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About

Higgor Leimig

Engineering Manager and Principal Software Engineer based in London, with 16 years of experience across fintech, payments, and platform engineering. I lead small teams, design distributed systems, and try to write clearly about the work.

Download CV (PDF) ↓

Experience

  1. Engineering Manager

    Jan 2026 – Present

    Runa · London, UK

    • Leading a 4-person engineering team responsible for Fraud Prevention. Delivered features that reduced exposure and increased identification of fraudulent card transactions — cutting successful attacks from £150k to £4k.
    • Defined the framework used by Engineering leadership to understand and discuss Fraud Prevention within the platform, leading to concrete roadmap items to reduce fraud incidence.
    • Owned the team roadmap in lieu of a Product Manager.

  2. Principal Software Engineer

    Mar 2023 – Dec 2025

    Runa · London, UK

    • Technical leader of an Engineering Domain responsible for integration with 100+ suppliers.
    • Facilitated the onboarding and training of two newly established teams at a new company site in Sofia, Bulgaria — bringing them up to speed on the software they inherited as well as company culture and expectations.
    • Led migration away from the company monolith to serverless services, achieving a 97% reduction in API response time in one platform area.
    • Led technical discoveries that cut supplier integration time from 2 weeks to 2 days.

  3. Senior Software Engineer

    Mar 2022 – Mar 2023

    Runa · London, UK

    • Led system redesign that reduced internal manual work by 95% through automation of brand approval decisions.
    • Redesigned and rebuilt a web app serving 1.4M+ users/month, improving developer experience and reliability of a business-critical system.

  4. Software Engineer

    Sep 2019 – Feb 2022

    Klarna · Germany

    • Worked on Klarna's Bank Account core technology — refactoring and improving the Transactions system responsible for giving meaning to ledger entries and reconciliation.
    • Sole developer on an established team for three months — handled on-call responsibilities and viability research for future products.

  5. JavaScript Developer

    Nov 2017 – Aug 2019

    Viasto · Germany

    • Led performance optimisations resulting in a 66% performance increase of the main web application.
    • Rebuilt the company's core product technology in a tight timeframe, improving developer experience and customer satisfaction.

  6. Software Engineer

    Jun 2015 – Nov 2017 & Jun 2010 – Apr 2014

    CESAR · Brazil

    • Technical leader of a 20-person team across 2 sites in Brazil and the US.
    • Led performance improvement efforts delivering a 60%+ boost to a production web application.

Education

  1. MSc Software Engineering

    Aug 2016 – Aug 2018

    CESAR School

    Researched cache schemes in Information-Centric Networks to improve IoT performance. Published IoT Caching in Information Centric Networks at IARIA 2017.

  2. BS Computer Science

    Aug 2011 – Jun 2016

    DeVry Brazil

    Co-created Annuit Walk, an assistive glasses system for vision-impaired people. Winner of the 2014 Youth Award.

  3. Exchange Program

    Jun 2014 – May 2015

    Temple University

    Awarded a competitive scholarship where applications outnumbered spots 16,000:1. Developed P910 in partnership with Temple University Campus Police to improve campus emergency call management.

Skills