Designing Data-Intensive Applications: The Big Ideas Behind Reliable, Scalable, and Maintainable Systems

by Martin Kleppmann

By contrast, event-based systems can provide better auditability. In the event sourcing approach, user input to the system is represented as a single immutable event, and any resulting state updates are derived from that event.

am somewhat skeptical about the Byzantine fault tolerance aspects of these technologies (see “Byzantine Faults”), and I find the technique of proof of work (e.g., Bitcoin mining) extraordinarily wasteful. The transaction throughput of Bitcoin is rather low, albeit for political and economic reasons more than for technical ones. However, the integrity checking aspects are interesting.

Cryptographic auditing and integrity checking often relies on Merkle trees [74],

For a user who does not consent to surveillance, the only real alternative is simply not to use a service. But this choice is not free either: if a service is so popular that it is “regarded by most people as essential for basic social participation”