Tons of round trip calls potentially in most RPC-style systems are one start, which Cap'n Proto addresses with its unique style of avoiding round-trips for many

Tons of round trip calls potentially in most RPC-style systems are one start, which Cap'n Proto addresses with its unique style of avoiding round-trips for many network transactions which can drastically reduce network chatter. Security is addressed simultaneously (but not necessarily sufficiently for many people or regulatory bodies) in Cap'n Proto at least via use of capabilities instead of building it into transport layers.