Staff / Principal Backend Software Engineer

About the Company At Twenty, we're taking on one of the most critical challenges of our time: defending democracies in the digital age. We develop revolutionary technologies that operate at the intersection of the cyber and electromagnetic domains, where the speed of operations exceeds human sensing and complexity transcends conventional boundaries. Our team doesn't just solve problems – we deliver game-changing outcomes that directly impact national security. We're pragmatic optimists who understand that while our mission of protecting America and its allies is challenging, success is possible. Role Summary You’ll design and build backend systems that turn real-time operational data into mission-critical capabilities. This role owns core services that need to be fast, reliable, and secure—operating across cloud and on-prem environments. You’ll make high-leverage architecture decisions, drive technical execution, and raise the bar through mentorship and engineering standards. You’ll partner closely with product, operations, and frontend teams to ship systems that work under real-world constraints.

Who You Are You’re motivated by high-stakes, real-world outcomes—especially in national security and cyber operations. You take ownership: you push projects from ambiguous problem to shipped, measured capability. You bring calm, high-judgment leadership during incidents, tradeoff discussions, and tight timelines. You hold a high bar for reliability, security, and maintainability—and you help others meet it. You communicate clearly with both technical and non-technical partners. You prefer simple, scalable designs and know when complexity is justified. You enjoy mentoring and leveling up engineers through feedback, pairing, and strong technical direction. What You’ll Do Architect and build high-throughput backend services that process real-time operational data. Lead technical design reviews and choose pragmatic approaches for new features and system improvements. Design event-driven and distributed systems that are resilient, observable, and performance-tuned. Define stable APIs for internal and external consumers, partnering with frontend for seamless integration. Improve engineering excellence through code reviews, standards, testing strategy, and incident practices. Build and maintain CI/CD workflows that enable rapid, secure delivery. Troubleshoot complex production issues, lead incident response, and drive durable fixes. Partner with product and operational stakeholders to translate needs into deliverable technical plans. Contribute to technical strategy and roadmap planning across backend services. Support hiring by participating in interviews and helping define what “great” looks like. Must Have You have 10+ years building scalable backend systems in production environments. 4+ years of experience in Golang, or 4+ years writing server-side business logic in an object-oriented language (Java, Kotlin, C#, Python) or systems language (C, C++, Rust) with strong system design aptitude. You have led technical initiatives end-to-end, including architecture, execution, and delivery. You have experience designing distributed systems (e.g., event-driven architectures, messaging, consistency tradeoffs). You have built cloud-native services and operated them in production (AWS preferred). You have strong security fundamentals: secure coding, threat modeling, and defensible design choices. You have a track record mentoring engineers through code reviews, technical guidance, and feedback. You have strong communication skills and can align teams around clear technical decisions.