Ehsan Nasr worked on enhancing Firestore’s offline-first reliability by improving integration testing in both the firebase/firebase-android-sdk and firebase/firebase-js-sdk repositories. He expanded Android test coverage by pre-populating caches, performing full-cache scans, and validating data consistency across online and offline queries, using Java and TypeScript. Ehsan refactored the checkOnlineAndOfflineResultsMatch utility to ensure identical results from all query methods, reducing the risk of data divergence. On the JavaScript SDK, he added missing test cases and improved test helpers to maintain parity between online and offline data retrieval, resulting in earlier detection of edge-case regressions and more robust release cycles.