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Staff / Principal Backend Software Engineer

Twenty · Arlington, VA · On-site

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About Twenty

The #1 Open Source CRM for modern teams. Modular, scalable, and built to fit your business. Backed by Y Combinator.

About the role

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.

What they're looking for

  • 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
More about this role

America is under sustained cyber attack. Our adversaries infiltrate our networks, steal our IP, and degrade the digital infrastructure that modern life runs on. They’ve learned—correctly—that those attacks rarely produce consequences.

Twenty was founded to change that, by making our adversaries think twice before they attack us. Our vision is American and allied primacy in cyberspace—a future where they cannot contest us, deterrence is assured, and the free world remains secure.

Founded in 2024, Twenty Technologies ( www.twenty.io ) industrializes offensive cyber operations for the U.S. and its allies. Headquartered in Arlington, Virginia, Twenty has raised $168M from Khosla Ventures, Accel, Caffeinated Capital, Friends & Family Capital, Point72 Ventures, General Catalyst, and In-Q-Tel.

Mission | On Site | Full Time | U.S. Citizenship Required / No Active Clearance Required

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,...

Read the full posting on Twenty's site ↗

Engineering

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