Why This Role ExistsThe Email & Collaboration Security (ECS) product line sits at the intersection of some of the most consequential challenges in enterprise security today: AI augmented threats, sprawling collaboration surfaces, multi cloud delivery complexity, and the expectation that detection and response capabilities keep pace with a threat landscape that does not wait. This architecture is not greenfield. It carries two decades of accumulated product decisions, integration contracts, and operational constraints. The right candidate understands why that history matters before proposing how to move beyond it. Reasoning about legacy shape and evolutionary trajectory simultaneously is not optional; it is the job. The successful candidate will serve as connective tissue across product management, engineering, and the broader Architecture Leadership Team - turning customer and business problems into coherent, deliverable technical direction, and owning the decisions that give ECS engineering teams a stable foundation to move fast with quality.
AI First Ways of WorkingMimecast is an AI first engineering organisation and this is an operating expectation. The person in this role is expected to use AI tools as a genuine, daily part of how they work: for design exploration and iteration, documentation, analysis, prototyping, and research synthesis. This means having a real, practised opinion on where AI tooling accelerates quality decisions and where it introduces risk. It also means designing systems that incorporate AI components thoughtfully: understanding the implications of LLM integration, agent boundaries, prompt and data contract stability, and evaluation coverage for AI driven features. Candidates who treat AI tooling as optional or experimental are not the right fit for this role. The expectation is fluency and daily practice, not passing familiarity.
ECS DomainLead from Problem Space, Not Solution SpaceThe role engages at the problem framing stage, not after requirements have already hardened into tickets. This means facilitating workshops with PMs, UX, and engineers to surface real customer constraints and articulate what good looks like in business and user terms before any technical shape is proposed.
Own Integration Contracts as Product ArtefactsThe durable interfaces - APIs, event contracts, data schemas - that connect ECS capabilities to the broader Mimecast platform are first class artefacts owned by this role. They outlast individual features, and the coordination work that makes integrations actually land across teams and time is part of the remit.
Build the Architectural ContextEngineering Teams Operate Inside ADRs, service interaction patterns, NFR targets, and data contracts are not documentation - they are the substrate that lets engineering teams and AI assisted development workflows make consistent decisions at scale. The artefacts produced in this role are clear, reasoned, and durable.
Govern Without BlockingGovernance is a mechanism for alignment and acceleration, not gatekeeping. Structure and discipline are introduced where they reduce risk or improve quality - and removed where ceremony adds cost without value. The role engages the Chief Architect early, pushes back constructively when platform standards do not fit the ECS context, and helps teams close decisions with conviction rather than endless review.
Reason About Cost and Unit EconomicsInfrastructure choices are sized, cost trajectories modelled for new architecture work, and unexpected spend is flagged with a proposed remediation. The frame is cost per outcome - per protected mailbox, per remediated incident - not just monthly AWS spend.
Communicate at Every AltitudeA one page decision record that lands with engineers, a solution brief that holds up under senior architecture review, a strategy narrative that resonates with product and commercial leadership - this role operates across all of those registers. Whiteboard sessions produce actual decisions, not just richer ambiguity.
What You Will BringMimecast is an equal opportunity employer committed to an inclusive and diverse workplace. We consider everyone equally: your race, age, religion, sexual orientation, gender identity, ability, marital status, nationality, or any other protected characteristic won't affect your application.
The base salary range for this position is £124,000 - £186,000 base + benefits. This reflects the minimum and maximum target for new hire salaries for this position. This position may also be eligible for incentive plans and other related benefits. Our salary ranges are determined by role, level, and location. These factors and individual capabilities will also determine the individual pay offered.