Senior Big Data Engineer (AdTech Cybersecurity)

Are you passionate about building scalable Big Data solutions and optimizing high-load platforms? We are looking for a Senior Big Data Engineer to join a long-term project in the cybersecurity and AdTech domain focused on real-time risk assessment for digital advertising ecosystems. We at Sigma Software offer the opportunity to work on impactful products, collaborate with experienced engineering teams, and contribute to solutions operating on large-scale datasets in a fast-paced environment. You will have the freedom to influence technical decisions and drive meaningful improvements across the platform. CUSTOMER Our Customer operates in the cybersecurity domain and develops solutions aimed at protecting organizations and digital ecosystems from online risks and vulnerabilities. The company focuses on building advanced technologies that improve security, reliability, and operational resilience across various industries. PROJECT The project is a real-time risk assessment platform for digital advertising ecosystems. The solution helps customers identify potentially low-quality or fraudulent traffic and automatically make decisions before allocating advertising budgets. The platform processes large-scale data streams and requires continuous improvements in performance, scalability, and cost efficiency. At the initial stage, the role will focus on Snowflake optimization and identifying inefficiencies in data pipelines and SQL queries. In the long term, the engineer will contribute to backend development, platform architecture improvements, and implementation of scalable Java-based services. Optimize Snowflake usage and improve infrastructure cost efficiency Identify inefficiencies in data pipelines and SQL queries Implement performance and cost optimization improvements Enhance and maintain Java-based services Implement and support new platform features Improve existing engineering processes and platform components Develop scalable and reliable solutions for high-load environments Contribute to architecture improvements and implementation of new components Collaborate with distributed engineering teams to deliver stable platform functionality At least 5 years of commercial experience in Big Data engineering Strong hands-on experience with Snowflake Strong expertise in Python Strong expertise in Java Advanced SQL knowledge and experience optimizing complex queries Solid Computer Science fundamentals Upper-Intermediate or higher English level WILL BE A PLUS Experience with AWS cloud services Experience working with Amazon S3 Experience in AdTech, cybersecurity, fraud detection, or risk assessment domains PERSONAL PROFILE Proactive and ownership-driven mindset Strong analytical and troubleshooting skills Ability to work effectively in fast-paced environments Team-oriented communication style Focus on scalable and maintainable engineering solutions