Kieran Allen

Frontend Developer

London, United Kingdom


I've been working as a frontend developer for a number of years now, and in that time I've become skilled in a number of different technologies. I have a strong foundation in JavaScript, and I'm also experienced with ReactJS, Redux, ReactQuery, TailwindsCSS and NextJS. I'm always looking to improve my skills and learn new technologies, so that I can provide the best possible experience for my users. Outside of work, I enjoy cycling and playing video games. I am very interested in the potential that cryptocurrencies have to change the way that we think about money and finance.

Senior Frontend Developer - Ledger

May 2023 - Present

  • As part of a team developing live apps that interact with the Ledger Live Hub, I play a key role in building and enhancing the user experience for Ledger's crypto hardware wallet customers.
  • Developed a create-live-app repository that can be used by other Ledger teams or external parties to bootstrap their own live app. This repository includes documentation and best practices, enabling faster and more efficient development of new live apps while maintaining consistency and quality across the ecosystem.
  • Took ownership of managing the firefighting process within the frontend team. This involved documenting best practices, establishing processes for identifying and addressing critical issues, and coordinating with team members to ensure timely resolution of problems. By streamlining the firefighting process, I have contributed to improved stability and reliability of the frontend applications.
  • My team and I are currently working on a new version of the swap feature, with the goal of simplifying the integration of future partners and accelerating the rate at which the swap team can release frontend features and fixes. This initiative aims to improve the overall user experience and provide a more seamless and efficient process for customers.
  • I contribute to the development and implementation of best practices, ensuring that the frontend codebase is maintainable, scalable, and adheres to industry standards. This helps to facilitate collaboration among team members and enables the efficient delivery of high-quality features and bug fixes.
  • Developed a testing tool that leveraged Foundry and Anvil to enable fork testing within the Ledger Live app. This tool allowed developers to mock ETH and ERC20 balances and transactions, eliminating the need to request funds manually and significantly speeding up development time.

Frontend Developer - Truelayer

September 2021 - Present

  • I was responsible for the design and implementation of the hosted-payments-page, which has resulted in a significant increase in transactions. The page is now used by 2000+ customers daily, which has had a positive impact on the companys bottom line. In addition, the page has been well-received by customers, with many positive reviews.
  • I worked on the truelayer-embedded-payment-page which makes it easy for customers to integrate an open banking payments flow into their website. The SDK handles all the necessary authentication and authorization, so all the customer needs to do is integrate the SDK into their website and add a few lines of code to enable the open banking payments flow.
  • I worked on integrating MSW into the Truelayer hosted payments page project. This made testing easier and Frontend development quicker when reliant on backend changes.

Frontend Developer - OVO Energy

April 2018 - September 2021

As a Frontend Developer at OVO Energy I work as part of a team to acquire new customers and retain current customers through our Acquisition and Renewal flows. I work primarily with AngularJS and ReactJS, both of which leverage the TypeScript library in order to create safer code.

Some projects I have worked on include:

  • Migration of the OVO acquisition frontend from AngularJS to ReactJS.
    • 73% decrease in time to interactive.
    • 36% reduction in Javascript package size.
    • 98% reduction in css package size.
  • Migration of team applications to a new AWS account.
    • Terraforming frontend application Infrastructure
    • Migration to CircleCI as application build pipeline ( away from GoCD )
  • Implementation of new renewal frontend designs
    • 10% increase in number of customers renewing their plans.

UI Developer - Playtech

September 2016 - April 2018

As a UI Developer at Playtech I work extensively with data heavy customer facing React.JS applications. My team follow the scrum methodology with week long sprints and daily stand-up meetings to inform others on work done. As part of my team I carry out daily code reviews to ensure quality of code across all applications is maintained.

Some projects I have worked on:

  • Implemented localised date and number formatting for clients using the react-intl library. This feature greatly improved the user experience for clients located outside the United Kingdom.
  • Developed a native fetch component to handle all of the applications api requests, thus removing any need for JQuery in our build.
  • Successfully reworked our redux store to be used across all applications instead of using separate stores for each application. This greatly simplified our codebase and cut down on a lot of duplicate code.

Education - University College Cork

September 2011 - June 2016

BSc Computer Science