Staff Software Engineer (Early Product) at Atomus

Jack & Jill; San Francisco (CA); On-site; USD 190,000 - 260,000; Full time

Job summary

Atomus in San Francisco is seeking a Staff Software Engineer (Early Product) to build the core engines of a multi-platform security ecosystem protecting critical national security technology.

You will bridge desktop agents and cloud infrastructure while guiding foundational systems from a blank page toward scalable, mission-driven impact.

Qualifications

• 7+ years of production-grade software experience in SaaS or multi-platform desktop apps.
• Ability to analyze system behavior across Windows, macOS, and Linux.
• Ownership-driven, fast-moving coder comfortable with ambiguity.

Responsibilities

• Architect and build core infrastructure for security sensing and actions across customer environments.
• Develop and harden a multi-platform desktop agent at fleet scale.
• Collaborate with founders to define engineering patterns, shipping culture, and product strategy.

Skills

Cross-platform development

SaaS platform experience

Desktop agent development

Tools

Windows

macOS

Linux

Job description

Job Title Staff Software Engineer (Early Product)

Salary Not Disclosed

Company Description Atomus is a San Francisco-based cybersecurity startup protecting 100 organizations in the defense industrial base, including the US Air Force, Space Force, and Navy, by automating complex security and compliance requirements for national security technology.

Job Description As a Staff Software Engineer at Atomus, you will build the core engines of a multi-platform security ecosystem protecting the nation’s most sensitive defense technologies. You will bridge the gap between desktop agents and cloud infrastructure while shaping the engineering foundations of a high-stakes, mission-driven startup during its most critical growth phase.

Location San Francisco, USA

Why this role is remarkable

• Join a mission-critical team protecting the organizations building hypersonic aircraft, satellites, and autonomous defense platforms essential to national security.
• Work on a product with massive traction, already securing 100 customers including the US Air Force and Navy, while still operating as a small, high-impact founding team.
• Tackle unique engineering challenges across Windows, macOS, and Ubuntu while developing next-generation agentic systems that automate complex security reasoning.

What You Will Do

• Architect and build the core infrastructure that senses, correlates, and acts across diverse customer security environments to ensure total protection.
• Develop and harden a multi-platform desktop agent at fleet scale, ensuring it remains unbreakable across Windows, macOS, and Linux distributions.
• Collaborate directly with founders to define engineering patterns, shipping culture, and product strategy as the team scales from early stage to industry leader.

The ideal candidate

• 7 years of experience building production-grade software, specifically customer-facing SaaS platforms or sophisticated multi-platform desktop applications and agents.
• Expertise in diving deep into system behavior and low-level interactions to understand why software behaves the way it does across different environments.
• A fast-moving, ownership-oriented mindset that thrives on ambiguity and the challenge of building foundational systems from a blank page.