Quartermaster is a maritime sensing startup that builds SmartMast, a mast-mounted package of weather-hardened sensors and an analytics platform for continuous distributed maritime monitoring.
ABOUT US Quartermaster is building the world's most comprehensive maritime intelligence platform. Our SmartMast™ system transforms commercial and civilian vessels into a persistent, distributed sensing network—combining HD video, AI, radar, RF sensing, and AIS to deliver real-time maritime domain awareness at global scale. With 600+ sensors deployed across 25+ countries and more than 400,000 vessels identified outside of AIS, we are setting a new standard for what ocean surveillance and safety can look like. We are a mission-driven, high-velocity team building dual-use technology for defense agencies, coast guards, and commercial maritime operators. JOB DESCRIPTION We are looking for a Senior Full Stack Software Engineer to help us build and scale the Quartermaster product—the operator-facing application used by defense analysts, coast guard operators, and commercial fleet managers to monitor, query, and act on maritime intelligence in real time. You will own features end-to-end, from backend geospatial fusion to React components, and your work will directly shape how our customers interact with data collected from sensors spanning the globe. You should be able to work asynchronously across a distributed team. KEY RESPONSIBILITIES - Design, build, and ship full-stack features across our React web portal and Spring backend services. - Develop and maintain versioned RESTful APIs that surface sensor data, vessel telemetry, and AI detection outputs to end users. - Architect and evolve our microservices layer running on AWS, ensuring reliability, scalability, and low latency under high-throughput data conditions. - Optimize PostGIS queries and data access patterns to support bulk artifact retrieval, map rendering, and time-series analysis across hundreds of vessels. - Build internal admin and fleet management tools that help our operations team configure, monitor, and support deployed SmartMast units. - Collaborate closely with our design team to implement pixel-precise UI components for data-dense map views and sensor visualizations. - Participate in on-call rotations and take ownership of service reliability and incident response for your services. - Review code, mentor engineers, and raise the technical bar for the team. QUALIFICATIONS (PREFERRED) - 5+ years of professional full-stack software engineering experience. - Strong command of React and modern JavaScript/TypeScript for building complex, stateful web applications. - Solid backend chops in Spring Boot; experience designing and building REST APIs at scale. - Hands-on experience with PostGIS document databases; able to design schemas and write performant queries. - Working knowledge of AWS services (S3, Lambda, ECS/EKS, IoT Core, CloudWatch) and infrastructure-as-code tooling. - Experience with microservices architecture, containerization (Kubernetes), and CI/CD pipelines. - Ability to read and reason about complex data flows involving real-time streams, large media assets, and geospatial coordinates. - Strong written and verbal communication skills. - Bonus Points: - Experience with geospatial data, mapping libraries (Mapbox, Leaflet, Deck.gl http://Deck.gl), or AIS/vessel tracking systems. - Familiarity with WebSockets or SSE for real-time UI updates. - Background in defense, maritime, or government software with exposure to data security requirements. - Experience integrating ML model outputs into user-facing product features. WORK ENVIRONMENT - Distributed team environment working asynchronously. - Start-up atmosphere with autonomy given to engineers - In office and flexible hours