Senior Software Engineer

Overview

Senior Software Engineer on Mimecast's Managed Threat Response engineering team, leading engineering design for significant system areas across Mailroom and Threat Portal, with contributions to Managed Email Incident Response and Remediation products. The role combines distributed systems engineering, AI-first development, technical leadership, mentorship, and incident response.

What you'll do

• Lead engineering design for significant system areas, from framing the problem through to a system running reliably in production.
• Design distributed components that stay available and scale horizontally, reasoning about race conditions, partial failure, and data consistency.
• Produce design documents, comprehensive test coverage, proactive observability, and clear technical documentation.
• Use agentic AI development tools as a primary working method and build reusable workflows, context and prompt patterns, and evaluations for the team.
• Own the quality of everything you merge and set the standard for reviewing AI-generated code.
• Balance technical trade-offs against product and delivery commitments and make that reasoning visible to Product and Engineering leadership.
• Mentor junior and mid-level engineers through pairing, design review, and code review.
• Align stakeholders behind a technical direction the team can execute with confidence.
• Lead critical incidents spanning multiple services, including diagnosis, communication, and preventive follow-up work.
• Monitor resource usage for cost savings that do not compromise performance or reliability.
• Work with Product, Support, and other engineering teams to drive cross-team collaboration.
• Engage in backlog refinement, planning, design and code reviews, demos, and retrospectives.

What you'll need

• Deep expertise and system-level design judgement.
• Command of your core stack plus fluency in adjacent systems.
• A track record of designing components whose failure modes, cost profile, and cross-service effects on reliability and security were considered up front.
• Around six or more years building production software, including system areas owned through multiple iterations, real incidents, and subsequent architectural changes.
• Demonstrable day-to-day development with agentic coding tools rather than occasional autocomplete.
• Evidence of deliberately raising someone else's AI development practice through workflows, tooling, patterns, or standards that others adopted and kept using.
• A working understanding of where AI development tools fail, including hallucinated APIs, plausible-but-wrong logic, and silent security and performance regressions.
• Discipline never to merge code you cannot explain.
• Credibility to hold a team to the standard of not merging code that cannot be explained.
• Strong proficiency in at least one modern backend language.
• Evidence of picking up other languages quickly.
• Relational data modelling and query performance skills using PostgreSQL or similar.
• Experience with distributed building blocks such as Redis caching and Elasticsearch search engines.
• Containerisation skills.
• CI/CD pipeline skills.
• Foundational AWS services skills.
• Influence, deliberate mentorship, and clear written communication.
• Ability to explain technical concepts credibly to non-technical stakeholders.
• Ability to collaborate well across a team distributed over multiple time zones.

Nice to have

• Front-end experience with JavaScript, TypeScript, Angular, or React.
• Java experience.
• Prior work in cybersecurity or email security.
• Hands-on experience building LLM-backed application features such as retrieval, tool use, or evaluation harnesses.

Details

• Location: Bengaluru, India.
• Hybrid working model.
• Employees are expected to come to the office at least two days per week.
• Collaboration takes place across multiple time zones.
• Applicable background checks are required as a condition of employment.