Here is a 200-250 word comparison of the two open-source projects for senior engineers: A comparison of GreptimeTeam/greptimedb and risingwavelabs/risingwave reveals distinct profiles in terms of momentum, community size, and use cases. Greptimedb, with 6,115 stars and a recent surge of 61 stars over the last 30 days, indicates a growing but somewhat niche interest. In contrast, risingwave boasts 9,084 stars, with a more substantial 90 stars added in the same period, suggesting broader appeal and faster momentum. The community size, inferred from star counts, is larger for risingwave, potentially implying more contributors, users, and thus, possibly, more extensive support and feedback loops. Greptimedb's community, while smaller, is still notable and actively growing. Use cases diverge significantly: Greptimedb is positioned as a unified backend for metrics, logs, and traces, aiming to replace Prometheus, Loki, and Elasticsearch with the added benefit of SQL and PromQL on object storage. This makes it appealing for teams seeking to consolidate their observability stack. Risingwave, on the other hand, is tailored for real-time stream processing, low-latency serving, and Iceberg table management, catering to needs in streaming data processing and real-time analytics. Senior engineers should choose based on whether their primary challenge lies in unified observability (Greptimedb) or streaming data management (Risingwave).