Senior Software Engineer (Tech Lead)

Quick Facts

Role: Senior Software Engineer (Tech Lead) — Bidding Platform

Focus: High-performance, scalable, observable systems for real-time ad auctions and worldwide ad delivery

Work model: 100% remote or Warsaw/Cracow office

Contract: B2B

Description

You’ll join the Bidding Platform team, processing 20+ million requests per second to run real-time auctions and serve display ads to customers in 90+ countries. As a Tech Lead, you will design and drive implementations that deliver high performance, scalability, and observability, while building production-grade services and batch jobs. You’ll provide hands-on technical leadership through solving complex issues, planning and scoping, and participating in code reviews.

Responsibilities

• Design and lead implementations of system changes for high performance, scalability, and observability
• Build tools and optimizations to improve measurable critical user performance metrics
• Implement, test, deploy, monitor, and maintain HTTP/gRPC services and batch jobs in Java and Python (including environment setup and configuration code)
• Provide hands-on technical leadership: solve complex system challenges, support project scoping, and enforce coding standards via code reviews

Requirements

• Excellent understanding of complex IT systems from hardware to software to algorithms
• Very good knowledge of fundamental Internet protocols and technologies (DNS, HTTP, cookies)
• Good knowledge of concurrent programming and distributed systems (threads to geo-distributed clusters)
• Practical ability to observe, monitor, and analyze production systems
• Ability to critically analyze performance (theoretical estimates and production diagnostics)
• General knowledge of issues and troubleshooting methods for high scalability and high availability
• C1 level English and Polish
• Nice to have: experience in AdTech/Real Time Bidding and/or Real User Monitoring (RUM)

Benefits

• Extreme performance and high code quality (clean code and solid code reviews)
• Interdisciplinary, self-sufficient team collaboration with DevOps, database experts, backend developers, product designers, and QA
• Access to modern technologies and the opportunity to work on large-scale, high-impact projects
• B2B contract