Senior Fullstack Web Performance Engineer (AdTech)

TL;DR

Senior Fullstack Web Performance Engineer (AdTech): Designing and implementing high-performance frontend and full-stack solutions for global ad display and tracking with an accent on extreme scalability and observability. Focus on optimizing critical user performance metrics, building RUM monitoring systems, and resolving complex system bottlenecks.

Location: Poland (Remote or Hybrid in Warsaw/Cracow)

Company

Global company providing deep-learning powered marketing technologies for top brands and agencies worldwide.

What you will do

• Design and lead implementation of high-performance, scalable, and observable systems for global ad display and tracking.
• Implement frontend and full-stack solutions focusing on extreme performance and scalability.
• Develop RUM and Synthetic monitoring systems to diagnose and resolve performance bottlenecks.
• Collaborate with Ads Layout specialists and backend engineers for optimal architectural alignment.
• Write and deploy efficient code in JavaScript, TypeScript, Python, and Java.
• Provide technical leadership through project scoping and high-standard code reviews.

Requirements

• 8+ years of software engineering experience with deep understanding of Frontend internal mechanisms.
• Strong expertise in Web Performance optimization and advanced loading strategies (caching, asset delivery).
• Proficiency in JavaScript, TypeScript, React, and build tools (Webpack, Vite).
• Deep knowledge of Internet protocols (DNS, HTTP, cookies).
• Ability to monitor and analyze production systems to derive actionable conclusions.
• C1 level in English and Polish required.

Nice to have

• Experience in AdTech or Real Time Bidding (RTB).
• Experience contributing to Real User Monitoring (RUM) systems.

Culture & Benefits

• Focus on extreme performance, clean code, and rigorous code reviews.
• Interdisciplinary team collaboration with DevOps, DB experts, and Product Designers.
• Access to modern technologies in large-scale, high-impact projects.
• Cooperation based on B2B contract.
• Flexible work arrangement: 100% remote or office-based in Warsaw or Cracow.