Senior QA Engineer Performance & Scalability

What you can expect to be doing: We're looking for a Senior QA Engineer, Performance & Scalability who doesn't wait to be told what to test. You'll own performance and scalability across our platform, 30+ microservices, event-driven flows, and the legacy dependencies that come with a real production system at scale. This isn't a "run a load test before release" role. This is a role where you make performance a first-class concern from day one, where you define the thresholds that decide pass or fail, and where you hold the bar when something is degrading and nobody yet knows why. You'll be the performance voice in every room you walk into, design discussions, architecture reviews, incident retrospectives. When latency spikes, you're already halfway through the trace. When a new service is being scoped, performance is already in the delivery plan because you put it there.

Own Performance from Day One - You embed performance thinking into the delivery plan before code is written, not as an afterthought before release. You make performance testing a natural part of how teams build and ship — not a gate they hit at the end.

Define What Good Looks Like - You own the thresholds, metrics, and SLOs that govern pass or fail. You decide what a breach means, you set the budgets (latency, error rate, throughput), and you make those signals objective enough that a pipeline can act on them without a human reading graphs.

Test Services in Isolation, at Production Scale - You design and build performance tests for individual services, stubbing downstream and third-party dependencies so each journey is tested on its own merits. You map load to real production traffic to find where things bend and where they break.

Lead Performance in CI - You integrate performance testing into CI/CD so regressions are caught automatically, early, and fast. You own the fail-fast signals and keep them trustworthy.

Build Reusable, Scalable Assets - You build performance tests as code, reusable components, templates, and utilities that scale across teams and services. You handle data seeding and test setup so runs are repeatable and realistic.

Diagnose, Don't Just Report - You root‑cause regressions across the stack, reading logs and tracing requests through distributed systems to find the source yourself rather than waiting for someone to hand it to you.

Reach Out and Drive Outcomes - You engage the right stakeholders, engineering, platform, product - to turn findings into fixes. You don't file a report and walk away; you drive the outcome.

Influence Decisions - You raise performance and scalability risks early, challenge assumptions constructively, and bring people with you. When a design won't scale, you say so before it ships.

What we’re looking for:

• 5+ years in performance engineering, with a track record of owning performance across complex, modern systems, not just executing someone else's load test.
• Deep performance testing expertise. Hands‑on experience designing realistic load models, running load, stress, soak and spike tests, and interpreting results meaningfully.
• K6 or similar - You have real, hands‑on depth with k6 for building and running performance tests.
• Monitoring and observability know‑how. You're comfortable with tools like Datadog, Grafana, CloudWatch or similar, and you use them proactively to correlate test results with what the system is actually doing, not just when something is already on fire.
• Strong programming ability. You're extremely strong in at least one language. We use TypeScript across our stack; if your fundamentals are solid in another language, we're confident you'll pick it up fast.
• Microservices and distributed systems. You understand service‑oriented architectures, dependencies, and the realities of testing a service in isolation — stubbing, mocking, contract boundaries, as well as end‑to‑end.
• CI/CD fluency - You've integrated performance testing into CI/CD pipelines and understand how to keep feedback fast and signals reliable.
• Experience with AWS infrastructure is strongly preferred.
• Strong communication and presence. You participate fully in agile ceremonies and cross‑team conversations. You don't sit quietly when something needs to be said.

Nice to Have

• Experience in fintech, wealth management, or regulated financial services.
• Experience using AI‑assisted tooling to accelerate performance work.
• Contributions to internal quality guilds, communities of practice, or engineering culture initiatives.
• Experience mentoring engineers on performance and testing best practices.

What we’re really looking for: Beyond the skills and the experience, we want someone who operates with ownership and independence. You don't wait for permission to improve something. You see a gap in coverage, a flaky test, a missing dashboard — and you fix it. You treat the Wealth Management experience line as yours, and you hold yourself to the same standard you hold the product to. You're not a gatekeeper. You're a quality enabler. And you make every team you work with better at shipping reliable software.

Working Hours

Monday to Thursday: 9:00 AM – 6:00 PM
Friday: 8:00 AM – 4:00 PM (Start your weekend early!)
Enjoy a structured yet balanced workweek, with an early Friday finish to kickstart your weekend!

PERKS

£60,000 - £70,000 per annum
Discretionary Performance-Related Annual Bonus
Workplace pension scheme - We invest in your future with a workplace pension scheme, contributing 5% on earnings up to £50,000. Plan ahead with confidence while you grow your career.