Senior Software Engineer (NSG) Full Time NEW

Role Summary

Sophos Firewall is the flagship product of Sophos, operating in the network security domain to protect customer network traffic when deployed in router or switch mode.As part of the NSG Engineering Group, you will join the Firewall Assistant team in a senior capacity. This team focuses on leveraging AI to interpret natural language queries, deliver intelligent recommendations, and automate firewall operations while upholding enterprise-grade security and compliance standards.The team’s vision is to evolve firewall management from a complex, error-prone manual process into an intuitive, conversational experience—enabling security teams to operate with greater speed, accuracy, and confidence.

What you will do

• Own and deliver the production AI harness (assistant-style features: agent loop, tools, guardrails, and evaluations) while driving developer automation and large-scale migration work.
• Take ownership of end-to-end systems and not prompt-only or notebook-only work.

What you will bring

• Proven experience designing and owning end-to-end distributed systems, including APIs, data models, storage strategies, caching, queuing, and handling failure scenarios and scalability challenges.
• Strong foundation in computer science fundamentals such as data structures, concurrency, networking, and databases, with the ability to reason clearly about latency, throughput, and consistency trade-offs.
• Ability to write clean, testable, and maintainable code, with a focus on robust API design, backward compatibility, and operational excellence.
• Hands-on experience with at least two of the following languages: Python, Go, or Java, including the ability to read and modify code beyond your primary language when needed.
• Experience building and deploying production-grade agents using frameworks such as LangGraph, Claude Agent SDK, OpenAI Agents, or Pydantic-AI, including tool integrations, MCP servers (, FastMCP), and multi-agent orchestration. Familiarity with Temporal, Pydantic, FastAPI, and related ecosystems is highly valued.
• Demonstrated experience developing evaluation frameworks, tracing mechanisms, and regression safeguards for LLM-based systems.

Good to have skills:

• Experience building evaluation frameworks, tracing systems, and regression safeguards for LLM-based applications, beyond reliance on vendor-provided tools.
• Familiarity with prompt caching, KV-cache optimization, model routing, and context engineering to improve cost efficiency and system reliability.
• Experience fine-tuning models (, LoRA, QLoRA, SFT, DPO) for real-world use cases, with measurable improvements in quality—considered a strong differentiator.

#LI-Remote #B2 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