Senior Software Engineer - k6 Core | United Kingdom | Remote

Grafana Labs, the company behind the open observability cloud, is founded on the principles of open source, open standards, open ecosystems, and open culture. Grafana Cloud, our fully managed observability platform, is flexible and built for scale. With Grafana Cloud's actually useful AI, organizations can see, understand, and act on all their disparate data to move at the speed of their ambitions. Today, more than 35 million users and 7,000+ customers trust Grafana Labs to ensure reliability of their applications and systems, resolve incidents quickly, and optimize their telemetry to reduce noise and cost.

We are a 100% remote company with 1,600+ team members across 40+ countries. Our team thrives in an innovation-driven environment where transparency, autonomy, and trust fuel everything we do. You may not meet every requirement, and that’s okay. If this role excites you, we’d love you to raise your hand for what could be a truly career-defining opportunity.

The Opportunity: At k6, we build reliability and performance testing tools for developers and QA engineers. Grafana k6 is an open-source project focused on making performance testing practical, approachable, and useful in real-world engineering workflows. We care deeply about developer experience, correctness, and scalability.

What You’ll Be Doing: You will join a team of engineers responsible for building and maintaining k6, a performance testing tool written in Go. The team also maintains the open-source project, which means working directly on the product, the codebase, and with the community using it. In this role, you will work on features and improvements across the k6 codebase, from initial idea through implementation and delivery. Much of the work involves problems that are not fully specified up front and require understanding the context, evaluating trade-offs, and choosing a reasonable technical approach. You will work with a high degree of independence while collaborating closely with other engineers on design, implementation, and code reviews. You are expected to deliver production-quality code, maintain existing functionality, and help keep the system reliable and maintainable over time.

Some work may involve the k6 cloud offering, which builds on top of k6 to run distributed tests across data centers worldwide. This includes Go services that support distributed execution and require careful attention to performance, correctness, and failure modes. Because the team is small, your work will have a direct and visible impact on the product and its users. You will work alongside experienced engineers in an environment that values clarity, pragmatism, and sound engineering judgment.

What Makes You a Great Fit: We start with problems, not prescriptions. Engineers are expected to understand the constraints, propose a pragmatic design, and carry the work through to delivery. We move deliberately and release on a regular cadence of roughly every six weeks. Between releases, we focus on small, safe, incremental changes. Work is asynchronous by default, with decisions captured in pull requests and short design notes. Meetings are used for alignment rather than status updates. Code reviews focus on correctness, long-term maintainability, and user impact. When trade-offs are required, we aim to make them explicit and reversible. The team owns the product end to end, including architecture, releases, user-facing behavior, and the health of the open-source project.

We’re looking for an experienced engineer with strong programming skills and a track record of working on non-trivial systems. You should have:

• Strong experience building production software in Go, or another language with good support for concurrency and parallelism
• Experience working on larger or long-lived codebases
• The ability to work independently on scoped problems and deliver them to completion
• Clear technical communication skills, especially in code reviews and design discussions
• A good understanding of internet protocols such as HTTP, gRPC, and WebSockets, with some familiarity with lower-level networking concepts
• Experience with modern development practices, including testing, code review, and iterative development

Bonus Points For: You do not need experience with everything listed below. These are areas where familiarity is useful for the role, and the more you bring, the easier the ramp-up will be:

• Contributing to or maintaining open-source projects
• Prior experience using k6 in production, or contributing to the k6 project or ecosystem
• Performance, reliability, or network testing and optimization
• Distributed systems or cloud-based services
• JavaScript and/or TypeScript
• Backend systems for web or mobile applications
• Tools and platforms such as Docker, AWS, microservices architectures, and observability tools like Grafana or APM systems

Compensation & Rewards: In the United Kingdom, the Base compensation range for this role is GBP 91,755- GBP 110,106. Actual compensation may vary based on level, experience, and skillset as assessed in the interview process. All of our roles include Restricted Stock Units (RSUs), giving every team member ownership in Grafana Labs' success.

Why You’ll Thrive at Grafana Labs:

• 100% Remote, Global Culture
• Scaling Organization
• Transparent Communication
• Innovation-Driven
• Open Source Roots
• Empowered Teams
• Career Growth Pathways
• Approachable Leadership
• Passionate People
• In-Person onboarding
• Balance is Key

Equal Opportunity Employer: Grafana Labs is an equal opportunities employer. We welcome applications from everyone regardless of race, colour, nationality, origin, caste, sex, gender reassignment identity or expression, sexual orientation, age, religion or belief, disability, veteran status, genetic information, pregnancy, maternity, marital, family or carer status, or any other characteristic which is protected by local law.