Senior Software Engineer

Twenty is seeking a Senior Backend Engineer to work in office in our Arlington, VA office to help build the next generation of cyber technologies that protect democracies worldwide. We're looking for someone with 7+ years of experience in developing scalable applications, with deep expertise in Golang, graph databases, and cloud-native technologies, plus proven leadership experience mentoring engineers and leading technical initiatives. In this role, you'll architect and develop high-throughput systems that process real-time operational data, lead technical design decisions, mentor junior engineers, and drive engineering best practices across our backend services. You'll work with complex graph schemas, design robust GraphQL APIs, and serve as a technical leader who can evaluate engineering courses of action for new features while organizing and managing development workflows. You'll join a world-class product and engineering team that delivers mission-critical solutions for U. S. national security, working in both cloud and on-premises environments to build systems that operate at machine speed. If you're passionate about solving complex technical challenges while leading engineering teams and making a direct impact on national security, we want to talk to you. About the CompanyAt 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 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 DetailsTechnical Leadership & ArchitectureLead the design and architecture of scalable backend solutions using Go that enhance cyber operators' decision-making and response capabilitiesEvaluate and recommend engineering courses of action (COAs) for new features and system enhancementsDrive technical decision-making for complex system integrations and performance optimizationsArchitect efficient data models and complex queries using graph databases to support advanced relationship mappingLead the design and optimization of event-driven architectures using NATS for real-time communication between system componentsTeam Leadership & MentorshipMentor and provide technical guidance to junior engineers, conducting thorough code reviews and knowledge transferOrganize development efforts and assign tasks across engineering teams to optimize workflow and deliveryManage project timelines and coordinate cross-functional collaboration with product, design, and operations teamsEstablish and maintain engineering best practices, coding standards, and development processesLead technical discussions and facilitate architectural decision-making sessionsDevelopment & OperationsDevelop high-performance Go services and microservices architectures deployed on AWS. Create and maintain comprehensive automated testing suites to ensure system integrity and performanceDesign and implement CI/CD pipelines that enable rapid, secure deployment of new capabilitiesTroubleshoot complex system issues and lead incident response effortsResearch and evaluate emerging technologies that could enhance our cyber operations capabilitiesCollaboration & StrategyPartner closely with cyber operations experts to understand and implement features that enhance operator efficiencyCollaborate with frontend teams to ensure seamless API integration and optimal user experiencesContribute to long-term technical strategy and roadmap planningParticipate in technical hiring and interview processesQualificationsTechnical Skills & Experience7+ years of professional software development experience with full-stack applicationsExpert-level proficiency in Go (Golang) with demonstrated ability to write clean, efficient, and maintainable codeProven experience leading technical projects and mentoring junior developersDeep understanding of event-driven architectures, message queues, and distributed systemsExtensive experience with graph databases (Neo4j or similar) and complex query optimizationAdvanced proficiency with cloud platforms, preferably Google Cloud PlatformExpert knowledge of containerization, microservices architectures, and orchestration platformsStrong understanding of security best practices, secure coding principles, and threat modelingExperience with performance profiling, optimization, and scalability engineeringLeadership & Management SkillsDemonstrated experience mentoring engineers and leading technical teamsProven ability to organize development workflows and manage project deliveryStrong communication skills with ability to explain complex technical concepts to diverse audiencesExperience conducting thorough code reviews and establishing development standardsTrack record of driving technical decision-making and architectural improvementsEducationBachelor's degree in Computer Science, Software Engineering, or related field, or equivalent practical experienceSecurity RequirementsMust be eligible to obtain and maintain a security clearanceDistinguishing QualificationsTrack record of delivering complex technical solutions in defense or security contextsExperience with AI/ML integration in operational systemsBackground in developing tools for cyber operators or security analystsExperience with large-scale data processing and analysisAdditional SkillsExperience with Agile development methodologiesSystem architecture and design experiencePerformance optimization and scalability experienceOpen-source contributions or personal projects demonstrating relevant skills Apply to this Job