Senior Full-Stack AI Product Engineer Cross-Platform

Happy Scribe Ltd.; Bellprat; Hybrid; EUR 90,000 - 120,000; Full time

Benefits offered by this job

Competitive salary

Equity

Generous token spend policy

30 days holiday allowance

Health coverage

Tax-smart savings

Job summary

HappyScribe in Barcelona is looking for an experienced engineer to join the Engagement pod. You’ll own a product area from day one across Rails backend and React web, React Native mobile, and Electron desktop apps.

Work with a designer to decide what to build, prototype it, ship it with coding agents, and validate it with evidence.

You’ll grow the design system, contribute to architecture decisions, and help the team balance speed with rigor in a hybrid, English‑fluent environment.

Qualifications

• 5+ years of software development experience.
• Shipped cross‑platform apps (mobile or desktop).
• Proven AI‑first approach using coding agents.
• Experience building design systems or component libraries.
• Ability to ship with minimal specifications.
• Fluent English in a global team.

Responsibilities

• Own Engagement features end to end across Rails backend and React web, React Native mobile and Electron desktop apps.
• Decide with your designer what to build, prototype it, ship it with coding agents, and prove it works with evidence.
• Grow our design system and component library together with the designer.
• Make architecture calls across the stack and raise the pod’s bar.

Skills

Full-stack in production

AI-first mindset

Cross-platform app experience

Design system / component library

Product judgment

Ambiguity tolerance

English fluency

Shipped mobile or desktop app

Collaborative with designers

Tools

Ruby on Rails

React

Electron

Job description

HappyScribe in Barcelona is looking for an experienced engineer to join the Engagement pod. You’ll own a product area from day one across Rails backend and React web, React Native mobile, and Electron desktop apps.

Work with a designer to decide what to build, prototype it, ship it with coding agents, and validate it with evidence.

You’ll grow the design system, contribute to architecture decisions, and help the team balance speed with rigor in a hybrid, English‑fluent environment.