Senior Full Stack Engineer

ABOUT SPHINX

Sphinx builds software to solve complex national security problems in Space. Founded by engineers and technologists with deep experience across commercial and defense technology, we were frustrated by the outdated and insecure technology America's service members are forced to rely on. We're here to do better. We’re focused on building modern, scalable products with an emphasis on using open source technologies.

Expect talented, motivated, and interesting colleagues who emphasize collaboration, transparency, and individual responsibility.

Sphinx builds software to solve complex national security problems in Space. Founded by engineers and technologists with deep experience across commercial and defense technology, we were frustrated by the outdated and insecure technology America's service members are forced to rely on. We're here to do better. We’re focused on building modern, scalable products with an emphasis on using open source technologies.

Expect talented, motivated, and interesting colleagues who emphasize collaboration, transparency, and individual responsibility.

Sphinx is hiring a Senior Full Stack Engineer to join our team, building the next generation of mission planning and command and control software for space communications programs. This team is tasked with creating modern, resilient services and capabilities to service the US Government. As our engineering organization continues to scale rapidly, you’ll also play an important role in helping establish strong technical practices, supporting a growing team, and maintaining quality and consistency as we expand.

As a Senior Full Stack Engineer , you will lead the development of intuitive UI/UX and enhance backend services to support Sphinx's space vehicle mission planning platform, which is being leveraged by some of the most important space missions operated by the US Government. We're seeking an experienced engineer with strong front-end development skills AND backend programming fundamentals. You'll work as an individual contributor and a lead for more junior engineers.

• Building performant, secure, tested web applications with a focus on automation and security
• Designing, enhancing, and improving APIs between front-end and backend software services
• Leading the development of critical features across the entire development lifecycle, with significant influence from user feedback, system requirements, design engineering, and evolving customer needs at scale.
• Conducting thorough code reviews to maintain code quality, enforce best practices, and ensure code adheres to established standards
• Creating and translating design mockups into functional, visually appealing user interfaces using modern front-end frameworks (FastAPI, SQL Alchemy, PostgREST, Svelte, React, CesiumJS) and technologies like Python, Java script, Typescript, CSS, and Kubernetes
• Advocating for improvements to product quality, security, and performance that have a particular impact on your team and others
• Supporting junior engineering talent with mentorship or technical guidance

• 5+ years of progressively responsible web development experience with modern software development approaches
• Extensive experience with JavaScript, HTML, CSS, Type Script, web frameworks (React, Svelte), and concepts such as caching, authentication, and CSP
• Deep understanding of open architecture constructs (e.g., OMS, UCI, OCI) and modern containerized microservices architectures (Docker, Kubernetes)
• You are a well-rounded engineer comfortable wearing multiple hats, such as a web designer, UX designer, and engineer
• You possess a strong understanding of backend code with experience integrating the front‑end and the backend (and the willingness to fix the backend when it's needed)
• You are comfortable working with ambiguity and can self‑direct your work while guiding others and supporting project leadership activities
• You understand the importance of, and you have the desire to own a technical problem end‑to‑end
• You've made enough mistakes and booked enough wins to know what not to build and what good looks…