Senior Backend Engineer

About Topsort
Topsort is redefining Retail Media by democratizing ad monetization with privacy-first, cookie-free, AI-powered technology. Our mission is to make advertising clean, intuitive, and genuinely effective, without creepy ads or outdated practices.

Founded in 2021, Topsort has grown rapidly and now operates across 6 global hubs with team members in 13+ countries. We work with retailers, marketplaces, and delivery apps in 40+ countries and are quickly becoming a global leader in the space.

Why Topsort? Why now?
This is a unique opportunity to join a fast-scaling, high-impact company where your work matters from day one. You’ll help shape the foundations of Retail Media 3.0, working closely with founders and early team members in a highly collaborative, fast-paced environment.

What it’s like to work at Topsort
We move fast, communicate openly, and value direct feedback. We experiment, learn, and scale what works—without unnecessary bureaucracy. If you enjoy autonomy, ownership, and seeing real-time impact, you’ll feel right at home at Topsort.

What Is This Role Like?
As a Senior Engineer at Topsort you will build back-end services, APIs, and front-end experiences to support our mission: democratizing auction-based infrastructure for all marketplaces. Our first product is sponsored listings as a service. We automate and simplify auctions so that any advertiser, especially small ones, can compete successfully. It’s not easy. We use our game and auction theory expertise; implement real-time, scalable, always-available systems; and build an intuitive, easy-to-use UI for managing campaigns.

In this role, you will:

• Design, develop, and maintain scalable, high-performance applications while ensuring code quality and best practices.
• Provide mentorship, conduct code reviews, and drive best engineering practices to improve team efficiency.
• Identify and resolve bottlenecks, optimize system performance, and ensure reliability in distributed architectures.
• Work with cross-functional teams, translate business needs into technical solutions, and drive innovation through new technologies and best practices.

What We Think You Need to Be Successful - we’re open to candidates who don’t check
every box but show strong potential!

Core Requirements & Experience:

• Bachelor’s or Master’s degree in Computer Science, Engineering, or a related field.
• 5+ years of experience in backend engineering, designing, developing, and maintaining scalable services.
• Strong experience with microservices architecture and distributed systems, ensuring efficiency and reliability.
• Proven track record of implementing engineering best practices, improving development efficiency and maintaining high code quality.
• Proficiency in Python and TypeScript, with a solid understanding of best practices, patterns, and performance optimization.
• Expertise in high-performance, low-latency systems, designing solutions that scale efficiently.
• Deep knowledge of distributed systems, decoupling patterns, and modern software architecture to build robust and maintainable services.
• Strong problem-solving and collaboration skills, working closely with product and engineering teams to develop new features and optimize existing ones.

Bonus Points
- Experience in B2B SaaS, ad-tech, martech, or data platforms.
- Familiarity with retail, marketplaces, or media monetization.
- Fluency in additional languages beyond English.

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.