Software Engineer

Position: Software Engineer Location: Boston or NYC (On-Site) About Belisar Belisar is the CRM designed for government contracting. It enables the best technology to win, fusing internal context, intuitive AI, and real-time data into a unified view of the market. Federal contracting has long run on tools that were never built for it: Generic CRMs designed for commercial sales, legacy data platforms that surface noise instead of signal, and institutional knowledge locked in spreadsheets and inboxes. Belisar unifies all the important intelligence into a single, AI-native platform — so teams can see opportunities earlier, move faster, and win the work that matters. Belisar is backed by a16z and trusted by leading defense, space, and government leaders including Boeing, Forterra, Scout AI, Vannevar Labs, Aevex, and the Defense Innovation Unit (DIU). Together, we're building toward one outcome: The best technology wins, and it reaches the missions that need it most. The Role We're looking for a full-stack software engineer to join a small, high-density engineering team building Belisar's platform from the ground up. This is a 0-to-1 role in the literal sense: most of what you ship this year doesn't exist yet. You'll own features end-to-end with no handoffs between a “backend team” and a “frontend team” slowing you down. You'll work directly with our CEO, CTO, and founding engineers, sit close to real customers, and make architecture calls that are still running the platform a year from now, not decisions made for you by a platform team five layers up. What You'll Do - Own full-stack feature development end-to-end. - Build in a true 0-to-1 environment: architect greenfield systems rather than patch someone else's legacy stack. - Work across our core stack: React, TypeScript, Python/Django, Postgres, AWS, and applied ML/LLM pipelines - Engage directly with customers in the field and turn what you learn into shipped product within days, not quarters - Make real architecture and infra decisions - Own outcomes, not tickets: you decide what “done” looks like and ship it - Collaborate closely with a small team of sharp engineers and interface directly with the founding team - Help build the technical foundation (CI/CD, data pipelines, ML infra) that the rest of the company builds on top of What We're Looking For - Genuine full-stack range, with comfort owning both the API/backend and the UI within the same project, not just one side - Hacker energy: a demonstrated track record building things (startups, side projects, open source). - Fluent in modern web fundamentals (React, TypeScript) and backend fundamentals (Python, SQL, REST/GraphQL); AWS and ML/LLM exposure a strong plus - High agency: you default to shipping, not waiting for permission or a fully-specced ticket - Comfortable with ambiguity: able to take a vague, real-world problem and turn it into a technical plan - A bias toward speed without sacrificing code quality: you ship polished, production-ready code fast - Excellent communicator, especially translating technical tradeoffs for non-technical stakeholders and customers - US Person required Benefits Belisar offers top-tier benefits for full-time employees, including: - Competitive salary and meaningful equity - Platinum healthcare: comprehensive medical, dental, and vision coverage fully covered for employees and dependents - Basic Life/AD&D and long-term disability insurance fully covered, with the option to purchase additional life insurance for you and your dependents - Relocation assistance available - Unlimited PTO