Airbnb has rearchitected its key-value store, Mussel, transitioning from v1 to v2 to meet new demands for real-time data handling and scalability. The new architecture addresses challenges such as operational complexity, consistency flexibility, and data governance, while ensuring a smooth migration process with zero data loss. Key features of v2 include dynamic sharding, automated data expiration, and a robust migration pipeline utilizing Kafka for consistency.

A software team faced a critical issue with a primary key limit on their calendar application, which was approaching the maximum value for a signed 32-bit integer. To avoid breaking customer integrations, they implemented a temporary hack by setting the sequence to utilize the negative range of integers, buying them time to transition to a more robust solution while managing technical debt responsibly. Ultimately, the quick decision allowed for a smooth transition and effective communication with customers.

Motion transitioned from CockroachDB to Postgres due to escalating costs and operational challenges, particularly with migrations and ETL processes. The migration revealed better performance with Postgres for many queries, despite some initial advantages of Cockroach’s query planner. The move ultimately streamlined operations and resolved numerous UI and support issues experienced with CockroachDB.