Senior Architect (Email & Collaboration Security)

Join Mimecast, a leading email and collaboration security company, as a Senior Architect. In this role, you will be responsible for shaping the technical direction of the Email & Collaboration Security (ECS) product line, which addresses critical challenges in enterprise security. You will work closely with product management, engineering, and the Architecture Leadership Team to turn customer and business problems into coherent technical solutions. The ideal candidate will have over 10 years of experience in building and operating production SaaS systems, a strong understanding of cloud-native patterns, and a genuine customer orientation.

• Lead the architectural direction for the Email & Collaboration Security (ECS) product line, ensuring alignment with business goals and customer needs.
• Facilitate workshops and discussions with product management, UX, and engineering teams to identify customer constraints and articulate desired outcomes.
• Own integration contracts and product artefacts, ensuring durable interfaces and coordination across teams for successful implementation.
• 10+ years building and operating production SaaS systems, with at least 3 years in a Solutions Architect, Principal Engineer, or equivalent role carrying product-shaping responsibility
• Comfort operating across cloud-native patterns (AWS, Kafka, managed services, distributed event architectures) at high throughput — able to reason about trade-offs with confidence, without needing to be the most technically specialist person in the room
• A genuinely broad architectural lens — thinking about system shape, data flows, and organisational constraints rather than reaching for the nearest deep technical rabbit hole
• Genuine customer orientation: asking what problem the customer has before asking how to build the feature
• Understanding of SaaS unit economics, the commercial implications of architectural choices, and how to reason about scale from a product perspective as well as a systems one
• Prior close collaboration with Product Managers and UX designers, with an understanding of jobs-to-be-done framing and a real opinion on what makes a product bet good — not just a technical bet
• An understanding of what twenty years of software history means in a production system — no assumption of greenfield, and no treatment of legacy as only debt; it is accumulated context
• An ability to connect dots across a large picture with many moving parts, make a call, and communicate it clearly — rather than waiting for certainty that will not arrive
• Structure and discipline as cognitive defaults, not imposed processes — thorough, well-reasoned artefacts, and a habit of leaving things clearer than they were found
• Thrives with ambiguity and treats it as a problem to be structured, not a reason to pause
• A proactive self-starter who identifies the right problems to work on without being told, and drives them to resolution
• Comfortable acting independently within a set of principles, while keeping the right stakeholders informed and in sync — not seeking permission, but maintaining alignment
• Able to reach a solution even without all the knowledge in front of them — a problem-solver who knows how to navigate to an answer, not a mnemonic database
• Stays ahead of where the market and the technology are going, and brings that signal back into product and architecture decisions
• AI tooling treated as a core capability multiplier, with a real daily practice in design work, documentation, research synthesis, and prototyping
• Background in email security, threat detection, DLP, identity, or data platforms
• Familiarity with agentic AI, MCP (Model Context Protocol), or LLM application architecture
• Exposure to M365 or GWS integration patterns, SMTP relay architecture, or cloud-native security SaaS
• Experience with eval design for AI features, product discovery practices, or data contract / data mesh approaches