Principal Software Engineer - XTM One

The role

You will define and drive the technical direction of XTM One, Filigran's AI platform for threat informed defense. You own its architecture, technical standards and vision, and you carry them into the XTM Foundation that sets engineering principles for all products.

What you will do

• Define and carry the technical vision of XTM One over the long term
• Own the platform architecture: agent runtime, tool and MCP integrations, data layers, APIs, permissions, shared commons
• Design for both SaaS and on-premises from day one
• Arbitrate key decisions on scalability, resilience, security, maintainability and cost, including LLM latency and inference cost
• Define team technical principles and get them applied through docs, reviews, pairing and example
• Set the bar for observability and reliability of nondeterministic AI workloads
• Define how OpenCTI, OpenAEV, OpenGRC and future products integrate with XTM One
• Be a full member of the XTM Foundation with other Principal and Staff Engineers
• Write production code, prototype new approaches, and review critical pull requests

Required qualifications

• 10+ years in software engineering, with technical leadership on complex production platforms
• Strong fullstack background with a backend and architecture focus
• Master TypeScript and Python
• Strong system design: distributed systems, scalability, performance, security, observability
• A 360° view of software engineering, from product need to production operations
• Built and operated platforms delivered both as SaaS and on premises
• LLM systems in production: agent frameworks, tool calling, MCP, RAG and vector search, evaluation
• Excellent written communication in English
• Autonomous and at ease in a remote, asynchronous culture

Nice to have

• Cybersecurity domain knowledge: CTI, CTEM, MITRE ATT&CK, STIX/TAXII
• Extensible plugin or tool ecosystems
• Open source contributions or maintainership

Benefits

• Competitive compensation and equity
• Remote-first flexibility
• 25 days PTO baseline
• Paid volunteer days
• Choice of equipment, with additional support for remote work and development needs
• Two annual in-person get-togethers: one company-wide and one team

Before you apply

• The posting states no visa sponsorship information

About the company

Filigran is a global cybersecurity company founded in 2022, building open-source, AI-powered solutions for Continuous Threat Exposure Management. It is fast-growing, remote-first, and operates across Europe, North America and APJ.