Solana was designed from the start around a single-chain, high-throughput architecture rather than relying on layer-2 scaling, using several techniques that work together to process transactions quickly.
Proof of History
Solana's core innovation is Proof of History, a cryptographic clock that timestamps transactions before consensus, letting validators agree on transaction order without needing to communicate back and forth as much as other networks require.
Parallel transaction execution
Solana's runtime, Sealevel, can execute non-overlapping transactions in parallel across multiple cores rather than processing everything sequentially, since the network can identify in advance which transactions do not touch the same accounts.
The tradeoff
This performance-first design has come with real reliability costs — Solana has had multiple network outages in its history under extreme load, a tradeoff discussed in more detail in the network-outages piece on this site.
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