Principal Software Engineer (Backend)

Twenty is seeking a Principal Backend Engineer to work in our Arlington, VA office to architect and lead the development of revolutionary cyber technologies that protect democracies worldwide. We're looking for someone with 12+ years of experience in developing large-scale distributed systems, with mastery-level expertise in Golang, graph databases, and cloud-native technologies, plus a proven track record of driving technical strategy and leading major architectural initiatives across organizations. In this role, you'll serve as the principal technical authority for our backend systems, defining the technical vision and architecture for systems that process real-time cyber operation data at machine speed, lead cross-functional technical initiatives, mentor senior engineers, and drive innovation in how we apply AI, graph databases, and distributed systems to national security challenges. 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 the cutting edge of cyber warfare capabilities. If you're passionate about solving the most complex technical challenges while shaping engineering culture and making a direct impact on national security, we want to talk to you.

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 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 Details

Strategic Technical Leadership

Define and drive the technical architecture and strategic vision for Twenty's backend systems across all products and services

Lead organization-wide architectural decisions and technical initiatives that impact multiple teams and systems

Evaluate and champion adoption of emerging technologies and architectural patterns that could transform our cyber operations capabilities

Serve as the principal technical authority and final decision-maker for complex architectural trade-offs

Drive technical strategy alignment with business objectives and operational requirements

Partner with executive leadership to shape long-term technology roadmaps and investment priorities

Architecture & System Design

Architect highly scalable, fault-tolerant distributed systems that process real-time cyber operation data across multiple domains (cyber network, cyber persona, physical world, electromagnetic spectrum)

Design and optimize sophisticated graph database architectures using Neo4j and AWS Neptune to support advanced AI-powered relationship mapping and intelligence analysis

Lead the design of event-driven architectures using NATS and other message queue systems for real-time communication at scale

Establish architectural patterns and frameworks for microservices that serve as standards across the organization

Drive innovation in applying AI / ML systems integration with graph databases for operational intelligence

Design systems that handle WiFi exploitation, IoT protocol analysis, and electromagnetic spectrum operations at scale

Engineering Excellence & Innovation

Establish and evolve engineering standards, best practices, and development processes across backend teams

Lead research initiatives to explore cutting-edge technologies and methodologies that advance our technical capabilities

Drive innovation in performance optimization, achieving breakthrough improvements in system throughput and latency

Champion engineering excellence through advocacy of testing strategies, code quality standards, and operational excellence

Lead incident response for the most critical system issues and drive systemic improvements to prevent recurrence

Publish technical papers, speak at conferences, and represent Twenty's engineering capabilities externally

Leadership & Mentorship

Mentor and develop senior engineers and technical leads, building the next generation of technical leadership

Lead architecture review boards and facilitate cross-team technical decision-making

Influence and guide technical direction across multiple engineering teams

Collaborate with product leadership to translate complex operational requirements into technical solutions

Build strong relationships with government stakeholders and represent Twenty's technical capabilities at the highest levels

Participate in executive-level technical planning and contribute to organizational strategy

Cross-Functional Collaboration

Work closely with cyber operations experts, intelligence analysts, and forward deployed teams to ensure systems meet mission-critical requirements

Partner with SRE teams to ensure operational excellence and reliability of backend systems in secure government environments

Collaborate with frontend teams to design optimal API contracts and data structures

Coordinate with security teams to implement defense-in-depth architectures and threat mitigation strategies

Engage directly with government customers to understand evolving mission needs and validate technical approaches

Qualifications

Technical Skills & Experience

12+ years of professional software development experience with increasing technical leadership responsibilities

Mastery-level proficiency in Go (Golang) with demonstrated ability to design and implement large-scale production systems

Proven track record of leading major architectural initiatives and technical transformations

Deep expertise in distributed systems architecture, consensus algorithms, and fault tolerance patterns

Expert-level experience with graph databases (Neo4j, AWS Neptune, or similar) including advanced query optimization and schema design

Extensive experience architecting event-driven systems, message queues (NATS, Kafka, RabbitMQ), and real-time data processing

Advanced proficiency with cloud platforms, particularly AWS, including deep knowledge of networking, security, and infrastructure services

Expert knowledge of containerization, Kubernetes, microservices architectures, and service mesh technologies

Deep understanding of security architecture, zero-trust principles, secure coding, and threat modeling

Extensive experience with performance engineering, profiling, optimization, and capacity planning for high-throughput systems

Strong background in AI / ML systems integration and production deployment of machine learning models

Experience with Infrastructure as Code (Terraform, CloudFormation) and GitOps practices

Leadership & Strategic Skills

Demonstrated experience as a technical leader driving architecture decisions across organizations

Proven ability to influence without direct authority and build consensus among diverse stakeholders

Strong track record of mentoring senior engineers and building high-performing technical teams

Exceptional communication skills with ability to explain complex technical concepts to executive leadership, government stakeholders, and technical teams

Experience leading technical due diligence, vendor evaluations, and build-vs-buy decisions

Demonstrated ability to balance technical excellence with business pragmatism and delivery timelines

Track record of driving cultural change and establishing engineering best practices organization-wide

Domain Expertise

Experience with large-scale data processing, analytics, and intelligence production systems

Knowledge of cyber threat intelligence, threat actor attribution, and persona analysis

Understanding of electromagnetic spectrum operations, WiFi protocols, and IoT security

Familiarity with government security requirements, compliance frameworks, and operational constraints

Education

Bachelor's degree in Computer Science, Software Engineering, or related field; Master's degree or PhD preferred

Equivalent practical experience in lieu of formal education may be considered for exceptional candidates

Security Requirements

Must be eligible to obtain and maintain a security clearance

Ability to work on-site in Arlington, VA with occasional travel to Fort Meade, MD and other government facilities

Distinguishing Qualifications

Previous experience as Principal Engineer or Staff+ level role in technology companies

Track record of delivering complex technical solutions in defense, intelligence, or national security contexts

Published research, patents, or recognized contributions to the software engineering community

Experience with defense acquisition processes, government program management, or public-private partnerships

Background in training and mentoring across multiple organizations or companies

Previous experience founding or leading engineering teams at startups or high-growth companies

Advanced technical certifications in cloud platforms, security, or distributed systems

Open-source project leadership or significant contributions to major projects

Speaking engagements at major technical conferences or industry events

Experience with multiple programming languages beyond Go (Python, Rust, Java, C++)

Additional Skills

Expert knowledge of database systems (relational, document, time-series, and graph databases)

Experience with observability platforms (Prometheus, Grafana, ELK stack, Datadog, New Relic)

Understanding of compliance requirements (FedRAMP, NIST, DoD security standards) and secure development lifecycle

Experience with advanced networking concepts, SDN, and network function virtualization

Knowledge of hardware acceleration (GPUs, FPGAs) for compute-intensive workloads

Experience with multi-cloud and hybrid cloud architectures

Experience with real-time streaming analytics and complex event processing

Knowledge of data governance, data lineage, and metadata management systems