Java Backend Engineer

About LoopMe LoopMe is an AI company solving one of advertising's hardest problems: making brand advertising actually measurable — and making it perform. Our platform runs patented machine learning models across billions of consumer signals in real time, optimising campaigns toward outcomes like purchase intent, brand lift, and foot traffic rather than proxy metrics like clicks. The result is 2–5x better performance than industry benchmarks, at scale. We operate a high-load programmatic infrastructure — processing millions of ad requests per second with sub-200ms response times globally. This isn't a layer on top of someone else's stack; it's built from the ground up, in-house, by the team you'd be joining. Founded in 2012 and headquartered in London, we now have 400+ people across 19 cities and have sustained 40% revenue CAGR since 2018. The engineering problems here are real, the ownership is genuine, and the scale is significant. The opportunity You'll build and scale LoopMe's Data Management Platform — a massively distributed, high-throughput system processing billions of events daily, creating rich device and audience profiles, and exporting data segments to 50+ global partners and exchanges in real time. This is backend engineering at genuine scale: complex data pipelines, real-time processing, and the infrastructure powering large-scale advertising auctions and audience targeting. This role sits within the DMP engineering team. What you'll do Develop features and optimise performance for large-scale data pipelines built on Spark, HBase, and Kafka Design and optimise data schemas for relational and NoSQL databases Build and maintain microservice applications across a large multi-module codebase Own your work end to end — from design through to production delivery What you'll bring Essential: 2+ years of backend engineering experience Proficiency in Java with a strong understanding of concurrency and distributed systems Experience with Spring Framework or a comparable IoC framework Experience with JPA or another ORM framework Strong SQL skills and experience with PostgreSQL or a modern RDBMS Nice to have: Experience with Apache Spark or another large-scale data processing framework Familiarity with HBase or other NoSQL/columnar stores Experience with Kubernetes and Kafka Experience integrating AI or LLM capabilities into backend services What we offer Hybrid working Flexible schedule 1 month work-from-anywhere Annual performance bonus Multikafeteria (sport/culture card) LoopMe Gives Back Learning & development support