Senior Software Engineer (Quality Engineering)

Thought Machine's mission is bold – to properly and permanently rid the world's banks of legacy technology. To achieve this, we have developed the foundations of modern banking through core and payments technology which run natively in the cloud. What we are attempting is hard and means we need great people working together to build great technology.

We have grown rapidly in the past few years – growing our team to more than 550 individuals across offices in London, New York, Singapore, Sydney and our newly established Engineering Hub in Lisbon. We have raised more than £500m in funding and our investors include Molten Ventures, Eurazeo, Intesa Sanpaolo, Temasek, Nyca Partners, JPMorgan Chase Strategic Investments, Standard Chartered Ventures, and more.

We have created a culture that enables our team to produce the best work in the industry while ensuring we have fun along the way. We're regularly cited as having a fantastic workplace culture and have been recognised by Sifted magazine as having one of the highest Glassdoor ratings for a UK fintech company and the industry's most generous employee share package. Named one of the world's most innovative fintechs by Global Finance Magazine, we were also recognised by the Financial Times as one of Europe's fastest-growing companies for two consecutive years—and a UK Best Employer for 2026.

Senior Software Engineer in Quality Engineering

Thought Machine is building the backbone of critical banking infrastructure worldwide, empowering the world’s largest financial institutions to modernise their operations. In this high-stakes environment, producing quality software isn't just a best practice, it is a fundamental imperative and the foundation of our clients' trust. We invest heavily in our testing architecture because the reliability of our software is critical to the global financial ecosystem.

We are seeking a Senior Software Engineer to drive quality engineering excellence, modern testing architecture and practices, and scalable infrastructure across our product engineering organisation.

This is a rigorous, hands-on backend software engineering position, not a traditional QA or SDET role. We do not believe in siloed testing teams; instead, we believe in building intelligent, automated infrastructure and AI-driven developer tooling that make high-quality delivery the default.

Why Join Us?

In this role, you will have the unique opportunity to solve complex challenges at a massive scale, directly impacting the velocity of our engineering teams and the stability of global banks. We want engineers to be at the forefront of transforming our testing platforms from an internal utility into a powerful commercial asset. By providing total transparency into how we test, deepening our collaboration with clients, and exposing these capabilities externally via managed offerings like "Testing as a Service" (TaaS), you will fundamentally shift how the industry perceives software quality.

You will work at the cutting edge of infrastructure and AI, honing your skills in building agentic tooling, advanced observability pipelines, and cloud-native platforms. This is a chance to elevate your career by architecting platforms that developers love and clients trust, all while shaping the engineering culture of a hyper-growth tech company.

You will partner closely with engineering leadership, product management, and developer platform teams to design, architect, and implement industry-leading testing infrastructure. You will act as a technical leader championing testability, observability, and engineering best practices across the entire development lifecycle for all of our products.

The Mentality We Are Looking For

We value engineers who combine rigorous technical craft with ownership, continuous learning, and a relentless focus on high-quality delivery.

"Toil is a Defect" Mindset: You view manual testing and complex debugging not as a necessity, but as a platform defect to be automated away using intelligent tooling and AI.

Guardrails, Not Gates: You believe in empowering developers with speed and observability, using quantitative metrics and automated telemetry to inform risk-based decisions rather than relying on bureaucratic red tape.

Technical Ownership & Excellence: You take pride in end-to-end delivery, from architectural design and coding to automated testing, performance optimization, and operational monitoring.

Collaborative Technical Leadership: You enjoy partnering with software engineers, product managers, and client-facing teams to elevate testing standards and foster a transparent culture of quality.

Duties

Enablement & AI Tooling: Design, build, research, evaluate and adopt advanced engineering tools, including leveraging Agentic AI for the automated triage of performance test failures, automated test-code generation, and eliminating developer toil.

Governance & Observability: Develop and integrate quantitative product reliability metrics for test coverage, execution speed and defect prevention, into CI/CD pipelines. Build telemetry and infrastructure for advanced testing paradigms, including deterministic fault injection to catch concurrency and race conditions.

Drive Quality Engineering Initiatives: Partner with engineering teams to conduct risk analyses, implement integration and performance testing strategies, and resolve complex edge-case defects.

Backend Engineering Delivery: Develop high-quality, testable, and robust backend services, APIs, and microservices in alignment with architecture standards.

Technical Mentorship: Mentor junior and mid-level engineers in test automation patterns, backend engineering design, unit/integration testing strategies, and code hygiene.

Requirements

Extensive hands-on experience in backend software development using modern languages (e.g., Go, Python) and cloud-native architecture.

Proven track record of designing and implementing scalable backend platforms, with deep expertise in CI/CD integration, containerisation, and orchestration (e.g., GitHub Actions, GitLab CI, Docker, Kubernetes).

Deep understanding of complex distributed systems, API protocols (REST/gRPC), and observability stacks (e.g., Prometheus, Grafana, BigQuery).

Familiarity with leveraging modern AI-assisted tools and building agentic workflows for code generation, log analysis, and automated triage.

Excellent communication and stakeholder management skills to advocate for quality initiatives and influence cross-functional technical teams.

If you are passionate about building robust backend infrastructure, advancing quality engineering architecture, and leading software excellence, we want to hear from you.

Benefits

Highly competitive salary

Pension plan (match up to 5%)

Life insurance - three times annual salary

Competitive maternity (six months fully paid) and paternity leave (four weeks fully paid)

Shared parental leave (matched to our maternity leave for the same point in time)

25 days holiday and bank holidays

Flexible working hours

Cycle-to-work scheme

Electric car scheme

Season ticket loan

Access to outstanding learning materials and courses

Sports and hobby clubs, subsidised by Thought Machine

All the latest tech you need

Start the day properly with fresh fruit and cereals

Huge range of healthy (and not-so-healthy) snacks, smoothies and drinks

A talented and experienced team as your colleagues

An environment where we encourage learning and progress

Two charity days a year

Weekly food pop-up

We actively hire candidates who demonstrate technical excellence in their field and welcome people of all ages and backgrounds, providing everyone with equal access to professional development. You are encouraged to apply even if your experience doesn't accurately match the job description. We also encourage applications from those with different abilities, including candidates with ADHD, autism,