Senior Engineer (IC3)
Full-time: Hybrid
Manchester or London
Up to £100,000 per annum D.O.E

As a Senior Engineer (IC3) at Lunio, you lead the design and delivery of complex, cross-service features on our ad-fraud prevention platform. You set a high bar for engineering quality by example. You make pragmatic architectural choices, and help others navigate ambiguity. You operate the services you build, improve reliability and performance, and mentor teammates so the whole squad ships value predictably. You implement and deliver working solutions on an ongoing basis.

Key Responsibilities

• Lead complex delivery: shape scope and architecture for cross-service features/platform work, break down ambiguity, coordinate across Product/Design/Data to land outcomes.

• Raise the quality bar: define practical standards for testing, security, and observability, act as approver on critical PRs, model excellent reviews and pairing.

• Operate and improve production: own service performance targets for your area, lead incident response, drive corrective actions to completion, and reduce recurrence.

• Grow others: mentor and unblock teammates, transfer knowledge through pairing, docs, and structured feedback.

• Shape team practices & roadmap: contribute to technical strategy and sequencing, surface trade-offs and risks early, champion incremental delivery.

• Service Ownership: own the full software development lifecycle not only for your changes, but for all changes that affect a Service you have worked on, by monitoring PRs and success metrics for your services

What makes a great Senior Engineer at Lunio?

Software Design & Architecture: Designs evolvable systems with clear boundaries and data ownership, anticipates failure modes and keeps solutions simple.

Technical Execution & Delivery: Leads execution across multiple stories/engineers, breaks down ambiguous problems, delivers predictably with sensible trade-offs.

Testing, Reliability & Observability: Bakes in testability, defines/uses service performance targets, alerts, logs, and traces, advocates for reliability alongside features.

Security & Privacy: Applies secure-by-default patterns, reviews dependencies/risks, and addresses vulnerabilities within the team’s domain.

Collaboration & Communication: Facilitates decisions, aligns stakeholders, and records them via concise docs others can follow.

If you think you've got what it takes to be the next Senior Engineer at Lunio we can't wait to hear from you and have you join our journey!

Apply below by attaching your CV & answering the 3 screening questions 🚀🔥

💡Application Guidance💡

Before you hit apply…

We've ditched the traditional cover letter (you're welcome) and replaced it with three short questions. Think of them as your chance to show us who you are beyond your CV: no fluff, no filler, just the good stuff.

Please ensure that you answer all 3 questions. We genuinely read every answer, but we can only review applications where all three are completed.

Now, here's the slightly ironic bit; we're a company that champions AI every single day, but for this part of the process, we'd love you to leave it on the bench. These questions are about getting to know you, your thinking, your experiences, your voice. AI can't do that justice.