Stef Lewandowski

London, UK

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

Work

Experience

  • Pre-launch conversational AI startup

    Pre-launch conversational AI startup

    Fractional Applied AI CTO / Lead Engineer

    Jan 2025 - Apr 2025

    Fractional advisory for a pre-launch early stage conversational AI startup - featuring real-time transcription, live response generation by an assistant during conversation.

  • Aila - Oak National Academy

    Aila - Oak National Academy

    Fractional Applied AI Engineer

    Jan 2024 - Apr 2025

    Helped develop one of the first publicly released generative AI tools via the UK government. An AI assistant to help teachers develop resources to use in their lessons, based on an open API and database of content developed by Oak National Academy.

  • 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

    Rainmaking

    Venture Builder

    Sep 2016 - Aug 2018

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

  • Makeshift.io

    Makeshift.io

    Founder and Chief Technology Officer

    Jan 2013 - Jan 2015

    Startup studio building and testing digital products on repeat

  • Aframe

    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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