Senior Fullstack Developer (AdTech)

TL;DR

Senior Fullstack Developer (AdTech): Building and optimizing core features for a Big Data/AI audience intelligence platform with an accent on backend service architecture and audience-activation layers. Focus on modernizing system components, ensuring high performance, and mentoring the development team.

Location: Must be based in Warsaw (Poland), Serbia, or Romania

Company

A global staffing company providing talent for a large-scale advertising technology firm that develops audience intelligence and campaign automation tools.

What you will do

• Plan, implement, and own core features across backend services including audience targeting and management APIs.
• Collaborate with Product, TSE, and DevOps teams on system design and architecture.
• Develop the audience-activation layer connecting data to downstream TV, streaming, and commercial systems.
• Refactor system components and modernize the tech stack to enhance stability and performance.
• Lead and mentor developers on complex, cross-service projects.

Requirements

• 6+ years of software development experience.
• At least 3 years of backend development experience with Ruby, Java, Python, or Node.js.
• Proficiency in HTML, CSS, JavaScript, and modern UI frameworks like React.
• Experience with both relational and non-relational databases.
• Familiarity with Linux environments.
• Excellent communication skills with fluency in English.

Nice to have

• BSc in Computer Science or equivalent.
• Professional experience with Ruby.
• Professional experience with React.

Culture & Benefits

• Opportunity to work on a global-scale Big Data and AI platform.
• Collaborative environment with cross-functional teams.
• Professional growth through mentoring and complex project ownership.
• Global staffing support with detailed benefit packages available upon contact.