SeniorJavaDeveloper-DSP(PurchaseLoop)

Are you interested in working with cutting-edge technologies and developing high-performance applications capable of handling over 2 million data queries per second? If so, we have the perfect job for you at LoopMe! We are a team of skilled engineers who develop and maintain real-time bidding platforms for global advertisers. As part of our team, you will work alongside other talented engineers on a daily basis, using technologies such as Java, Postgres, Clickhouse, Kafka, and others to scale performance, optimize cloud infrastructure, and create innovative features for our various product lines. At LoopMe, we follow Agile methodology to deliver features rapidly to the market. Join us and be a part of our mission to push the boundaries of what is possible in the advertising industry! **What we need** We are looking for a Senior Java Backend Engineer to help build out our high-load ad serving system, capable of handling over 2M requests/second under 50ms response time. **What you'll be doing** * Developing features and performance optimisation for our Java ad-serving application * Implementing complex targeting algorithms developed by our data science team into the core ad-serving flow * Implementing backend for BI ad-hoc queries **Must have skills** * Java 17+ (Spring Boot, Gradle) * REST API design and implementation * SQL (PostgreSQL) + experience with schema migrations * Experience with microservices architecture * Production experience with GCP or similar cloud platform Strong testing practices (unit + integration **Nice-to-have** * GraphQL (consumer or provider side) * OpenRTB / ad tech domain knowledge * Kubernetes / GKE * Experience with event-driven systems * AI/agentic coding tools (Claude Code, Copilot) **Soft skills** * Can operate independently on ambiguous problems * Comfortable working with a distributed team (Ukraine, Poland, UK) * Willing to mentor mid-level BE devs ** Benefits:** * Competitive compensation package * Flexible working schedule and the