Interesting seeing the death of blockchain-based AWS QLDB mentioned. I worked at a company for a while that used QLDB as the primary system of record. The ide

Interesting seeing the death of blockchain-based AWS QLDB mentioned. I worked at a company for a while that used QLDB as the primary system of record. The idea is great but the problem is that due to performance and other QLDB limitations all data had to be mirrored to an RDBMS via a streaming/queuing system, and there always were programmatic errors in interpreting data arriving for import into the RDBMS ... text field too long for RDBMS field; wrong data type or overflowing integer; invalid text encoding; ... Etc. These errors had to be noticed, debugged, fixed, and data had to be re-streamed. In the meantime official transactions were missing from the RDBMS side, which was used for reporting, driving the UI, deriving monetary obligations, etc. it was not worth the trouble. (I was lucky to not be involved in that design or implementation.)