Callum Denby

Lead JS Developer

London, UK


  • Lead Front End Engineer



    Nov 2019 - Jan 2021

    Upgrading CI/CD pipeline to allow automated and reliable continuous delivery on all front-end surfaces

    Manage delivery of projects from start to finish, shipping major features to the platform

    Creating spikes regarding the implementation of micro-frontends and graphql within our existing ecosystem

    Undertaking the improvement of A11Y issues, allowing the application to be used by screen-readers and keyboard only navigation

  • Senior Software Engineer

    The Economist


    Oct 2018 - Nov 2019

    Creating Node.js Lambda services to handle offer validation for the e-commerce platform

    Use AWS CDK and Node.js Lambda services to build integrations from a third party CMS to existing Economist infrastructure

  • Senior Kafka Engineer

    Eurostar Ltd


    Jul 2018 - Oct 2018

    Create services to integrate Apache Kafka into existing microservice architecture allowing an event driven data flow.

    Lead introduction of machine learning and data analysis utilising Apache Spark via Python with Apache Kafka Streams

  • React Consultant



    Apr 2018 - Jul 2018

    Built React Native prototype in 4 weeks, mirroring 1.5 years of native development.

    Initialized multiple Next.js, React, Redux, Redux Sagas and TypeScript applications for teams to build on top of.

    Ran React workshops for other developers to learn React and enhance their JavaScript skills.

  • Lead Front End Developer

    Square Enix Limited

    London, UK

    Nov 2017 - Mar 2018

    Architect a shared central service for translations.
    Created an offline-first React and Redux isomorphic web app for offline usage.
    Created various SSR Next.js applications for data display and manipulation.

  • Tech Lead

    Arcadia Group Limited

    London, UK

    Mar 2017 - Nov 2017

    Led the development of the React and Redux micro front-end CMS renderer that handled content display for all of Arcadia's brands.
    Created and maintained a modularised component library.
    Created a serverless architecture for serving the micro front-end and exposing a server API.
    Built a React Native cross-platform mobile application for booking meeting rooms.

  • Full Stack Developer


    Leatherhead, UK

    Nov 2016 - Mar 2017

    Converted legacy client project up to modern standards, utilising React, Babel and Axios

  • Full Stack Developer

    BusinessHub Systems Limited

    Hopton, UK

    Mar 2016 - Nov 2016

    Full Stack Development of a Meteor application with a React frontend and Node.js backend.

    Serverless architecture to process and manage RabbitMQ queues.

  • Director

    Jarva Tech

    Mar 2018 - Present


  • JavaScript
  • ESNext
  • React
  • Node.js
  • Meteor
  • Serverless Architecture
  • Elixir
  • React Native
  • CSS
  • Redux
  • Glamorous
  • Electron
  • Git
  • GraphQL
  • Apollo
  • Redux Sagas
  • Redux Observable
  • RxJS
  • Next.js
  • React Static
  • TypeScript
  • Flow
  • Mongodb