As a developer tools analyst, I've compared Apache Kylin (Project A) and RisingWave (Project B) based on momentum, community size, and apparent use cases, tailored for senior engineers. **Momentum and Community Size**: RisingWave (Project B) exhibits significantly higher momentum, with 9,084 stars overall and a notable 90 stars gained in the last 30 days, indicating rapid growth and current interest. In contrast, Apache Kylin (Project A) has 3,776 stars, with a modest gain of 3 stars over the same period, suggesting a more mature but less dynamically growing project at present. **Apparent Use Cases**: Apache Kylin is designed for big data analytics, particularly suited for ad-hoc queries on large datasets, leveraging its columnar storage and in-memory computing capabilities. It's ideal for batch processing and historical data analysis, commonly used in business intelligence and data warehousing scenarios. RisingWave, on the other hand, is positioned as a streaming data platform, emphasizing real-time stream processing, low-latency serving, and Iceberg table management. This positions it for applications requiring immediate data insights, such as live analytics, IoT data processing, and real-time decision-making systems. **Comparison Summary for Senior Engineers**: - **Choose Apache Kylin for**: Mature, batch-oriented big data analytics with established community practices. - **Choose RisingWave for**: Emerging, high-growth projects needing real-time data capabilities, despite its less mature but rapidly expanding community.