WalmartLabs

We're a small close-knit team backed by big company resources. We write mission-critical, robust software that's used by millions of Walmart's customers daily. Our suite of software includes but is certainly not limited to: a large distributed system that processes all store transactions from every Walmart and Sam's Club store in the US. If you've ever used Walmart Pay, this is how you get your receipt! A massive GraphQL service that powers all customer purchase & returns history for all platforms (written using our own open-source GraphQL implementation for Clojure). We roll out new marquee customer-facing features in this service almost weekly: everything from tire installation services to bakery orders to propane tanks. Services to allow customers to manage and purchase care plans, push notifications. Our tech stack is: Clojure (for everything!), GraphQL, Cassandra, Kafka, Redis, Prometheus, Ruby (for some infrastructure tasks).