Experteer Overview
In this role you will own production-grade software across a varied portfolio, partnering with a Product Owner to shape robust, scalable products. You’ll operate in an AI-native, agent-driven environment, translating business needs into well-architected solutions. You’ll frequently move between projects, influencing architecture, quality, and releases. This is a hands-on, strategic engineering role with a clear path to growing influence and a prestigious internal certificate upon demonstrated mastery.

Compensaciones / Incentivos
• Own the build, architecture, quality and release of a product
• Take over and own a product end-to-end after documentation and handoff
• Decide what to build next in collaboration with the Product Owner
• Work across a portfolio of platforms, agent-native products and internal tooling
• Review merges via agent-assisted loop and ensure 100% passing tests
• Design with AI agents to balance quality and speed, and judge outputs critically




• Mentor teammates and contribute to evolving engineering processes and standards
• Contribute to defining the standard stack and participate in architectural governance

Responsabilidades
• Ownership of production software experience
• Front-end and back-end working proficiency
• Strong TypeScript or equivalent language proficiency
• Experience with tests (unit, end-to-end) and test strategy
• Familiarity with coding agents and evaluating agent output
• Ability to understand unfamiliar codebases and explain their purpose
• Fluent English; Spanish useful
• Willingness to work in Barcelona and participate in a team-building environment

Requisitos principales
• Mainloop Barcelona certificate
• no on-call policy
• opportunity to work with AI agents and tooling
• growth through cross-project ownership
• international exposure
• clear ownership of product incidents during work hours

📌 Full-Stack Engineer - Mainloop (Barcelona)
🏢 Leyton Et Associes
📍 Barcelona