Backend Software Engineer
AI Summary
Backend Software Engineer at Theori builds and scales AI-driven cybersecurity platforms, architecting backend services and APIs for the Xint autonomous penetration testing framework in a fast-growing, AI-first company.
About this role
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
Skills
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Market data for backend engineer roles
All reports →- Role reportBackend engineer jobs, Sep 2026: new listings up 22.7% in a weekBackend engineer new listings rose 22.7% this week to 481, with 4,949 active roles. Senior positions make up over half. Apply early to new openings.
- SeriesSalary reportsWhat employers publish in job postings, by level and workplace. Not self-reported pay.
- Market overviewState of tech hiring, September 2026: up 4.8%Tech hiring rose 4.8% month over month in September 2026, with 411,122 new listings. Customer support and account executive roles led the growth.
