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CHSCrediversoRaylu
Jonathan Tollefson
Design Engineer
jtollefson123@gmail.com · (614) 403-4845 · uxjon.com · Minneapolis, MN · remote (US)

Summary

Five years across marketing, UX, and enterprise data. I now build what I design: front-end, audio tools, and applied AI. Looking for a product team in audio, transcription, or AI.

Selected Builds

AI mastering agent · Python, pedalboard, Claude
2026 – Present
  • Built an agent that masters a mix in a stateful, multi-step run, rendering candidates through FabFilter plugins.
  • Shelved an active-learning model of my taste when blind tests showed it had learned the bias in my unblinded ratings, the known reward-model overoptimization failure.
  • Every candidate is now loudness-matched (ITU-R BS.1770, true-peak limited) and judged blind against the untouched original, which won 26 of 58 votes (one rater, me, June to August 2026).
uxjon.com/case-studies/the-console
Audio catalog and search · Python, Whisper, librosa, Claude
2026 – Present
  • A pipeline I wrote alone transcribes, fingerprints, deduplicates, and classifies about 20,000 audio files by content; a phone app finds any of them by a word.
Browser instrument · TypeScript, Web Audio API
2026 – Present
  • Drum and bass patterns under keys played from the computer keyboard; it records takes as WAV files.

Experience

CHS Inc. · Business Analyst, AI & BI Engineering
Aug 2023 – Present
  • Built agents on the internal AI platform, then designed and wrote the docs, guides, and onboarding chat that teach people to use them; other tools are adopting its design system.
  • Built a Python tool that writes each dbt model's lineage to Excel, Power BI, and stakeholder briefs in one pass.
  • Used AI to find data models missing semantic context and added it in Alation with their developers.
  • Coordinate releases for the go-to-market data engineering team at a Fortune 500 agricultural cooperative; its AI and BI products serve thousands of employees, farmers, and growers.
Raylu, Inc. · Product Designer (Freelance)
Jan – Oct 2023
  • Designed the brand, components, and prototypes for an AI startup; the founders carried them into meetings that closed a $4M seed, and engineers built from the same file.
Crediverso · UX Design Lead
Feb 2021 – Jan 2023
  • Led the design system and onboarding for a bilingual banking app serving US Hispanic households.
  • Ran usability tests with 50+ participants; the revised main flow cut bounce from 40% to 25%.
  • Grew the pre-launch channel from 700 to 2,100 followers with A/B-tested messaging.

Education

Harvard University
2022
A.B. in Sociology, secondary field in History of Science
Dean's List (6×) · Rosenkrantz Discovery Grant
University of Minnesota
2016 – 2018
Transfer years; returned to Harvard to graduate

Skills

Build: TypeScript, React, Astro, HTML/CSS, Python, FastAPI, Claude Code · Design: Figma, Framer, Adobe Creative Suite
Models & Audio: Web Audio API, Claude, Whisper, librosa, demucs, pedalboard · Data: SQL, dbt, Power BI, Alation
Athletics Six-time state hurdles champion; set Minnesota's all-time 110m record and the University of Minnesota freshman record.