Senior Software Engineer - Frontend

October 23, 2026

Hybrid

Senior

Barcelona, Spain

Keep in mind

Work authorization required

Also worth knowing

Mandatory office attendance
3 days per week

Description

We're looking for a Senior Software Engineer with strong frontend expertise to join an HCM engineering team in Barcelona. The core system runs on Sencha Ext JS 7.5+, while new functional modules and high-performance UI components are being built in React with the Carbon Design System. The role sits at the boundary of the two frameworks and covers end-to-end feature delivery, performance work and architectural decisions in a large-scale modular enterprise product. It is a hybrid position requiring three days a week in the Barcelona office.

Responsibilities

Maintain and enhance the Ext JS foundation while building new capabilities in React
Build new functional modules and high-performance UI components in React
Integrate the Carbon Design System consistently into new development
Ensure seamless interaction between the React components and the existing Ext JS environment
Take ownership of frontend delivery for assigned areas, from Figma designs through to production
Work closely with backend engineers on API integration
Contribute to active sprint work through bug fixes, small features and code reviews
Identify opportunities to improve performance, code quality and the hybrid integration between the two frameworks
Contribute to architectural decisions around the React/Ext JS hybrid approach
Share knowledge with the team on frontend best practices, design system standards and performance optimisation

Requirements

3+ years of professional frontend development experience with strong hands-on commercial experience in Sencha Ext JS as the primary framework
Strong experience with Sencha Ext JS 6.5+ / 7.5+, including Classic toolkit, component inheritance, stores, models, controllers, layouts, theming and the MVVM/MVC lifecycle
Working knowledge of React and its modern ecosystem with the ability to contribute to React-based modules
Strong proficiency in JavaScript (ES6+): object-oriented design, asynchronous programming and advanced debugging
Experience with Carbon Design System or similar enterprise UI frameworks, plus deep knowledge of HTML5, CSS3 and SASS
Experience integrating with RESTful APIs and managing complex state and data in enterprise-scale applications
Confident use of Git, package managers (NPM/Yarn) and build tools (Webpack/Vite)
TypeScript experience for large-scale application development (nice to have)
Familiarity with Ext JS theming, custom SASS/Compass theme development and modernisation of established Ext JS codebases (nice to have)
Background in ERP, HRM or HCM systems with complex user workflows (nice to have)
Knowledge of unit testing frameworks such as Jest, React Testing Library or equivalent frontend testing tools (nice to have)
Valid work authorization for the location, without current or future need for visa sponsorship

Conditions

Hybrid format with three days a week in the Barcelona office
Full-time employment
Fully funded medical and dental insurance
Flexible benefits: exchange part of salary for tax savings on meal and transport vouchers, childcare and training
Free access to the Calm app for up to five users, 24/7 counselling and emotional support from Healthy Mind Coaches
Self-care and parenting resources through the Cleo app
Flexible working: one hour in, one hour out, shortened workdays on Fridays and during the summer
Opportunity to work from over 40 countries for up to 10 weeks per year through the Work Away program
23 working days of annual vacation plus 5 paid volunteering days per year
7 extra days of maternity leave and 5 extra days of paternity leave after one year of service
Life and disability insurance, salary advances of up to 3.5 times net monthly pay and a €300 net marriage bonus
Employee stock purchase plan at a discounted rate
Free premium subscription to external learning platforms