Founding Engineer, Infra & Agent Systems

Overview

Cua is building the infrastructure that enables general-purpose AI agents to safely and scalably use real computers and applications.

We're a small team backed by Y Combinator and top-tier investors, and our open-source tools are already used by thousands of developers. As a Founding Engineer, you’ll help turn research prototypes into production-ready infrastructure - powering everything from secure agent runtimes to cross-cloud container orchestration.

We’re looking for someone who brings deep technical ability, strong product instincts, and an eagerness to operate across layers - from OS-level virtualization to developer-facing APIs. You’ll work closely with the founding team on infrastructure design, developer tools, and open-source community building.

Your contributions will shape how autonomous agents interact with real computers at scale - across macOS, Windows and Linux - and how developers deploy and trust them in production environments.

Cua is for builders who care about reproducibility, system safety, and the developer experience of working with AI. If that sounds like you, we’d love to talk.

Responsibilities

• Design and scale infrastructure to run real AI agents on isolated macOS and Linux containers
• Build orchestration systems across cloud providers (AWS, GCP, etc.) for deploying ephemeral agent environments
• Create intuitive APIs and CLIs for developers to launch and control agents
• Contribute to the design of secure, reproducible agent runtimes using Docker, KVM, or similar technologies
• Work closely with early customers, open-source contributors, and the founding team to define roadmap and architecture
• Publish engineering updates, blog posts, and technical documentation to grow the ecosystem
• Participate in product discussions, contribute to internal research, and help drive long-term technical vision

Qualifications

Required:

• 2+ years building and maintaining production infrastructure systems
• Proficiency in one or more of: Python, Go, TypeScript, or Rust
• Experience with backend system design, containers, and cloud environments
• Strong interest in developer tools, AI infrastructure, or distributed systems
• Comfortable operating in a fast-moving, ambiguous, startup environment

Preferred:

• Experience with Docker, KVM, or other OS-level virtualization
• Familiarity with multi-cloud deployment and networking (e.g., AWS, GCP, Azure)
• Performance optimization and debugging experience (e.g., PostgreSQL tuning, cluster orchestration)
• Experience working with AI agents, LLM-generated code, or Copilot-style tools
• Prior open-source contributions or community involvement
• Based in or willing to relocate to Madrid (hybrid setup), but remote OK for exceptional candidates

What We Offer

• Early-stage ownership - Join as a founding engineer with equity and high influence
• Real traction - 9k+ GitHub stars and growing community of developers
• Technical scope - From system internals to developer UX to open-source leadership
• Flexible setup - Madrid preferred, but remote is fine for the right person
• Impact - Define how general AI agents run safely and scalably in production

How to Apply

Please include:

• Your GitHub or portfolio (required)
• A short note on the most interesting developer or infrastructure problem you’ve helped solve
• Bonus: try building something with Cua or contribute to our docs - we notice contributors

We encourage people from all backgrounds to apply - regardless of gender, age, gender identity, sexual orientation, ethnicity, or belief. Applicants’ personal data will be handled in accordance with the GDPR (EU Regulation 2016/679) and industry-standard privacy practices.