Principal/Senior Backend Engineer

Are you ready to take on a high-impact role in building cutting-edge advertising technology? We are looking for a Principal/Senior Backend Engineer to join our team and design a high-load, low-latency real-time bidding platform. This position is based in Warsaw, Poland, with the flexibility to work remotely.

At Sigma Software, we deliver innovative, scalable solutions that empower industries and drive measurable results. You will work alongside talented professionals in a culture that values expertise, collaboration, and continuous growth.

Why join us? We offer competitive benefits, flexible working arrangements, and opportunities to work on challenging projects that push the boundaries of technology.

CUSTOMER

Our customer is a globally recognized technology-driven company operating in the digital advertising space. They specialize in delivering scalable, high-performance solutions that empower advertisers to optimize campaigns in real time. With a strong culture of innovation and excellence, they are committed to building platforms that shape the future of programmatic advertising.

PROJECT

The project is a strategic self-service advertising solution designed to make streaming inventory more accessible, measurable, and performance-driven for advertisers of all sizes. It includes a real-time bidding and optimization platform capable of handling high-load, low-latency auction mechanics. The system integrates forecastin

• Design and implement core backend services for real-time bidding, optimization, and ad delivery workflows
• Build custom bidding agents for real-time bid decisioning
• Develop high-load, low-latency components supporting real-time auction and delivery mechanics
• Implement proprietary pacing, bid-shading, and optimization logic to improve campaign efficiency
• Design and integrate forecasting capabilities for impressions, reach, outcomes estimation, and campaign planning
• Work with OpenRTB, JSON, protobuf, and other ad-tech protocols and data formats
• Integrate with data and metrics pipelines to support real-time optimization and reporting
• Implement observability, monitoring, and troubleshooting capabilities (LGTM/ELK stack)
• Collaborate with product, engineering, data, and ad operations stakeholders to deliver scalable performance advertising capabilities

• 5+ years of relevant experience as a Backend Engineer in commercial projects
• Strong backend engineering experience with C++ or Golang
• Experience designing and building high-load, low-latency distributed systems
• Hands-on experience with JSON-based integrations, protobuf, or similar protocols
• Experience with low-latency data stores and caching technologies (Aerospike, Redis, ElastiCache, etc.)
• Experience with PostgreSQL or similar relational databases
• Proven track record of building production-grade services with strong reliability, scalability, and observability requirements
• Ability to work independently, reason through complex system trade-offs, and contribute to architecture decisions
• Upper-Intermediate English level

WILL BE A PLUS

• Understanding of real-time bidding systems, auction mechanics, and ad-tech domain
• Knowledge of pacing, bid optimization, forecasting, or performance advertising delivery mechanics
• Experience working on DSP, SSP, ad exchange, ad server, or performance marketing platforms
• Familiarity with LGTM/ELK or similar observability stacks

PERSONAL PROFILE

• Analytical mindset with strong problem-solving skills
• Ability to work in fast-paced environments
• Excellent communication skills for cross-team collaboration
• Self-motivated and proactive approach to work
• Strong attention to detail and commitment to quality