Felix Wunderlich

CGO Opper AI | Co-Founder FinetuneDB

Stockholm, Stockholm County, Sweden

About

I'm part of the leadership team at Opper AI, joining through the acquisition of FinetuneDB, the AI fine-tuning platform I founded. FinetuneDB streamlines the creation and management of datasets to fine-tune LLMs to improve performance at lower cost. Prior to FinetuneDB, I founded PenPal, the most popular app to find a pen pal, with a six-figure global user base.

Experience

  • Chief Growth Officer at Opper AI
    Aug 2025 - Present · 11 mos

    Wrote the car wash test opper.ai/blog/car-wash-test and built AI Roundtable askroundtable.ai

  • Co-Founder & CEO (Acquired) at FinetuneDB
    Aug 2023 - Jul 2025 · 2 yrs

    FinetuneDB is the AI fine-tuning platform. Easily create and manage datasets to fine-tune LLMs to get cheaper, faster, and better performing AI models. Acquired by Opper AI.

  • Traction Fellow at EWOR
    Mar 2025 - Jun 2025 · 4 mos

    EWOR is a highly selective founder fellowship that backs exceptional entrepreneurs with capital and hands-on mentorship from unicorn founders, helping them build global-scale companies.

  • Mentor STEP USA at German American Chamber of Commerce, Inc.
    2018 - 2025 · 7 yrs

    Mentoring German companies in New York that are part of the GACC STEP USA program. Learn more about bringing your startup to the US: https://stepusa.io

  • Co-Founder & CEO at PenPal
    Jan 2021 - Jul 2023 · 2 yrs 7 mos

    Co-founded and led PenPal, a social platform where people match, chat, and exchange real postcards without ever sharing their address. Took it from idea to a six-figure global user base and 500k+ monthly interactions before its acquisition by MyPostcard in 2023.