Lead Frontend Developer

Freeday; Randstad; On-site; EUR 70,000 - 90,000; Full time

Job summary

A tech scale-up in the Netherlands is seeking a Lead Frontend Developer to take ownership of our frontend technology. You will define the architecture, build key features using React and TypeScript, and elevate team standards. Ideal candidates have experience with modern frontend practices and can mentor others. Your role centers around ensuring high-quality user experience in an AI-driven environment, while also collaborating closely with design and backend teams. Join a team that values ownership, speed, and honest communication.

Qualifications

• Deep experience with React and TypeScript.
• You've made architectural decisions with trade-offs.
• Strong sense of design and UX.

Responsibilities

• Own the frontend architecture and tooling.
• Build features and interfaces with React and TypeScript.
• Mentor other developers and give feedback.

Skills

React

TypeScript

Modern frontend tooling

User experience (UX)

Mentoring

Job description

At Freeday, we believe technology should feel effortless. We're building digital employees that take over repetitive tasks, so humans get to do what we're actually good at: solving problems, being creative, working together. Our product only works if people enjoy using it. If it feels well thought-out, fast, and designed with care. That's where you come in.

We're looking for a Lead Frontend Developer who doesn't just build great interfaces, but who shapes how we build them. Someone who has strong opinions on code quality, architecture and user experience, and who makes the people around them better.

What you'll do here

You’ll own the frontend. Not in a "gatekeeper" way, but in a "this person sets the standard" way. You’ll be the one who makes sure our interfaces aren't just functional but crafted. You’ll work closely with designers, backend engineers and product to turn complex AI-powered functionality into something that feels simple and trustworthy.

Concretely, that means:

• Define and evolve our frontend architecture, tooling, and best practices
• Build key features and interfaces with React and TypeScript
• Own code quality, through reviews, standards, and leading by example
• Mentor other developers, give honest feedback, and help the team grow technically
• Translate design into smooth, responsive experiences — and push back on design when something can be better
• Make technical decisions about how we build the frontend and why
• Collaborate with product and design from the earliest stage of shaping ideas, not just at implementation time
• Build frontend first, you pave the way and define what the backend should provide, closely working with backend developers to get the best results.
• Help us figure out what "great frontend engineering" looks like as we scale

This is an AI-first product. The frontend isn't a skin on top of an API, it's where users experience the intelligence behind our digital employees. You’ll help define how adaptive interfaces, smart defaults, and streaming AI interactions actually feel to use.

There's also room to go deeper into the backend if you're curious. We run Django and Python, if you like understanding how things connect end to end, that's welcome.

Who we're looking for

You’ve been building with React and TypeScript for a while and you’ve seen what good looks like, and what doesn't. You’ve worked in teams where you had real influence on how things were built, not just what was built. You care about the craft, but you also know when to ship.

More specifically:

• Deep experience with React, TypeScript, and modern frontend tooling
• You've made architectural decisions and can explain the trade-offs
• You've mentored developers, through code reviews, pairing, or just being the person people go to when they're stuck
• Strong sense of design and UX, you notice when something is off and you do something about it
• You're direct. You'll challenge a design, question a technical approach, or flag when something isn't good enough
• You've worked in small, collaborative teams where you couldn't hide behind process
• You're curious about AI and excited about building interfaces for things that don't have established patterns yet

What this isn't

This isn't a people management role (at least not right now). You won't be leading performance reviews, though you might help out when it makes sense. You'll have 1:1s, we all do, that's just how we work. But your leadership shows up in the code, the standards you set, and how you elevate the team's work. If that grows into something more formal over time, we're open to that, but it starts with technical leadership.

Who we are

We're a Rotterdam-based tech scale-up. About 25 people, growing, with real customers and real revenue. We work from the office most of the time because the best ideas happen when people are in the same room. Not through endless meetings, through quick conversations, whiteboard sessions, and building things together.

No big egos. No politics. Just a team of people who like making smart things and helping each other get better.

What we value

• Delivering value fast, but not sloppy
• Taking ownership, of your work, of the team's output
• Being direct and honest, even when it's uncomfortable