Frontend Engineer

We're quickly growing and super excited for you to join us!

Today, Topsort has 6 major hubs worldwide, and employees in 13+ countries, including Menlo Park, Boston, Santiago Chile, São Paulo Brazil, Barcelona Spain, and Sydney Australia. We are a truly global company that was born in the pandemic that’s had rapid growth since out of a genius product, a customer‑first mentality, and a hardworking team of talented individuals. Since our founding in 2021, we’ve gained customers in retail, marketplaces, and delivery apps in 40+ countries and are quickly approaching the #1 position in the industry.

Do you enjoy a fast‑paced environment? Do you like seeing your work create real‑time impact, being part of a rocket ship from the very beginning? Let’s do the unimaginable — let’s make ads clean and cool again, with AI and modern technology.

Topsort is changing the way Retail Media works. By joining our scaling team, you'll feel your impact from day 1. The processes and messaging you build today will be a critical part of our foundation as we accelerate toward 200 Topsorters worldwide, and your innovations will leave a lasting mark on the industry, as a whole. Retail Media is on the verge of a new era, and Topsort is gathering the ecosystem together to shape a brighter future.

Joining us now, you'll work directly alongside our co‑founders and founding members to bring on Retail Media 3.0. If you're looking to define your career as something greater than yourself, come scale with us.

At Topsort, we communicate openly and move fast. We say things as they are, challenge each other early, and embrace feedback with curiosity—it’s how we build better, faster. Every experiment has a purpose, and every outcome helps us make the next decision smarter. There’s no single formula for success here; we find what works, improve it, and scale it.

We’re collaborative internally and competitive externally—never the other way around. The pace is quick, sometimes a 100‑mph kind of fast, and that’s what keeps it exciting. We act with intent, lift each other up, and turn bold ideas into real results. No endless meetings here—if it can be done today, it gets done today.

As a Senior Front‑End Developer at Topsort, you’ll be responsible for building and optimizing user‑facing features that power our platform, working closely with designers, product managers, and backend engineers to deliver seamless and responsive web experiences. You’ll work primarily with modern JavaScript frameworks like React (and ideally Next.js), focusing on performance, accessibility, and scalability. This role is ideal for someone who thrives in a fast‑paced startup environment, enjoys turning complex problems into intuitive interfaces, and takes pride in clean, maintainable code.

• Develop, maintain, and optimize front‑end components and user interfaces.
• Work closely with designers, product managers, and backend developers to implement new features.
• Ensure cross‑browser compatibility and responsive design for web applications.

We’re open to candidates who don’t check every box but show strong potential.

• Bachelor’s in Computer Science, Design, or related field.
• 2+ years of experience in front‑end development.
• Strong knowledge of JavaScript, HTML, CSS, and front‑end frameworks such as React.
• Proficiency in modern JavaScript frameworks (React, Vue.js, or similar).
• Experience with front‑end build tools and workflows (Webpack, Babel, NPM).
• Strong understanding of responsive design, accessibility, and web performance optimization.
• Preferred experience:
  
  Experience with Next.js or server‑side rendering (SSR). Contributions to open‑source projects or development of high‑traffic web applications.
• Availability to work 4 days a week onsite from our Somerville office.

• Demonstrated experience working in a three‑tier application architecture
• Experience working with Python frameworks like FastAPI
• Experience working with PostgreSQL

• Deep dive into details:
  Professionals who are not content…