  Sui Lutris is the first smart-contract platform to sustainably achieve
sub-second finality. It achieves this significant decrease by employing
consensusless agreement not only for simple payments but for a large variety of
transactions. Unlike prior work, Sui Lutris neither compromises expressiveness
nor throughput and can run perpetually without restarts. Sui Lutris achieves
this by safely integrating consensuless agreement with a high-throughput
consensus protocol that is invoked out of the critical finality path but
ensures that when a transaction is at risk of inconsistent concurrent accesses,
its settlement is delayed until the total ordering is resolved. Building such a
hybrid architecture is especially delicate during reconfiguration events, where
the system needs to preserve the safety of the consensusless path without
compromising the long-term liveness of potentially misconfigured clients. We
thus develop a novel reconfiguration protocol, the first to provably show the
safe and efficient reconfiguration of a consensusless blockchain. Sui Lutris is
currently running in production and underpins the Sui smart-contract platform.
Combined with the use of Objects instead of accounts it enables the safe
execution of smart contracts that expose objects as a first-class resource. In
our experiments Sui Lutris achieves latency lower than 0.5 seconds for
throughput up to 5,000 certificates per second (150k ops/s with transaction
blocks), compared to the state-of-the-art real-world consensus latencies of 3
seconds. Furthermore, it gracefully handles validators crash-recovery and does
not suffer visible performance degradation during reconfiguration.
