Staff/Sr. Software Engineer, Performance Testing Platform

The Performance Team within Developer Experience builds the infrastructure that lets developers test, measure, and trust the performance of Apples search capabilities before they ship. Were looking for an experienced software engineer to help build and scale a performance testing platform used across the org - one that gives developers confidence that results measured in a dev environment reflect what will happen in production. Youll work closely with product and information intelligence teams to deliver infrastructure thats reliable, scalable, and efficient, powering Apple products for billions of users. We build the infrastructure that lets developer teams across Search test, measure, and validate the performance of features before they reach billions of Siri users. Our platform captures and replays production-scale traffic so developers can load-test changes in a dev environment and trust that the results are indicative of production behavior. We apply statistical analysis to model how latency, throughput, and resource usage shift from dev to production, helping teams catch performance regressions before they ship. Youll have the opportunity to work with systems processing massive volumes of traffic and results data, with a scale and complexity few teams encounter.Design, develop, and operate the performance testing platform that lets developers across Search load-test and validate infrastructure changes before they reach production Build and improve traffic capture/replay and load-generation tooling, along with the pipelines that process the resulting performance data at scale Apply statistical analysis to project how performance results measured in dev environments will translate to production, and to detect regressions before rollout Collaborate closely with product, search, and information intelligence teams to define infrastructure requirements and deliver robust solutions Ensure the health and performance of critical infrastructure by monitoring key metrics, troubleshooting complex issues, and participating in an on-call rotation10+ years of experience in software development, including designing, building, and operating large-scale distributed systems and backend infrastructure Solid understanding of networking protocols (e.g., TCP/IP, DNS, HTTP) and their application in large-scale systems Strong software engineering fundamentals in data structures, algorithms, and system design Excellent communication and collaboration skills to work effectively with cross-functional teams BS, MS, or Ph.D. in Computer Science or a related field, or equivalent experienceStatistical/analytical experience projecting how dev-environment results map to production behavior (regression analysis, capacity modeling) Hands-on experience designing load test frameworks: traffic capture/replay, configurable load shapes, concurrency control Experience with observability tooling for root-causing performance regressions Familiarity with Kubernetes, workflow orchestration and CI/CD pipelines for automating test infrastructure