You now understand the core concepts of distributed systems.
Latency is time per request. Throughput is requests per second. Optimizing one can hurt the other.
Availability is measured in nines. % means hours of downtime per year.
Scale vertically (bigger machines) or horizontally (more machines). Large systems scale horizontally.
CAP theorem: choose consistency or availability during network partitions.
Most systems use eventual consistency. Strong consistency is expensive.
Eliminate single points of failure through redundancy.