In January 2025, Alessandro Lacchini focused on backend reliability for the istio/istio repository, addressing a race condition in the JWKS resolver cache. He implemented a concurrency-safe compare-and-swap mechanism in Go, ensuring atomic updates to the cache during JWT public key retrieval. This approach mitigated TOCTOU issues, reducing intermittent validation failures and enhancing authentication stability under high load and key rollover scenarios. Alessandro applied advanced concurrency handling and testing techniques to strengthen the resilience and security of Istio’s authentication component. His work demonstrated depth in backend engineering, particularly in designing robust, thread-safe systems for high-traffic distributed environments.