Stef Lewandowski

Fractional CTO / tech lead working on applied AI

I’m an experienced early-stage startup tech/product lead with a mix of overlapping skills in software development, design, and business model innovation.

Throughout my career, I’ve sought to find repeatable ways to discover new opportunities, prototype and develop early-stage tech startups and scale them to have an impact on solving problems the world faces.

Stef Lewandowski



  • On Deck

    On Deck

    Director of Platform

    Mar 2021 - Sep 2022

    Where top tech talent goes to explore what’s next.

  • Oak National Academy

    Oak National Academy

    Head of Engineering

    Mar 2020 - Mar 2021

    When COVID hit, I helped build a platform to support 4.5M children per month to continue learning online.

  • ING Bank

    ING Bank

    Venture Builder

    Aug 2018 - Apr 2020

    A pioneer in digital banking for retail and wholesale clients, driving innovation and sustainability initiatives.

  • Rainmaking


    Venture Builder

    Sep 2016 - Aug 2018

    We unleash the power of entrepreneurship to solve big problems with the world’s leading companies.


    Founder and Chief Technology Officer

    Jan 2013 - Jan 2015

    Startup studio building and testing digital products on repeat

  • Aframe


    Technical Co-founder

    Mar 2009 - Mar 2012

    Co-founded a media collaboration platform startup which raised over $15m of investment.

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