Lead Performance Engineer

Leadership, Strategy & Client Engagement:

• Act as a performance engineering consultant for key clients, building strong relationships with internal and external stakeholders, providing expert guidance, and confidently leading technical discussions to non-technical audiences.
• Champion the value of performance engineering across the business, demonstrating its impact on user experience, conversion, and client ROI.
• Mentor and guide junior to mid-level engineers, fostering a culture of performance excellence and continuous learning.
• Contribute to and implement wider performance engineering strategies, evolving practices, and tooling (e.g., K6, Playwright, APM tools).
• Demonstrate strong AI literacy, with practical experience using generative AI (e.g., LLMs, code-gen tools) as a productivity multiplier for tasks such as script/data generation and analysis. Drive innovation in Performance Monitoring and Testing using AI.
• Collaborate with account and leadership teams to identify opportunities and contribute to commercial proposals.

Hands-on & Release Activities:

• Lead performance testing efforts, including workload modeling, test execution, root cause analysis, and reporting.
• Develop and present clear, actionable reports on key performance metrics (including Core Web Vitals) to both technical and business stakeholders.
• Own the configuration and maintenance of APM and observability tools (e.g., New Relic, DataDog, Dynatrace), including designing meaningful dashboards and robust alerting strategies, as dedicated observability engineers are not always present.
• Act as the performance authority within development teams, providing expertise and oversight, particularly regarding the impact of changes on analytics and sales revenue.
• Drive the agenda for performance optimization, introducing new testing capabilities within allocated projects.

Alongside the opportunity to work with some of the most exciting brands around the world, we’ll also prioritise your career development and help you grow your skills. We’ll empower you to make a difference, allow you to be yourself, and respect who you are.

Technical Expertise:

• Programming: Strong proficiency in JavaScript/TypeScript is critical for new development in K6; additional languages (e.g., Python, Java) are a plus.
• Performance Tooling: Deep, practical expertise with APM/RUM tools like New Relic (our primary tool), DataDog, AppDynamics, or Dynatrace. Strong hands-on proficiency with modern load testing tools, specifically K6 and Playwright; experience with JMeter and Locust is also valuable. Experience with K6 browser testing is a significant advantage.
• Cloud Platform Experience: Demonstrable experience on major cloud platforms (e.g., AWS, GCP, Azure).
• Web Technologies: Solid experience with front-end performance analysis (Core Web Vitals) and a strong grasp of platforms and architectural concepts (e.g., Next.js, Magento, SAP Hybris, Shopify).
• Analytical Skills: Strong analytical and problem-solving skills, with an understanding of concepts like parameterization in performance testing.

Leadership & Soft Skills:

• Communication: Exceptional communication skills with the ability to curate the right level of content for different audiences, from developers to senior leadership.
• Growth Mindset: A proactive, self-starting attitude with the drive to push boundaries and champion best practices. You remain cool and collected under pressure, can handle constructive feedback, and have a keen awareness of emerging technologies.
• Mentorship & Collaboration: A passion for mentoring with proven experience guiding less experienced engineers. You share knowledge proactively, collaborate across disciplines, and advocate for integrating performance early in the SDLC.
• Strategic Thinking: Ability to connect dots between complex business challenges and technical solutions, collaborating with architects and other subject matter experts to drive results, moving beyond a siloed approach.

Consultancy & Business Acumen:

• Client Leadership: An assertive and confident approach to client engagement, with the ability to act as a trusted advisor and stand your ground effectively on large, complex projects.
• Commercial Mindset: Strong commercial acumen, comfortable discussing business drivers like cost and ROI, and an eagerness to contribute to business development activities.

If you know some of this, even better:

• Deeper eCommerce Expertise: Proven experience in performance testing and analysis of e-commerce applications, preferably with platforms like IBM WebSphere Commerce, SAP Hybris, or Magento, or SFCC Sports.
• Broader Stack Exposure: Experience with SRE practices, caching/CDNs, containerisation (Docker/Kubernetes), or infrastructure-as-code (e.g., Terraform) from a performance perspective.
• Continuous Delivery Integration: Experience implementing performance testing and performance gates in CI/CD pipelines, including test automation, environment strategy, and integration with observability tooling.
• Formal Line Management Experience: Experience managing one or more team members with accountability for professional development, performance management, and day-to-day well-being.
• Frontend Performance Analysis: Experience with front-end page load analysis, profiling, and optimization using tools like WebPageTest, PageSpeed Insights, SpeedCurve, or sitespeed.io.