Lead Software Engineer at Thirdfort

Picture a small, focused group of engineers, designers and product thinkers who spend their days making sure the biggest financial moments in people’s lives stay safe. We built Thirdfort because a friend lost £25,000 buying their first home and no tool existed to stop it. Today more than 1,500 regulated businesses rely on our platform to run secure identity checks, open-banking transfers and facial-verification flows, and we’ve raised over $33 million from investors who believe fraud prevention should be simple, private and fast.

The opportunity

We’re inviting a Lead Software Engineer to join one of our remote-first product teams. In this role you will set the technical direction for a meaningful slice of our platform, guide architectural choices, and help the engineers around you grow. You won’t manage people directly, yet your influence will shape how we design, test and operate the services that protect millions of transactions every year.

A day in the life

• You might start the morning reviewing a pull request that introduces a new Temporal workflow for handling complex verification steps, then pair with a mid-level engineer to refine the data model so it stays clear as the feature scales.
• After a quick sync with Product and Design you could sketch the API contracts for a React Native screen that lets estate agents capture documents on the move, weighing security, latency and user-experience trade-offs before any code is written.
• In the afternoon you might dig into an observability alert on our GCP dashboards, lead a blameless incident review, and leave the team with clearer run-books and a short proposal for improving test coverage across the Go services.

Who you are

You bring several years of hands-on experience designing and running production systems in a modern engineering environment. You have led the technical design and delivery of complex domains, and you move comfortably across backend and frontend stacks-Go, TypeScript, React or React Native are all familiar territory. Strong opinions on API design, data modelling, testing strategies and system reliability guide your decisions, yet you communicate those ideas clearly to colleagues who are not engineers. Mentoring comes naturally; you enjoy raising the bar for the whole team without needing formal authority. Working in a regulated space where trust and quality are non-negotiable feels like an interesting challenge rather than a constraint.

Why you'll love it here

We offer a base salary of £90,000 along with share options for every UK employee. Your working hours stay flexible, and you receive a work-from-home allowance so your remote setup always feels comfortable. Time away is generous: uncapped annual leave, enhanced sick leave and enhanced parental leave mean you can step back when life demands it. Private healthcare through AXA, a customisable wellness budget with ThanksBen discounts, and an uncapped personal-development fund keep you healthy and growing. Regular company and team socials-virtual or in person-help us stay connected while we solve hard problems together.