Senior Frontend Software Engineer

Sinch SimpleTexting is the leading web-based platform for SMS marketing and business texting in North America. Our software gives organizations the ability to send marketing campaigns, share important alerts, and provide 1-on-1 customer service using text messages. Thousands of organizations rely on Sinch SimpleTexting to connect with their audiences. Our clients include Fortune 500 companies, small businesses, nonprofits, healthcare providers, churches, schools, and more. And with a powerful suite of features that includes segments, autoresponders, data collection and analytics, our platform is designed to help businesses start and scale their engagement through SMS. 

Sinch SimpleTexting is looking for an experienced self-organized Senior Frontend Software Engineer who will actively participate in the key features development and platform’s technical evolution. 
 

You will become a part of an agile product & client-oriented team containing all roles required for autonomous decision making, planning and delivery. We have mature engineering processes including daily production releases evolved over the years yet startup like friendly and open for new ideas work environment. Our teams follow a hybrid working model, and this role will be based out of the Madrid Sinch office. 

*Please apply your resume in English!

What do you do in the role? 

• Develop and maintain scalable, high-performance frontend applications using ReactJS and TypeScript 

• Build intuitive and developer-friendly interfaces for designing, deploying 

• Work closely with product designers to translate UX/UI wireframes into beautiful and functional user experiences 

• Optimize performance, accessibility, and responsiveness of the application 

• Implement state management solutions and scalable component architectures 

• Integrate frontend applications with RESTful APIs and GraphQL endpoints 

• Ensure a high-quality codebase with a strong focus on testing (unit, integration, and end-to-end tests) 

• Stay up to date with the latest advancements in React, TypeScript, and frontend development best practices 

• Work in a collaborative, fast-paced environment, contributing to architecture and design decisions 

What experience/qualities you need to bring with you 

• Proven experience developing frontend applications using React and TypeScript 

• Strong understanding of modern UI frameworks, component-driven design, and best practices 

• Experience with state management libraries like Redux or React Query 

• Knowledge of performance optimization techniques, including lazy loading, memorization, and code splitting 

• Experience working with RESTful APIs, WebSockets, and GraphQL. 

• Familiarity with design systems, reusable UI components, and accessibility standards (a11y) 

• Understanding of frontend build tools (Webpack, Vite, Babel) and modern development workflows (CI/CD) 

• Experience writing unit, integration, and end-to-end tests using Jest, Playright 

• Strong problem-solving skills and ability to work in a collaborative, cross-functional team 

• Love of learning and sharing knowledge 

Nice to have

• Experience with messaging products and platforms 

• Familiarity with microfrontend architecture 

• Understanding of real-time applications and event-driven UI patterns 

• Exposure to design tools like Figma and working closely with designers