Sklum Digital & AI is an agentic-native team: a small, high-leverage group that heavily uses agentic AI workflows to build applications and scale our impact far beyond traditional team sizes. For this role in particular, agentic fluency is essential - you will be expected to use agentic tooling every day to multiply your own output, and to help shape how the team leverages these tools. We are looking for a Principal Fullstack Engineer to be a major hands-on builder of the new Sklum app, which we are building from scratch. This is a mobile-first fullstack role: the primary focus is React Native for mobile, extended with the backend work needed to deliver features end-to-end.
This is a primarily hands-on individual contributor role - you will spend most of your time writing and shipping production code. You will report to the Principal Engineer - Architect and work closely alongside the Principal Software Engineer - Backend & Data and other senior engineers to deliver the app from zero to one.
What you'll be doing Mobile-First Fullstack Engineering
Design, build,



and ship features end-to-end across the Sklum app - from the React Native mobile experience to the backend services that power it.
Own the mobile experience layer: architecture, navigation, state management, performance, offline behavior, and production-grade patterns in React Native.
Extend into the backend when needed: build APIs, services, and data flows that support the mobile experience, in close collaboration with the Backend & Data engineer.
Contribute to the web experience (React / Next.js) where features span platforms, ensuring consistency of behavior and design system across mobile and web.
Quality, Performance, and Craft
Write production-grade, well-tested, observable code; own features end-to-end from design through deployment and on-call.
Drive performance, reliability, accessibility, and security of the mobile experience.
Establish and maintain engineering standards for the fullstack work you t

📌 Senior Engineer/Engineering Manager (Valencia)
🏢 SKLUM
📍 Valencia