Data Infrastructure Engineer (Query Engine)

About zaimler zaimler is building the platform that enables enterprises to create and maintain their operational context layer that powers their AI and data products. Our platform links fragmented enterprise data, extracts meaning with knowledge-distilled models, manages context and sits in the execution path, querying live data. We’re creating the foundation for AI systems that don’t just generate, but retrieve, link, and reason over enterprise knowledge. In just over a year, we’ve begun partnering with Fortune 500 design partners in insurance, finance, asset-management, and technology, deploying our semantic platform into some of the world’s most complex and high-volume data ecosystems. Our platform enables enterprises to make their data AI-ready from the start: link across clouds and lakes, automatic ontology creation, data mapping, and federated retrieval-augmented reasoning at scale. Our team comes from LinkedIn, Visa, Meta, and Branch, and has spent decades solving data and infrastructure challenges at scale. Backed by top VCs, we’re building the operational context layer powering the future of enterprise AI. What You’ll Do zaimler's query engine powers graph-native queries across a two-layer system: an internal storage and indexing layer, and a pass-through layer that queries live into customer data platforms like Snowflake, Databricks and Oracle. You'll work across the engine's coordinator, compiler, and executor, extending language and function support, and helping build queries that reason and aggregate across multiple data sources at once. What You'll Own Extend the query engine's language and function support over time Help build cross-source query capabilities: answering questions that span multiple data sources in a single query Work on the storage and indexing layer that the query engine runs against Build and maintain the layer that queries live into external systems like Snowflake and Databricks Work directly in the engine's core components: coordinator, compiler, executor Work on query optimization and aggregations that spans multiple data sources Prior Experience Strong database fundamentals: you understand consistency models, transactions, and how storage layers actually work under the hood, not just how to query one Ordered key-value stores. FoundationDB or similar (TiKV, RocksDB-backed systems): designing index layouts, range scans, and transaction limits. Experience running systems at real production scale, where naive approaches start to break down A systems mindset: background in OS, file systems, distributed systems, or database internals, from industry or research Federated or distributed queries. Cross-source joins, filter and projection pushdown, semi-join and key-seeded lookups, cost-based join ordering, and late materialization. Graph query languages. Cypher, openCypher or GQL semantics: pattern matching, variable-length traversal and path semantics. ANTLR grammar experience is a plus. gRPC and protobuf contract design. Evolving wire contracts between services without breaking them Nice to Have API development experience Prior experience at an early-stage startup, developing systems and processes from scratch. Knowledge graphs and ontologies Experience with Data Connectors Experience with Agentic systems Why Join Us? We’re a fast-moving, well-funded startup based in San Mateo, working onsite with flexible hours because the best ideas happen when smart people collaborate in person. We take ownership of our work, move with urgency while maintaining quality, and focus on delivering real results—not just effort. We offer competitive compensation, equity, full benefits (Medical, Dental, Vision, 401k), and a workspace built for collaboration, transparency, and deep technical problem-solving. We sponsor H-1B visas and assist with immigration processes to bring the best minds together!