Senior Software Engineer - Activation APIs

About the role

Our platform is the foundational identity and data layer for 900M+ monthly active users, serving 2.5B+ profiles at massive scale. We are building a predictive, identity-centric insights engine-ensuring our audience is understood with precision to deliver hyper-personalized experiences and advertising solutions across all our digital properties. Our mission centers on first-party data strategy: capturing, enriching, and activating audience signals to build a 360-degree view of every user. We operate under a Privacy-by-Design philosophy, adhering to global regulations (GDPR, CCPA) and industry security standards, while leveraging a cloud-native stack across GCP (BigQuery, Spanner, Dataflow, Composer, GKE) and AWS, with modern MLOps practices to deliver measurable business impact. As a Senior Software Engineer, you will build and optimize high-performance production APIs that serve millions of requests per second with sub-10ms latency. These APIs are critical infrastructure enabling our personalization and advertising systems to access the 2.5B+ profile dataset in real-time, directly impacting hundreds of millions in annual revenue and user experience quality. You will develop API endpoints integrating with downstream systems and applications, ensuring reliable, low-latency access to user profile data, audience segments, and enrichment signals. Your work requires balancing extreme performance requirements (sub-10ms p99 latency) with data privacy compliance, cost efficiency, and production reliability at massive scale. This role demands deep expertise in high-performance API development, distributed caching strategies, and production systems engineering. You will collaborate closely with Product, Data Platform, and Infrastructure teams while taking ownership of critical API components that serve as the backbone of our data activation strategy.