Lead Software Engineer

We’re looking for a Lead Software Engineer to join one of our product teams and provide strong technical leadership.

This role is ideal for someone who enjoys solving complex problems, owning technical direction within a domain, and helping other engineers grow through mentorship and example. You’ll play a key role in shaping how we design, build, and evolve our systems, while working closely with Product, Design, and other engineering leaders.

You won’t be responsible for line management, but you will be expected to set direction, raise standards, and take ownership of the technical outcomes for your area.

About the Team:

Our engineering teams are remote-first, cross-functional product teams, made up of engineers with different specialisms working closely with Product Managers, Designers and stakeholders across the business.

We focus on delivering value iteratively while maintaining a high bar for quality, security and reliability. Our ways of working continue to evolve - blending elements of Scrum, Shape Up and continuous delivery and we expect senior engineers to actively influence and improve how we operate.

As a Lead Software Engineer, you will:

• Provide technical leadership within your team and domain, guiding design decisions and architectural direction.

• Design, build and deliver complex features and systems that are secure, scalable and maintainable.

• Own technical outcomes end-to-end, from discovery and design through to delivery and long-term operation.

• Mentor and coach engineers across the team, supporting their technical growth and confidence.

• Set a high bar for code quality, testing, observability and operational excellence.

• Collaborate closely with Product and Design to shape solutions, challenge assumptions and manage trade-offs.

• Lead technical discussions, reviews and incident investigations, helping the team learn and improve.

• Contribute to wider engineering initiatives and influence standards across the technology organisation.

We’d love to hear from you if:

• You have significant experience building and operating production software in a modern engineering environment.

• You’ve led technical design and delivery for complex systems or domains.

• You’re comfortable working across backend and/or frontend systems (for example Go, TypeScript, JavaScript, Python).

• You have strong knowledge of APIs, data modelling, testing strategies and system design.

• You enjoy mentoring other engineers and leading through influence rather than authority.

• You can communicate complex technical ideas clearly to both technical and non-technical stakeholders.

• You’re comfortable working in a fast-moving, regulated environment where quality and trust are critical

Studies show that women and people from underrepresented backgrounds are less likely to apply unless they meet every requirement. If you don’t tick every box but feel this role could be a great fit, we’d still love to hear from you.

We use and teach:

• We’re passionate about supporting your growth and giving you opportunities to work across the stack. Depending on the team, you’ll work with and help shape:

• Go for backend services

• TypeScript and React for web applications

• React Native for mobile applications

• Temporal for workflow orchestration

• PostgreSQL for relational data

• GCP for infrastructure, monitoring and analytics

Life at Thirdfort:

• Driven by our values, our culture promotes a collaborative and open environment where Thirdforters can take ownership, have impact, and feel empowered when it comes to their growth and development. We understand the importance of our teams wellbeing and recognise a one-size fits all approach rarely works, that’s why we aim to provide the flexibility individuals need to work in the way that suits them, and their families, best.

Our Benefits

• We’ve created our benefits package to reflect Thirdfort’s mission and values. We place a strong focus on Security first given what we do, extending this to our team’s physical, mental and financial security to support them through their big life moments. Our benefits exist to empower our team, ensuring they feel supported and able to work in the way that enables them to do their best work.

When you join Thirdfort, you’ll get immediate access to our flexible employee benefits package that aims to support you across these areas:

• Compensation - £90k - £110k p.a. base salary

• Flexible Working Hours

• Enhanced parental leave

• Work from home allowance

• Uncapped annual leave

• Enhanced sick leave

• Private healthcare with our provider, AXA

• Regular company and team socials

• Uncapped budget for personal development

• Share options for all UK employees

• Customisable wellness budget and discounts on well-known brands with our partner ThanksBen