Indeed, a major online job platform, manages over 25 million job listings and 225 million resumes with 250 million unique users monthly, relying heavily on MongoDB for about 50% of its operations. At MongoDB World 2022, Alex Leong, a senior cloud database engineer at Indeed, discussed challenges in managing replica sets across multiple data centers, such as performance issues, replication lags, and changes in sync sources. Leong emphasized the importance of quick initial node synchronization to avoid stale data and highlighted the need to monitor and adjust sync sources proactively to maintain write performance. Additionally, the session covered the complexities of cross-data center configurations, including the necessity of configuring write concerns carefully to handle failovers and the use of WiredTiger cache sizing to enhance replication speed.