About The Position
Apple Ads helps developers and businesses reach customers on the App Store through highly relevant, privacy-focused advertising. Our engineering teams build the infrastructure that powers ad delivery at Apple scale — from search and retrieval to auction, ranking, and measurement. We are looking for a Software Engineer to join the team responsible for Apple Ads' core search and indexing platform — the system that retrieves the most relevant ad candidates in response to real-time search queries across our ad placements. This platform operates at massive scale, handling tens of thousands of requests per second with strict latency requirements, and indexes millions of advertiser campaigns with complex targeting signals. We are investing heavily in evolving this platform: transitioning from batch-based architectures to streaming-first, near-real-time indexing, building modular retrieval infrastructure that scales efficiently across multiple ad placements, and introducing on-device ML scoring at retrieval time. You will have the opportunity to work across the full search stack — from index construction pipelines and data ingestion, to query execution, candidate ranking, and production reliability.
Requirements
- 3+ years of software engineering experience with a focus on backend or distributed systems
- Strong programming skills in one or more of: Rust, C++, Java, or Scala
- Deep understanding of search and information retrieval fundamentals — inverted indexes, posting lists, forward/reverse index construction, tokenization, query parsing, and sharding
- Hands-on experience building and operating high-throughput, low-latency distributed services with tight SLA requirements
- Experience with streaming data infrastructure such as Apache Kafka, Amazon Kinesis, or equivalent systems
- Familiarity with container orchestration (e.g., Kubernetes) and operating services in large-scale cloud environments
Nice To Haves
- Experience with embedding-based retrieval (EBR) or approximate nearest neighbor (ANN) search systems
- Background in advertising technology — ad serving, candidate retrieval, auction systems, bid resolution, or L1/L2 ranking pipelines
- Experience deploying ML models in latency-sensitive inference environments, including feature serving and model lifecycle management
- Familiarity with A/B experimentation platforms and offline evaluation pipelines for ranking and retrieval
- Experience designing and migrating systems from batch-only to streaming-first architectures
- Track record of improving developer tooling and code quality in large, collaborative codebases — including test coverage automation, schema management, and CI/CD pipeline improvements
Responsibilities
- Design, build, and maintain large-scale distributed search and indexing systems that power real-time ad retrieval
- Develop streaming index pipelines that reflect advertiser campaign changes in near-real-time, replacing legacy batch-only workflows
- Build and optimize retrieval components including inverted indexes, approximate nearest neighbor (ANN/EBR) indexes, query tree generation, and candidate ranking at the leaf level
- Implement ad eligibility and filtering logic at retrieval time — including keyword matching, audience targeting, budget enforcement, frequency capping, and policy compliance
- Drive platform generalization — abstracting core retrieval capabilities (matching, eligibility, scoring, ranking) into a shared base stack that new ad placements can build on without rebuilding from scratch
- Build auto-scaling infrastructure to eliminate manual capacity operations and support organic demand growth
- Develop observability and debugging tooling to give engineers real-time visibility into index state, query behavior, and candidate retrieval outcomes
- Contribute to offline experimentation infrastructure that allows ML teams to evaluate new ranking and matching models without risk to production traffic
- Participate in on-call rotations and lead incident response for production search and indexing systems
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What This Job Offers
Job Type
Full-time
Career Level
Mid Level
Education Level
No Education Listed
