Senior Security Engineer

About the role

Lumos (lumos.com https://www.lumos.com) helps every company run a workforce of humans and AI agents safely.

As agents run more autonomously, companies need to know what they can access and control what they can do. Lumos is the identity platform for the agent era. We manage access for every human, machine and AI agent in one place. That way, companies can put AI to work across their business with confidence.

We serve Fortune 500 and high-growth technology companies, including Colgate-Palmolive, Johnson & Johnson and GitHub. Lumos is backed by Andreessen Horowitz, Scale Venture Partners and Neo, along with leaders from OpenAI, Google, Salesforce and Anthropic.

Why Lumos?

- 🚀 Jump on a rocketship. Since launching out of stealth in April 2022, we've grown from 20 to ~130 Alchemists.

- ⭐ Customers love us — and so does the industry. Named a Strong Performer in the 2026 Gartner Voice of the Customer for IGA — 4.7/5, with 96% of reviewers saying they'd recommend us. Our customers cut time-to-access by 98%, slash IT tickets by 72%, and eliminate excess privilege at scale.

- 🏆 A culture worth joining. Three years running on Forbes' Top 100 Best Startup Employers in America (2024, 2025, 2026) — measured on culture, retention, growth, and job creation. That's our Alchemists, not our marketing. See what we live by here https://blog.lumos.com/p/the-anatomy-of-an-alchemist.

Role Overview:

As a Senior Security Engineer at Lumos, you’ll shape the identity platform thousands of IT and security teams rely on to protect their data. You’ll build the security foundations every Lumos product runs on and be a trusted voice when our largest customers ask how we keep them safe.

✨ Your Responsibilities

- Design and ship core security platform systems in the Lumos codebase, such as request context propagation across services, scoped API tokens, our authorization service, and decoupling authentication from synced identities.

- Lead multi-sprint security projects end to end, coordinating with engineers on other teams to get them delivered.

- Run security architecture reviews and threat models for new products (for example our MCP Governance gateway and on-device policy checks) before they scale, and turn findings into tracked, prioritized work.

- Drive least-privilege access to our own production systems (databases, data pipelines, AWS IAM, secrets).

- Triage, route, and fix vulnerabilities from pentests, cloud assessments, and dependency scanning, and coordinate retests.

- Take part in security oncall and incident response, and help answer security questions from customers and prospects.

🙌 What We're Looking For

- 5+ years of software engineering experience, with at least 3 focused on security (application, product, or platform security).

- A track record of designing, shipping, and operating production security systems, not only reviewing them. Examples: authentication and authorization frameworks, token and session management, secrets management, audit logging.