Sebastian Rodriguez focused on backend reliability in the cashapp/misk repository, addressing correctness in the in-memory Redis emulation layer. He delivered a targeted bug fix for the DEL operation in FakeRedis, ensuring that key removal worked consistently across strings, hashes, lists, and sorted sets. Using Kotlin and leveraging his experience with Redis and testing, Sebastian implemented comprehensive tests to validate deletion behavior for various data types, aligning FakeRedis semantics with actual Redis expectations. This work improved the accuracy of caching and integration test suites, reducing risk for downstream services that depend on consistent DEL behavior in their development and testing environments.