Senior Frontend Developer (Cells / LitElement)

October 19, 2026

Office

Senior

Madrid, Spain

Keep in mind

Original vacancy is in Spanish
You will likely need Spanish for the job. The employer can confirm
Office-only work

Also worth knowing

English is required
B2 level

Description

A senior frontend role within the architecture area, focused on developing and designing APIs and web applications. The position involves building applications with the latest versions of major frameworks and libraries, applying design patterns, supporting prototype modules and collaborating on Agile projects. Candidates need a frontend background, unit testing skills and fluent English at B2 level.

Responsibilities

Develop web applications with new technologies and the latest versions of major frameworks and libraries from detailed oral and written requirements
Understand and apply common design patterns
Support younger colleagues when they need help or guidance in a specific area
Support the development of prototype versions of software modules and applications
Report progress on assigned tasks and meet defined deadlines
Identify and communicate improvement opportunities
Participate in defining and developing new Front architectures for our clients
Collaborate on projects based on Agile methodologies
Run tests to ensure code quality

Requirements

Experience with frontend development technologies, especially ECMAScript 6
Experience with or interest in Web Components based frameworks such as Lit-Element or Polymer
Unit testing with Jasmine, Mocha, Karma
Openness to working with agile methodologies
Fluent spoken and written English (B2)
Ability to work independently with little supervision
Good communication and presentation skills for local and remote teams
Strong problem-solving and decision-making skills

Conditions

Full-time employment
Inclusive work environment based on cooperation and mutual respect
Equal opportunities plan regardless of race, origin, sex, age, beliefs or identity