Backend Software Engineer

We’re looking for an experienced backend engineer to help build and scale the next generation of AI-driven cybersecurity platforms at Theori. You’ll play a key role in architecting and implementing core backend systems that power Xint, our autonomous penetration testing framework.   This is a foundational role in our NA engineering team—ideal for someone who thrives on solving complex systems challenges, enjoys designing for scale and reliability, and wants to help define engineering excellence in a fast-growing, AI-first company.   KEY RESPONSIBILITIES - Architect, develop, and maintain backend services and APIs that power Theori’s AI security platforms. - Design for performance, scalability, and fault-tolerance across distributed systems. - Collaborate with product and frontend engineers to define and deliver secure, well-structured APIs. - Build and optimize data pipelines supporting LLM agent workflows and real-time scanning. - Establish backend best practices, coding standards, and CI/CD processes for a growing US team. - Write clean, well-tested, and maintainable code in Python and related technologies. - Mentor junior engineers and contribute to a strong, collaborative engineering culture.   REQUIREMENTS - 5+ years of professional software engineering experience building production systems. - Strong proficiency in Python, with proven experience developing reliable backend services (FastAPI preferred). - Solid understanding of system design, distributed architectures, and performance optimization. - Experience with Redis, PostgreSQL, and Docker-based environments. - Familiarity with AI/LLM-driven workflows or asynchronous, event-based architectures. - Comfort working in an early-stage environment with evolving requirements. - Self-directed, ownership-oriented, and comfortable driving projects from design to deployment. - Based in US or Canada.   NICE TO HAVE - Experience with Rust. - Background in cybersecurity, application security, or vulnerability analysis. - Knowledge of message queues, task orchestration, or microservices. - Familiarity with LLM integration, RAG pipelines, or vector databases. - Prior experience in startups or B2B SaaS environments. - Previous involvement in building or scaling distributed systems or engineering teams.   WHAT WE OFFER Compensation & Benefits - Competitive salary + equity - Health, dental, and vision insurance - Generous PTO policy - Remote work - Laptop + home office stipend Engineering Culture - Ship features that matter - Modern Python-based stack (FastAPI, Redis, PostgreSQL, Docker) - Strong focus on testing and quality - Clear documentation and processes - Collaborative, low-ego team - Career growth and mentorship Work-Life Balance - Flexible hours, remote-first culture - Focus on outcomes, not hours