Staff Platform Site Reliability Engineer in London

At Index Exchange, we're reinventing how digital advertising works—at scale. As a global advertising supply-side platform, we empower the world's leading media owners and marketers to thrive in a programmatic, privacy-first ecosystem. Our proprietary tech is trusted by some of the world's largest brands and media owners and plays a crucial role in keeping the internet open, accessible, and largely free. We process more than 700 billion real-time auctions every day with ultra-low latency. Our platform is vertically integrated from servers to networks and runs primarily on our own metal and cloud infrastructure. This end-to-end infrastructure is designed to provide both stability and agility, enabling us to adapt quickly as the market evolves. At the core of it all is our engineering-first culture.

Our engineers tackle internet-scale problems across tight-knit, global teams. From moving petabytes of data and optimizing with AI to making real-time infrastructure decisions, Indexers have the agency and influence to shape the future of advertising. We move fast, build thoughtfully, and stay grounded in our core values.

The Role: Cloud Platform Engineering builds the platform that makes all of this possible. We architect and deliver the foundational infrastructure—Kubernetes clusters, deployment pipelines, infrastructure-as-code frameworks, container platforms, storage systems—and the software layer on top of it: standard libraries, internal SDKs, platform APIs, and the interfaces that every engineering team at Index Exchange builds on top of. Platform engineering here is software engineering. We don't operate day-to-day; our operational counterpart, Systems Engineering, carries that load. We stay focused on what moves the needle: designing and building systems at scale.

As a Staff Platform Engineer, you will own architectural decisions, deliver large-scale infrastructure projects, and shape the technical direction of a platform that processes more real-time transactions than almost any system on earth. The vision: We build, scale, and maintain Index Cloud—a multi-tenant, globally distributed compute platform that serves both our exchange workloads and the workloads of every partner in our ecosystem. This is not incremental improvement. It's building a platform-as-a-product at internet scale.

What You'll Work On:

• Build the platform, not run it. You'll design and deliver multi-tenant Kubernetes infrastructure across bare-metal and public cloud, build infrastructure-as-code frameworks that push changes across thousands of servers, and write the standard libraries, SDKs, and platform APIs that every engineering team at Index Exchange depends on.
• Solve hard distributed systems problems. Real-time bidding with sub-millisecond overhead. Multi-datacenter consistency. Deploying safely to a fleet of thousands. Load balancing at a scale where the easy approaches don't work.
• Own the architecture. You'll drive technical direction through RFCs and design reviews, set standards for shared platform domains, and make the calls on tooling, security posture, and system design.
• Make engineers faster. Build golden paths, self-service tooling, and platform APIs that let engineering teams ship without friction.
• Mentor and raise the bar. Coach engineers, foster a culture of engineering excellence, and collaborate across Cloud Platform Operations, SRE, Network, Security, and Software Engineering teams.

What You Bring:

• 8+ years in platform engineering, SRE, infrastructure engineering, or DevOps.
• Deep experience with Linux internals: kernel tuning, network stack, system observability, security.
• Strong Kubernetes expertise: cluster lifecycle, networking, storage, RBAC, multi-cluster—across bare-metal and cloud (EKS, GKE).
• Infrastructure-as-code at scale: Terraform, Ansible, GitOps (ArgoCD or similar).
• Proficiency in Go, Python, or both—for building libraries, SDKs, and platform APIs, not just scripts.
• Solid networking fundamentals (L2-L7), load balancing, DNS, service discovery.
• A track record of driving technical strategy across teams—not just executing within one.

Valuable Experience:

• Distributed storage systems (e.g. Ceph)
• Big data infrastructure: Hadoop, Spark, HBase, Kafka.
• Observability stack design: Prometheus, Grafana, ELK, Mimir, Loki, Tempo.
• Secrets management (Vault), certificate management, access control at scale.
• Hybrid cloud architectures: federating public cloud (AWS, GCP) with on-premises environments.
• Experience with bare-metal infrastructure in globally distributed data centers.

Who Thrives Here: We don't care whether you call yourself a platform engineer, an SRE, a DevOps engineer, or a systems engineer. We care that you're passionate about technology, that you get excited by hard problems at scale, and that you can communicate and collaborate as well as you can code.

Why you'll love working here:

• Comprehensive health, dental, and vision plans for you and your dependents.
• Paid time off, health days, and personal obligation days plus flexible work schedules.
• Competitive retirement matching plans.
• Equity packages.
• Generous parental leave available to birthing, non-birthing, and adoptive parents.
• Annual well-being allowance plus fitness discounts and group wellness activities.
• Commuter benefits and discounts, where available.
• Employee assistance program.
• Mental health first aid program that provides an in-the-moment point of contact and reassurance.
• One day of volunteer time off per year and a donation-matching program.
• Monthly town halls and regular community-led team events.
• Multiple resources and programming to support continuous learning.
• A workplace that supports a diverse, equitable, and inclusive environment.

Equal employment opportunity: At Index Exchange, we believe that successful products are built by teams just as diverse as the audience who uses them. As such, we are committed to equal employment opportunities. We celebrate diversity of race, color, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender identity or expression, or veteran status.

Accessibility for applicants with disabilities: Index Exchange welcomes and encourages individuals with disabilities to apply to work with us. If you require an accommodation, please share the details of your request and any information how we can assist you with the hiring recruiter when they contact you. Index Exchange will make reasonable efforts to ensure accommodation requests are met throughout the recruitment process.

Index everywhere, Index anywhere: Our corporate headquarters are in Toronto, with major offices in New York, Montreal, Kitchener, London, San Francisco, and many other global cities. As a major global advertising exchange, we are committed to operating as a tightly knit global team and embracing and empowering talent wherever our colleagues may be.