Senior Frontend Engineer

Were quickly growing and super excited for you to join us!

About Topsort

At Topsort we believe in the mission of democratizing the secret technologies of the walled gardens and creating a privacy-first cookie-free world of clean advertising with modern tech friendly products and AI. We believe in making advertising intuitive intelligent and genuinely cool without any of the creepy ads or cookie-obsession (well maybe just the chocolate ones). In a rapidly changing industry were on a mission to democratize monetization access for all and ensure that advertising doesnt leave any brand or seller feeling confused or overwhelmed

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 thats 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 weve 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 Lets do the unimaginable - lets make ads clean and cool again with AI and modern technology.

Why Topsort Why now

Topsort is changing the way Retail Media works. By joining our scaling team youll 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 youll work directly alongside our co-founders and founding members to bring on Retail Media 3.0. If youre looking to define your career as something greater than yourself come scale with us.

What its like to work at Topsort

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

Were collaborative internally and competitive externallynever the other way around. The pace is quick sometimes a 100-mph kind of fast and thats what keeps it exciting. We act with intent lift each other up and turn bold ideas into real results. No endless meetings hereif it can be done today it gets done today.

What is this Role like

As a Senior Front-End Developer at Topsort youll 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. Youll work primarily with modern JavaScript frameworks like React (and ideally ) 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.

What you will do at Topsort:

• 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.

What We Think You Need to Be Successful

Were open to candidates who dont check every box but show strong potential.

Core Requirements & Experience

• Bachelors in Computer Science Design or related field.
• 5 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 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 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.

Bonus Points

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

What We Value

At Topsort we seek professionals who embody the following qualities to drive our mission forward:

• Deep dive into details:Professionals who are not content with superficial answers and dive deeply into the details to uncover root causes and optimal solutions.
• Team first:A low need for individual recognition always prioritizing collective results over personal credit.
• You thrive with ambiguity:Exceptional ability to tackle open-ended problems in unstructured environments turning chaos into structured innovation.
• Adaptability:Willingness to learn mentor lead and follow as the situation demands fostering growth at all levels.
• Urgency:A disproportionate sense of urgency in execution while keeping scalability and the creation of replicable processes in mind to ensure long-term success.
• Curiosity:Genuinely curious individuals who can quickly learn difficult concepts and apply them effectively.

Do you sound like the right fit Lets dive right in!