Senior Backend & Infrastructure Engineer - Global Big 4

(12-Month Contract) – Global Request Gateway

Location: London, UK (5 days onsite)Duration: 12-Month Contract + Ext/Perm

The Reality of This Role:

Let’s be entirely transparent from day one: this is not a standard feature-building job. If your background is a broad but shallow mix of building user-facing web apps and clicking buttons in the AWS console, this will not be the right fit.

We are hiring a contract L5 Software Development Engineer to join the Gateway team. This team doesn’t build the visible screens; they build the globally distributed, high-throughput pipes that sit between the internet and the Video servers. Every single time a user clicks "Play" anywhere on Earth, their request hits your infrastructure first.We need an engineer with profound backend depth, sharp system design instincts, and an operational mindset who wants to operate at a higher level of abstraction.

What You’ll Actually Do

• Own the Edge: Design, build, and deploy backend services and native AWS infrastructure handling massive global throughput (high TPS) across multiple AWS regions.
• Architect for Scale: Take ownership of authentication, DNS/network routing, edge caching, and security/availability protections at the network edge.
• Drive Operational Excellence: This isn't just about shipping code and walking away. You will tune alarms, build dashboards, manage runbooks, and participate in high-stakes on-call rotations to ensure continuous reliability.
• Leverage Next-Gen Tooling: The team heavily utilizes internal AI agents (Clause, OpenAI, Amazon's Kiro wrapper) for rapid operations, scaffolding, and debugging. You will review AI-generated logic with a highly critical, human-in-the-loop eye to maintain absolute availability.

The Technical Bar We Are Looking For

We are testing heavily for deep infrastructure and distributed system design knowledge.

To clear the bar, you need:

• Production Code Depth: Deep, hands-on proficiency in Java and TypeScript. You must understand concurrency, performance optimization, and low-latency execution.
• Infrastructure-as-Code Mastery: You don't build infrastructure manually. You must have extensive experience provisioning infrastructure natively via AWS CDK.
• Core Cloud Stack: Real-world experience engineering with EC2, NLB, Lambda, DynamoDB, and ElastiCache.
• Solid Networking Fundamentals: You need a fundamental grasp of how the internet moves data—specifically DNS, HTTP/TLS termination, and complex load balancing.
• L5 Autonomy: You are comfortable stepping straight into an ambiguous problem space, driving technical design trade-offs independently, and verifying systems meticulously.

Why Apply?

This is a high-impact, 12-month contract joining a collaborative, 9-engineer team running one of the highest-scale entry points in the streaming industry.

If you want to put true, massive-scale systems engineering on your CV and work with state-of-the-art AI-assisted workflows, this is the project.