Senior Software Engineer, Database (SmithDB)

SmithDB is LangChain's internal database team. We're building a storage and query layer purpose-built for AI observability and evaluation. Within six months we went from idea to a production system that offers industry leading performance and scalability for agent observability data. We're a small, fast team of systems engineers tackling genuinely hard problems: storage layout, query execution, compaction, and scaling toward trillions of agent traces. We develop in Rust, run on Kubernetes, and integrate tightly with S3/GCS/Azure Blob. There are no legacy constraints; this is a greenfield system with real production load and ambitious engineering goals.

We're a fast-moving team looking for a systems / database engineer to help design, optimize, and harden our system. Within 6 months, we've gone from idea to production system but there is still lots to build and optimize. You'll be working on execution, storage layout, performance profiling, and scaling to trillions of traces. This role is based in San Francisco.

- Engineer performant Rust code for ingestion and query execution

- Optimize for cost and speed, heavily utilizing memory and CPU profiling

- Integrate tightly with cloud object stores (S3/GCS/Azure Blob)

- Deploy our distributed database services on Kubernetes (multi-tenant, high throughput, low latency)

- Contribute to observability for the storage engine itself (metrics, tracing, debug tooling)

- 5+ years in systems/database engineering with strong experience in a systems programming language (Rust, C++). Rust strongly preferred, as it is the language we use.

- Knowledge of database internals is a plus: query engines, storage systems, indexing, and compaction

- Proficiency in systems performance analysis: memory allocation, CPU hotspots, lock contention, async runtimes.

- Familiarity with similar query execution engines is a plus

- Experience with Kubernetes, distributed systems, and cloud object storage is a plus.