Senior/Principal Golang Developer

JobCubby; Warszawa; Hybrid; PLN 260,000 - 360,000; Full time

Job summary

Sigma Software is seeking a Senior Golang Backend Engineer to join a cross-functional team delivering cutting-edge AdTech and cybersecurity solutions. You will design, develop, and maintain high-performance backend services in Golang, and contribute to building scalable, low-latency systems used by major internet platforms.

You will collaborate with data scientists, malware analysts, researchers, and product managers to improve scalability, reliability, latency, and cost efficiency across

Qualifications

• 5+ years of commercial software development experience.
• Strong commercial experience with Golang and backend engineering.
• Strong CS fundamentals including algorithms, data structures, concurrency, and system design.
• Proven experience with high-load distributed systems.
• Experience with performance tuning, latency optimization, and memory management.
• Hands-on experience with Kubernetes, Terraform, and Helm Charts.
• Good understanding of DevOps practices and cloud-native deployments.
• Experience with SQL databases and large-scale data processing.
• Experience working with AI tools, LLMs, or agent-based systems.
• Product-oriented mindset and ability to align technical solutions with business goals.
• Experience across the full software development lifecycle.
• Ability to design stable, maintainable, and scalable architectures.
• Availability to work with flexible hours and maintain 3–4 hours overlap with EST time zone.
• Upper-Intermediate English level or higher.

Responsibilities

• Design, develop, and maintain high-performance backend services in Golang.
• Build and optimize distributed systems processing trillions of prediction requests daily.
• Collaborate with data scientists, malware analysts, researchers, and product managers.
• Improve system scalability, reliability, latency, and cost efficiency.
• Develop, test, review, deploy, and maintain software across multiple environments.
• Ensure software quality through clean architecture and engineering best practices.
• Contribute to backlog prioritization and technical planning.
• Deploy and support services in Kubernetes environments.
• Investigate fraudulent activities and develop new fraud prevention approaches.
• Drive engineering excellence within a collaborative product-oriented team.

Skills

Golang

Backend engineering

Distributed systems

Performance tuning

Kubernetes

Terraform

Helm charts

DevOps

SQL databases

AI tools/LLMs

Tools

Kubernetes

Terraform

Helm

Apache Airflow

Job description

Company Description

Ready to build systems operating at internet scale and fight sophisticated digital fraud in real time? We are looking for a Senior Golang Backend Engineer to join a cross-functional team developing cutting-edge AdTech and cybersecurity solutions.

In this role, you will work with high-load distributed systems processing over 1.5 trillion prediction requests daily while collaborating with data scientists, malware analysts, and product experts. You will contribute to building scalable fraud prevention technologies used by major internet companies worldwide.

We at Sigma Software offer the opportunity to work on impactful global products, solve complex engineering challenges, and grow alongside experienced professionals in a collaborative and innovation-driven environment. Work format and location are flexible depending on your preferences and project needs.

CUSTOMER

Our Customer is a global cybersecurity company delivering advanced protection solutions for individuals, organizations, and digital ecosystems. The company specializes in large-scale threat detection, digital risk mitigation, and real-time protection technologies designed to combat sophisticated online threats across multiple industries.

PROJECT

The project focuses on building a real-time risk assessment platform for the digital advertising ecosystem. The solution helps identify invalid, fraudulent, or low-quality traffic before advertising budgets are spent, enabling automated decision-making in real time.

The team develops advanced fraud detection technologies integrated with major AdTech platforms, agencies, and brands. Engineers work closely with researchers and analysts to uncover abuse patterns, reduce sophisticated invalid traffic (IVT), and improve transparency across programmatic advertising systems.

Job Description

• Design, develop, and maintain high-performance backend services in Golang
• Build and optimize distributed systems processing trillions of prediction requests daily
• Collaborate with data scientists, malware analysts, researchers, and product managers
• Improve system scalability, reliability, latency, and cost efficiency
• Develop, test, review, deploy, and maintain software across multiple environments
• Ensure software quality through clean architecture and engineering best practices
• Contribute to backlog prioritization and technical planning
• Deploy and support services in Kubernetes environments
• Investigate fraudulent activities and develop new fraud prevention approaches
• Drive engineering excellence within a collaborative product-oriented team

Qualifications

• 5+ years of commercial software development experience
• Strong commercial experience with Golang and backend engineering
• Strong Computer Science fundamentals including algorithms, data structures, concurrency, and system design
• Proven experience with high-load distributed systems
• Experience with performance tuning, latency optimization, and memory management
• Hands-on experience with Kubernetes, Terraform, and Helm Charts
• Good understanding of DevOps practices and cloud-native deployments
• Experience with SQL databases and large-scale data processing
• Experience working with AI tools, LLMs, or agent-based systems
• Product-oriented mindset and ability to align technical solutions with business goals
• Experience across the full software development lifecycle
• Ability to design stable, maintainable, and scalable architectures
• Availability to work with flexible hours and maintain 3–4 hours overlap with EST time zone
• Upper-Intermediate English level or higher

WILL BE A PLUS

• Experience with Apache Airflow
• Experience with Python
• Experience with Snowflake
• Experience in the AdTech domain
• Experience with C++

Additional Information

PERSONAL PROFILE

• Strong analytical and problem-solving mindset
• Ownership mentality and proactive approach
• Ability to work effectively in a cross-functional environment
• Passion for scalable and high-quality systems
• Ability to balance technical excellence with business priorities
• Comfortable working in a fast-paced product environment