--- title: 'Senior Full Stack Engineer at Sphinx Defense' canonical: 'https://feeny.ai/job/senior-full-stack-engineer-sphinx-defense-el-segundo-hdp8n8d5ns48' type: 'job' last_seen: '2026-09-08' --- # Senior Full Stack Engineer at Sphinx Defense - **Company:** Sphinx Defense - **Location:** El Segundo, CA - **Posted:** 2026-08-25 - **Last confirmed live:** 2026-09-08 - **Apply:** https://job-boards.greenhouse.io/sphinxdefense/jobs/5405919008 ## Job description ## 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by engineers and technologists with deep experience across commercial and defense technology, we were frustrated by the outdated and insecure technology America's service members are forced to rely on.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. ## ABOUT THE ROLE 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 support the U.S. 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, high-quality user interfaces and front-end experiences for Sphinx’s space vehicle mission planning platform, while also contributing across the full stack. We’re seeking an experienced engineer with strong front-end development expertise and a solid understanding of backend development, APIs, databases, and service integration. You’ll work as an individual contributor while also proiding technical leadership and mentorship to more junior engineers. What you will be focusing on: - Applying a strong understanding of modern front-end development to build intuitive, responsive, and maintainable user experiences using technologies such as JavaScript, TypeScript, React, Angular, and/or Vue - Translating design mockups, user feedback, and system requirements into functional, visually appealing, and intuitive user interfaces - Building performant, secure, and well-tested web applications with a focus on scalability, automation, usability, and security - Leading the development of critical features across the full software development lifecycle, with significant influence from user feedback, system requirements, design engineering, and evolving customer needs - Designing, developing, and improving APIs and backend services that effectively support front-end applications and system capabilities - Developing and maintaining backend functionality using technologies such as Python, SQL, RESTful APIs, and containerized architectures - Collaborating closely with QA and other engineering disciplines to define acceptance criteria, meet functional and technical requirements, identify defects, and ensure software quality - Writing and maintaining automated unit, integration, and functional tests to validate functionality and ensure requirements are met - Conducting thorough code reviews to maintain code quality, enforce best practices, and ensure adherence to established standards - Advocating for improvements to product usability, quality, security, and performance that positively impact your team and end users - Supporting junior engineering talent through mentorship and technical guidance You might be a good fit if you have: - 5+ years of progressively responsible web or software development experience using modern development approaches - Strong front-end development experience, with a deep understanding of modern UI development principles, component-based architecture, responsive design, performance, and usability - Extensive experience with JavaScript, TypeScript, HTML, CSS, and modern front-end frameworks such as React, Angular, and/or Vue - Experience translating designs, user needs, and requirements into intuitive, production-quality user experiences - Strong full-stack fundamentals with the ability to work effectively with backend systems, including Python, API development and integration, application architecture, and service-to-service communication - Experience working with relational databases and SQL, including querying and integrating data into web applications - Experience designing, consuming, and integrating APIs between front-end applications and backend services - Understanding of modern containerized and microservices architectures using technologies such as Docker and Kubernetes - Experience collaborating with QA throughout the software development lifecycle, including defining acceptance criteria, troubleshooting defects, validating functionality, and supporting release readiness - Demonstrated experience writing automated tests and developing software against defined user, functional, and technical requirements - A strong understanding of software engineering best practices, including code reviews, version control, automated testing, security, performance, and maintainability - Comfort working with ambiguity, self-directing your work, and providing technical guidance to other engineers - A demonstrated ability to own technical problems end-to-end and make sound engineering tradeoffs - Excellent communication skills and experience working with end users and cross-functional teams to design and build solutions that meet their needs - Experience developing, testing, and deploying software within air-gapped or highly secure government network environments - Have the ability to hold and maintain a U.S. Government TS/SCI clearance Bonus points if you have the following: - Experience designing and developing intuitive user interfaces featuring real-time, 2D/3D geospatial visualizations - Experience building software for mission-critical, defense, aerospace, or other highly secure environments - Actively hold a U.S. Government Secret Clearance ## LOCATION This role is a hybrid role and can be based out of Colorado Springs, CO, El Segundo, CA, or Chantilly, VA. ## COMPENSATION This role is between $157,000 - $190,000 base salary. ## BENEFITS Compensation includes competitive salary, meaningful equity ownership, profit sharing, employer 401(k) contribution, and 100% employer covered medical, dental, and vision insurance for you and your dependents. ## ELIGIBILITY Must be a US Citizen and be able to obtain and hold a U.S. Top Secret security clearance and be eligible to obtain and maintain a TS/SCI clearance . ## EEO STATEMENT At Sphinx Defense, we are devoted to building a team that represents a variety of backgrounds, perspectives, and skills. Sphinx Defense is committed to providing equal employment opportunities to all employees and applicants for employment without regard to race, color, religion, sex, sexual orientation, and gender identity. CLEARANCE ELIGIBILITY - This position requires eligibility to obtain and maintain a U.S. security clearance. For more information about U.S. Security Clearances: [click here](https://www.state.gov/security-clearances#:~:text=Security%20clearances%20only%20apply%20to,behalf%20of%20the%20federal%20government.). To conform to U.S. Government export regulations, applicant must be a (i) U.S. citizen or national, (ii) U.S. lawful, permanent resident (aka green card holder), (iii) Refugee under 8 U.S.C. § 1157, or (iv) Asylee under 8 U.S.C. § 1158, or be eligible to obtain the required authorizations from the U.S. Department of State. Learn more about the ITAR [here](https://www.pmddtc.state.gov/?id=ddtc_kb_article_page&sys_id=24d528fddbfc930044f9ff621f961987). ## About Sphinx Defense ## Core Business - **Primary Industry**: Defense / Space – Satellite ground systems software - **Target Customers**: U.S. Government (including military) and commercial satellite operators – B2B/Enterprise - **Mission**: Solve the toughest ground-side challenges in satellite operations, making data transfer faster, smarter, and more secure. [sphinxdefense.com/what-we-do/](https://sphinxdefense.com/what-we-do/) ## Products & Services - **SCOPe (Sphinx Contact Optimization & Planning Engine)**: A proprietary platform that eliminates bottlenecks in satellite operations by identifying optimal time windows for downlinking and uplinking data between satellites and ground stations. Available for licensing. [sphinxdefense.com/what-we-do/](https://sphinxdefense.com/what-we-do/) - **Ground Transport Communications**: Secure, resilient terrestrial data movement solutions that connect operators to satellites. - **Mission Communications Planning**: Software for link scheduling, bandwidth optimization, and secure data pathways across military and commercial satellite networks. - **Custom Software Development**: Tailored solutions for command and control, SATCOM planning, and cybersecurity challenges. [sphinxdefense.com/what-we-do/](https://sphinxdefense.com/what-we-do/) ## Market Standing - **Valuation / Market Cap**: Not disclosed - **Key Metric**: No public revenue or funding data available - **Notable Investors / Partners**: Not publicly listed - **Growth Signals**: The company is actively hiring (multiple engineering and product roles posted), indicating expansion. [job-boards.greenhouse.io/sphinxdefense](http://job-boards.greenhouse.io/sphinxdefense) ## Competitive Advantages - **Software-Focused, Engineering-Led**: The team is composed entirely of exceptional engineers (front-end, back-end, infrastructure) who concentrate solely on software – no hardware distractions. [sphinxdefense.com/what-we-do/](https://sphinxdefense.com/what-we-do/) - **Speed as Strategy**: Every line of code is delivered mission-ready, with a culture that prioritizes rapid, high-quality output. - **Uncompromising Code Quality**: High standards and a low-ego environment ensure robust, secure solutions. - **Deep Domain Expertise**: Focused exclusively on ground-side satellite problems, a niche that many competitors overlook. [sphinxdefense.com/who-we-are/](https://sphinxdefense.com/who-we-are/) ## Strategic Focus - Continue building and licensing proprietary platforms (like SCOPe) for satellite ground operations. - Deepen partnerships with U.S. Government and commercial space clients. - Expand engineering talent and maintain a distributed, flexible workforce to attract top problem-solvers. [sphinxdefense.com/who-we-are/](https://sphinxdefense.com/who-we-are/) ## Why Work Here - **Mission-Driven Work**: Directly contribute to national security and critical space communications. [sphinxdefense.com/careers/](https://sphinxdefense.com/careers/) - **Engineering Culture**: High standards, low ego, collaboration, and hands-on leadership. - **Remote/Hybrid**: Distributed across the United States with flexible schedules and autonomy. - **Benefits**: Equity ownership, profit sharing, comprehensive insurance, 401(k) contributions, generous vacation policy. - **Inclusivity**: All voices are valued – engineers and non-engineers alike. - **Note**: Some roles require U.S. citizenship and residency within the U.S. due to government contracts. [sphinxdefense.com/careers/](https://sphinxdefense.com/careers/) ## Sources 1. [sphinxdefense.com](https://sphinxdefense.com/) – Company homepage, engineering culture overview 2. [sphinxdefense.com/careers/](https://sphinxdefense.com/careers/) – Careers page with benefits and culture details 3. [sphinxdefense.com/what-we-do/](https://sphinxdefense.com/what-we-do/) – Products, services, and competitive advantages 4. [sphinxdefense.com/who-we-are/](https://sphinxdefense.com/who-we-are/) – Leadership, founders, and distributed team 5. [job-boards.greenhouse.io/sphinxdefense](http://job-boards.greenhouse.io/sphinxdefense) – Open job listings (Senior DevOps, Technical Writer, Product Manager) ## Other roles at Sphinx Defense - [Full Stack Engineer](https://feeny.ai/job/full-stack-engineer-sphinx-defense-remote-7sk9q88jwshe) - [Senior Full Stack Engineer](https://feeny.ai/job/senior-full-stack-engineer-sphinx-defense-chantilly-sk3j0tmxsp4g) — Chantilly, VA - [Senior Full Stack Engineer](https://feeny.ai/job/senior-full-stack-engineer-sphinx-defense-colorado-springs-6aqwy1g9zxdm) — Colorado Springs, CO - [Senior Full Stack Engineer](https://feeny.ai/job/senior-full-stack-engineer-sphinx-defense-remote-16sgpsmpvywq) - [Product Manager (Mission Planning Operations/Ground Terminal Management)](https://feeny.ai/job/product-manager-mission-planning-operations-ground-terminal-management-sphinx-x209g15xbfqe) — El Segundo, CA - [Product Manager (Mission Planning Operations/Ground Terminal Management)](https://feeny.ai/job/product-manager-mission-planning-operations-ground-terminal-management-sphinx-xcy7xtbys5zm) — Colorado Springs, CO - [Product Manager (Mission Planning Operations/Ground Terminal Management)](https://feeny.ai/job/product-manager-mission-planning-operations-ground-terminal-management-sphinx-cmb5e7n6c9b6) — Chantilly, VA - [Junior DevOps Engineer](https://feeny.ai/job/junior-devops-engineer-sphinx-defense-colorado-springs-wv7ejpj5g23t) — Colorado Springs, CO - [Senior Network Engineer](https://feeny.ai/job/senior-network-engineer-sphinx-defense-colorado-springs-qcmzj5f0z7sk) — Colorado Springs, CO - [DevOps Engineer](https://feeny.ai/job/devops-engineer-sphinx-defense-colorado-springs-p77ehbntqwpd) — Colorado Springs, CO