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Salary: USD 200,000 - 260,000 / annual
Legion is an AI infrastructure company born from a Department of Defense partnership, trusted by government and enterprise leaders. The company builds secure, reliable systems that embed intelligence inside complex, mission-critical platforms—optimizing workflows rather than replacing them. Legion collaborates with world-class partners including Palantir, Nvidia, HPE, and Oracle to deliver intelligent infrastructure at the edge and across enterprises.
As Principal Software Engineer for Platform, you will design and develop foundational components and frameworks that serve as the building blocks for Legion's Agentic AI platform. You'll play a primary role in developing and maintaining core infrastructure, with your Rust expertise enabling significant contributions to the technology stack.
Key responsibilities include:
- Design and develop foundational components and frameworks for the AI platform
- Collaborate with cross-functional teams to understand needs and create platform solutions that empower developers
- Stay current with design patterns, techniques, and technologies that attract developers to platforms
- Work closely with machine learning engineers to build infrastructure supporting ML workflows in enterprise environments
- Provide production support and troubleshooting expertise, ensuring smooth operation and addressing performance/scalability challenges
You will work on performance-critical systems developed in Rust, designing high-performance distributed systems that support AI and machine learning workloads. The role requires deep expertise in database architecture, scalable data systems, workflow engines, and AI orchestration frameworks.
REQUIREMENTS:
- US Citizenship or Greencard (Permanent US Residency) required due to US Government contract requirements
- Must be domiciled in the U.S. (permanent residence with home address in US)
- Must provide legally authorized identification verification through CLEAR ID as part of application process
- Bachelor's degree in Computer Science, Software Engineering, or related field (or equivalent experience)
- 15+ years of software and platform engineering experience with strong track record designing and operating large-scale distributed systems
- Experience building platform infrastructure and backend systems serving multiple products and engineering teams
- Expert-level Rust programming language experience; all performance-critical areas developed in Rust
- Demonstrated expertise in database architecture and scalable data systems (distributed databases, storage, indexing, data modeling, schema design, high-throughput/low-latency access patterns)
- Experience designing systems supporting AI and machine learning workloads
- Familiarity with workflow engines, execution runtimes, and AI orchestration frameworks
- Growth mindset with low ego; eager to learn new tools, learn from others, and adapt when appropriate
- Drive to foster collaboration, psychological safety, and technical excellence
- Strong advocate for inclusion in technical discussions at all levels
PREFERRED QUALIFICATIONS:
- Start-up experience or comfort in 0→1 product environments
- Kubernetes familiarity
- Understanding of DevOps practices and CI/CD pipelines for platform deployment
