Senior Frontend Engineer — React & UI/UX

Wellfound; Barcelona; On-site; EUR 55,000 - 70,000; Full time

Job summary

Migma in Barcelona, Spain is hiring a frontend engineer to own product experiences from sketch to shipped UI. You will work directly with the two-person founding team, turning designs into polished interfaces using React, Next.js and TypeScript.

You will improve onboarding, campaign editor, and core journeys, crafting accessible, responsive interfaces with strong typography and layout, while keeping code maintainable and aligned with user feedback.

Qualifications

• Proven experience shipping React products in production.
• Excellent HTML and CSS skills with typography and layout sense.
• Strong UX judgment and ability to explain design decisions.
• Comfort turning designs into working interfaces; in-person collaboration in Barcelona.

Responsibilities

• Improve onboarding and core product journeys.
• Design and implement interfaces in React, Next.js, and TypeScript.
• Build reusable components and ensure visual consistency.
• Address responsive layouts, accessibility, and loading/error states.
• Use feedback and analytics to guide improvements.
• Keep frontend code maintainable and performant.

Skills

React

HTML/CSS

UX judgment

Figma

Ownership

Tools

Next.js

Tailwind CSS

TypeScript

Job description

Barcelona, Spain · Full-time · Fully office-based
€55,000–€70,000 gross per year
Candidates must already be based in Barcelona. Visa sponsorship is not available.

Help make powerful AI feel simple.

Migma is building an AI platform that creates and sends on-brand email campaigns end to end. We are a two-person founding team in Barcelona, hiring a frontend engineer who combines strong React engineering with excellent UI and UX judgment.

You will own product experiences from the first sketch to the shipped interface, working directly with the founders. We want someone who can spot a confusing flow, design a better experience, and build it with care.

What you will do

• Improve onboarding, campaign creation, the editor, and other core product journeys.
• Design and implement polished interfaces in React, Next.js, and TypeScript.
• Build reusable components and keep the product visually consistent.
• Handle responsive layouts, keyboard navigation, accessibility, and loading, empty, and error states.
• Use customer feedback and product analytics to decide what to improve.
• Keep frontend code clear, maintainable, and performant.

What we need

• Strong experience shipping React products in production.
• Excellent HTML and CSS skills, with a clear eye for typography, spacing, layout, and interaction.
• Good UX judgment and the ability to explain your design decisions.
• Experience turning designs into working product interfaces; Figma proficiency is useful.
• Ownership, clear communication, and comfort working in a small team.
• Already based in Barcelona and able to work with the founding team in person.

Useful extras

• Next.js, Tailwind CSS, design systems, animation, or complex editor interfaces.
• Experience building AI product interfaces or improving onboarding and activation.
• Thoughtful use of AI coding tools, with responsibility for the final code.