming billion-parameter baselines on synthetic and historical scan benchmarks.

04 / Applied ML

Production ML in industry

Commercial engagement · Shipped 2026
OBI · obi.de

Classifying 1.6M product images for OBI's online catalog.

End-to-end design and delivery: catalog ingestion, a custom keyboard-first labeling tool, active learning with a Cleanlab label audit, and a category-conditioned DINOv3 ViT-L classifier (304M parameters) served in production over gRPC.

26,920 human labels → macro-F1 0.82 across 11 photo-type classes; the full 1.65M-image catalog scored in 11.5 hours on a single GPU, 88% of predictions above 0.9 confidence.

05 / Engineering

Selected open-source (C++, Rust & C)

06 / Education

Heinrich-Heine-Universität, Düsseldorf

B.Sc. and M.Sc. in Mathematics

Grade 1.1 (German scale) · 2020 — 2025
ThesisReinforcement Learning

B.Sc. in Computer Science

Grade 1.1 (German scale) · 2020 — 2026
ThesisOptical Music Recognition (→ Transcoda)
07 / Languages

Reading, writing, speaking

German
Native
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English
Fluent
-
Japanese
Fluent
JLPT N1 · self-taught
Russian
Advanced
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08 / Music

Piano

09 / Writing

Recent notes

© 2026 Daniel Dratschuk