Frontend Developer

Porto, Portugal
Senior (4-6 Years)
Hybrid
English Required

What is this challenge about:

  • Lead the design, development, and delivery of scalable, responsive full stack features for the Business Account portal using React, TypeScript, and GraphQL, with ownership spanning both frontend implementation and integration with backend services.
  • Work closely with product and design teams to understand merchant needs and translate complex financial workflows—such as transfers, scheduled payments, account management, and Strong Customer Authentication (SCA) flows—into secure, end-to-end user experiences backed by reliable APIs.
  • Build and maintain data-rich, high-performance interfaces for transaction feeds, balances, statements, and multi-currency views, ensuring efficient data fetching, state management, and seamless interaction with backend services.
  • Develop and maintain GraphQL schemas, resolvers, and API integrations, ensuring consistency between frontend requirements and backend data models while promoting type safety and end-to-end reliability.
  • Write clean, maintainable, and well-tested code across the stack, applying strong TypeScript practices and contributing to overall system stability, security, and scalability.
  • Actively participate in code reviews across frontend and backend contributions, helping establish engineering best practices in a team transitioning from a mobile-first to a full stack, web-capable organization.
  • Identify and resolve performance bottlenecks, data inefficiencies, and production issues across the full stack, ensuring a smooth, reliable experience for merchant users.
  • Stay up-to-date with the latest frontend technologies, trends, and best practices, applying them to enhance our merchant-facing web platform.

What we are looking for:

  • 5+ years of professional experience in frontend/web development.
  • Expert-level proficiency in TypeScript, including advanced type manipulation, generics, and understanding of complex type inference.
  • Strong proficiency in React.js and its core principles, developed with a type-safe approach.
  • Experience supporting Backend services in Java and Spring Boot
  • Extensive experience with Next.js for server-side rendering, static site generation, and API routes, with a focus on TypeScript integration.
  • Solid understanding of modern JavaScript (ES6+), HTML5, and CSS3.
  • Experience with state management libraries (e.g., Redux, Context API, Zustand) in a TypeScript environment.
  • Strong experience consuming GraphQL APIs (e.g., Apollo Client), with an understanding of how to define and use types for API responses.
  • Strong understanding of web performance optimisation techniques.
  • Experience with version control systems (e.g., Git).
  • Excellent problem-solving skills and attention to detail.
  • Strong communication and collaboration abilities, especially when working within cross-functional teams spanning product, design, backend, and mobile engineering.
  • Living in Porto (hybrid role).
  • Fluent level of English.

We connect IT professionals with projects that match their skills, professional experience, and goals, then we offer a career progression program, delivered by in-house specialists - our People Experience Partners - to guide them through our journey with us.

What we offer:

  • A project that matches your skills and ambitions, as well as your preferences for working policies and culture.
  • A competitive salary with awesome benefits and opportunities to leverage your knowledge and network to earn additional income.
  • An empowering and respectful work culture enriched with social and learning events.
  • A People Experience Partner specially assigned to you - your go-to career guide, responsible for supporting your growth, facilitating training, and ensuring your work-life balance at KWAN.
At KWAN, they make sure that I feel comfortable with the client I’m working for and that what I’m doing aligns with my career aspirations.
Luis Caldeira, DevOps @ KWAN
At KWAN, I’m given the space to be myself and do what I love. I have control over the projects I work on, as well as the direction of my career.
Pedro Fonseca, Front End Developer @ KWAN
I see my People Experience Partner as someone who is always available to provide me with motivation and constant feedback, which helps me be sure that I am in the right place.
Josimar dos Reis, Software Developer @ KWAN
I know that I’ve contributed to the growth of a company that truly values a “people first culture”, because my ideas, experiences, and individuality were always appreciated.
João Nascimento, Software Developer (KWAN Alumni)
My two years at KWAN were an incredible experience! From the start, I was welcomed into a warm and collaborative environment where I felt truly supported.
Laís Ortiz, Software Developer @ (KWAN Alumni)
Grab this opportunity, apply now!

What You Can Expect as a KWANer

Respect isn’t optional here

You’re trusted to deliver and supported to speak up.

Dedicated People Experience Partner

Someone accountable for your growth, not your allocation.

Continuous learning, built in

Learning that keeps pace with the systems you build.

Recognition that’s visible

Your impact doesn’t go unnoticed. Through our Rocket Points System, we constantly recognize your contributions.

A culture you can feel

From movie and quiz nights to dinners and our annual summer gathering, we don’t just work together - we build real connections.

Flexible spaces to work your way

Remote-first, with physical hubs when you want connection.

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Tell Us About You

We review every application. If there’s alignment, we won’t let it get lost in a database.