Senior Backend Software Engineer

Stack

Responsibilities

• ▹Design and implement scalable backend services in Go
• ▹Build high-performance APIs that power customer-facing workflows and internal platform capabilities
• ▹Model complex relationships in graph databases and optimize schemas and queries for speed and clarity
• ▹Implement event-driven systems (e.g., with NATS) to process real-time operational data streams
• ▹Develop and maintain automated tests to protect correctness, security, and performance
• ▹Build and operate microservices deployed on AWS, with an eye toward resilience and cost-aware scaling
• ▹Create and improve CI/CD pipelines that enable fast, secure delivery of new capabilities
• ▹Partner with cyber operations experts to translate domain needs into robust product features
• ▹Collaborate with frontend engineers on API contracts and data structures that are efficient and usable
• ▹Evaluate new technologies and patterns that could unlock better operational outcomes

Requirements

• ▹5+ years of professional software development experience building backend (or full-stack) applications
• ▹Strong proficiency with Go (Golang) and experience shipping production services with it
• ▹Experience working with graph databases (Neo4j, AWS Neptune, or similar), including schema design and query performance
• ▹Working knowledge of event-driven architectures and message queues/streaming systems
• ▹Experience building and maintaining APIs (REST and/or GraphQL)
• ▹Experience with cloud infrastructure, ideally AWS, and cloud-native deployment patterns
• ▹Hands-on experience with containerization and microservices architectures
• ▹Strong foundation in secure coding practices and ability to reason about security tradeoffs
• ▹Bachelor's degree in Computer Science, Software Engineering, or a related field, or equivalent practical experience

Nice to have

• ▹Delivered software in defense, security, or other mission-critical environments
• ▹Built systems for analysts, operators, or high-tempo users where speed and reliability matter
• ▹Integrated AI/ML capabilities into production systems (inference, pipelines, or tooling)
• ▹Experience with large-scale data processing and analytics workloads
• ▹Meaningful open-source contributions
• ▹Used observability tooling (metrics, tracing, logging) to debug and improve production systems

Soft skills

What we offer

• ▹Medical, dental, and vision plan options
• ▹Life / AD&D and disability coverage options
• ▹Paid parental leave (12 weeks for birthing parents, 4 for non-birthing parents, 6 weeks for adoptive, foster, or surrogacy parents)
• ▹Paid holidays and flexible PTO
• ▹401(k) with pre-tax and Roth options
• ▹HSA/FSA options, dependent care FSA

About the company

Founded in 2024 and headquartered in Arlington, Virginia, Twenty Technologies industrializes offensive cyber operations for the U.S. and its allies. The company has raised $138M from investors including Accel, Caffeinated Capital, Point72 Ventures, General Catalyst, and In-Q-Tel. Due to U.S. government contract and security requirements, this role is limited to U.S. citizens.