Principal Software Engineer_Fullstack

About Us
Sophos is a cybersecurity leader defending 600,000 organizations globally with an AI-driven platform and expert-led services. Sophos meets organizations wherever they are in their security maturity and grows with them to defeat cyberattacks. Its solutions combine machine learning, automation, and real-time threat intelligence with frontline human expertise from Sophos X-Ops to deliver advanced, 24/7 threat monitoring, detection, and response.
 
Sophos offers industry-leading managed detection and response (MDR) alongside a comprehensive portfolio of cybersecurity technologies — including endpoint, network, email, and cloud security, extended detection and response (XDR), identity threat detection and response (ITDR), and next-gen SIEM. Together with expert advisory services, these capabilities help organizations proactively reduce risk and respond faster, with the visibility and scalability needed to stay ahead of evolving threats.
 
Sophos goes to market with a global partner ecosystem, including Managed Service Providers (MSPs), Managed Security Service Providers (MSSPs), resellers and distributors, marketplace integrations, and cyber risk partners, giving organizations the flexibility to choose trusted relationships when securing their business. Sophos is headquartered in Oxford, U.K. More information is available at www.sophos.com.

What you will do
Lead the architecture, design, and delivery of end-to-end customer-facing features across web UI, backend services, APIs, and integrations. Write production code, build prototypes, review designs and code, and remain directly involved in solving the most complex engineering problems. Evolve shared frontend and backend platform capabilities so product teams can deliver consistent, accessible, and maintainable customer experiences. Define clear service boundaries, APIs, data contracts, integration patterns, and versioning strategies for capabilities used across multiple Sophos products. Design cloud-native, multi-tenant systems for security, scalability, availability, performance, resilience, and cost efficiency. Apply secure-by-design principles to authentication, authorization, role-based access, tenant isolation, privacy, auditability, and customer-data handling. Build a consistent and secure experience for customers to discover and interact with AI assistants and agents across Sophos products. Develop reusable AI platform capabilities for request routing, context management, tool integration, orchestration, access control, and human oversight. Establish practical approaches for AI evaluation, guardrails, regression testing, observability, latency, cost management, and safe failure behavior. Use AI coding agents throughout the software development lifecycle for codebase exploration, design, implementation, refactoring, test generation, debugging, code review, and documentation; rigorously validate agent-generated changes before release. Establish repeatable agentic development practices for task decomposition, context management, human review, automated verification, and the safe use of coding agents across engineering teams. Translate product goals and ambiguous technical problems into architectural direction and incremental delivery plans. Mentor engineers, raise engineering standards, and build alignment across product, UX, security, applied AI, and platform teams.

What you will bring
12+ years of software development experience, currently operating at Principal, Staff, Architect, or equivalent level. Hands-on experience building production AI applications or agentic workflows - not only prototypes. Strong proficiency using AI coding agents across design, implementation, testing, debugging, code review, and documentation. Strong architecture and system-design experience for large-scale, customer-facing SaaS products. Hands-on backend development with Go and/or Java and frontend development with Angular and/or React. Experience designing, deploying, and operating secure microservices and APIs on AWS. Demonstrated technical leadership, including driving design decisions, solving complex production problems, and mentoring engineers. Cybersecurity domain experience is desirable but not mandatory.

Ready to Join Us?
At Sophos, we believe in the power of diverse perspectives to fuel innovation. Research shows that candidates sometimes hesitate to apply if they don't check every box in a job description. We challenge that notion. Your unique experiences and skills might be exactly what we need to enhance our team. Don't let a checklist hold you back – we encourage you to apply.
 
What's Great About Sophos?
·   Sophos operates a remote-first working model, making remote work the primary option for most employees. However, some roles may necessitate a hybrid approach. While we are a remote first organization, applicants must have legal authorization to work in the jurisdiction where the position is posted, without requiring employer sponsorship.
·   Our people – we innovate and create, all of which are accompanied by a great sense of fun and team spirit
·   Employee-led diversity and inclusion networks that build community and provide education and advocacy
·   Annual charity and fundraising initiatives and volunteer days for employees to support local communities
·   Global employee sustainability initiatives to reduce our environmental footprint
·   Global fitness and trivia competitions to keep our bodies and minds sharp
·   Global wellbeing days for employees to relax and recharge 
·   Monthly wellbeing webinars and training to support employee health and wellbeing
 
Our Commitment To You
We’re proud of the diverse and inclusive environment we have at Sophos, and we’re committed to ensuring equality of opportunity.   We believe that diversity, combined with excellence, builds a better Sophos, so we encourage applicants who can contribute to the diversity of our team.  All applicants will be treated in a fair and equal manner and in accordance with the law regardless of gender, sex, gender reassignment, marital status, race, religion or belief, color, age, military veteran status, disability, pregnancy, maternity or sexual orientation.  We want to give you every opportunity to show us your best self, so if there are any adjustments we could make to the recruitment and selection process to support you, please let us know. 
 
Data Protection
If you choose to explore an opportunity, and subsequently share your CV or other personal details with Sophos, these details will be held by Sophos for 12 months in accordance with our Privacy Policy and used by our recruitment team to contact you regarding this or other relevant opportunities at Sophos.  If you would like Sophos to delete or update your details at any time, please follow the steps set out in the Privacy Policy describing your individual rights.  For more information on Sophos’ data protection practices, please consult our Privacy Policy Cybersecurity as a Service Delivered | Sophos