Senior Frontend Engineer

Who we are

At Fluxon, we believe that how you build matters as much as what you build. We help businesses navigate their most important technology decisions with confidence, and take responsibility for seeing them through. Founded by ex-Googlers and startup veterans, we’re proud to partner with teams behind some of the most ambitious products, including Google, OpenAI, Anthropic, Walmart and Stripe. 

Our work spans strategy, design, and engineering — often in complex, AI-driven environments — where clarity, speed and quality are the standard. We use AI intentionally, applying it only where it adds real value and expands what’s possible. Care shapes everything we do.

Inside Fluxon, you’ll find a global, remote-first team of experienced builders, who are curious, kind and serious about their craft. We’re building a place where people can take ownership, solve problems that matter and do work they’re proud to stand behind. If you want to do your best work alongside people who care as much as you do, you’ll feel at home here.

Note: This position is fully remote with a strong preference for a candidate based in Portugal (Lisbon). 

About the role

As a Senior Frontend Engineer at Fluxon, you’ll create and deliver beautiful user experiences for our clients.

You’ll be responsible for building and iterating on software from design to launch by:

• Clarifying requirements and UI design in partnership with our Product and Design teams
• Collaborate closely with designers to ensure a high level of UX polish and interaction quality in everything you build
• Breaking down goals into achievable tasks and following sprint timelines effectively
• Proactively communicating progress and challenges in your work
• Learning fast and working independently and reliably
• Following best practices in frontend development, including efficient component architecture, responsive design patterns, state management best practices, comprehensive unit/integration testing, and optimizing for performance and accessibility
• Implement meaningful motion and microinteractions that enhance usability and delight

Technologies we frequently work with include:

• Frameworks
• Next.js, React, Angular, Vue.js
• Programming
• Typescript/JS, CSS
• Styling
• Tailwind CSS, Material UI, Chakra UI, Shadcn
• Design Tools
• Figma
• State Management
• Redux, Zustand, Jotai
• Mobile Development
• React Native/Expo, Progressive Web Apps (PWAs)
• Backend Integration
• REST APIs, GraphQL, WebSockets

Qualifications

• 6+ years of professional experience in frontend development
• Fluency in TypeScript/JavaScript, HTML, CSS, and modern web development practices
• Expertise with at least one modern frontend framework (React, Angular, or Next.js) with a passion for continuous learning
• Experience in building highly-performant and scalable web applications
• Strong understanding of responsive design and mobile-first approaches
• Strong sense of UX and interaction design
• Proactive, can-do attitude with a creative approach to problem solving
• Comfortable in a client-facing consulting role
• Experience with Design Systems and building accessible products is a plus

What we offer

• Remote-first, flexible work with a budget to set up a work space that works for you
• Localized healthcare coverage to support you and your family’s wellbeing
• Flexible paid time off with a minimum of 3 weeks per year (plus holidays)
• "No internal meetings" Fridays, so you can focus on deep, uninterrupted work
• A professional growth budget for learning that matters to you –  whether it’s developing your technical skills or learning a new language
• A monthly wellness allowance to support your physical and mental health
• Annual company offsites, where we gather in person to build meaningful connections
• A competitive salary that reflects your expertise, impact and experience
• Profit-sharing, so you can benefit directly from the value we build together
• A paid sabbatical program, designed for rest, renewal and fresh perspective