Writing on-chain logic as a Rust program
On Solana, the smart contract equivalent is called a program, and it's written in Rust and compiled ahead of time, rather than being interpreted line by line the way some other chains handle contract code. A Solana program's core job is to read and write account data according to the logic the developer wrote, and because Solana's architecture separates code from the state it operates on, the same program logic can be reused across many different accounts rather than each deployment bundling its own storage. This course assumes you've already seen Solana's account model and execution architecture in a general Solana course. Here the focus is narrower: what it actually feels like to build the program logic itself, and why Rust specifically is the language for that job.
Writing raw Solana programs directly involves a fair amount of repetitive, error-prone boilerplate: manually checking account ownership, manually verifying account data layouts, manually handling serialization of data going in and out of accounts. Getting any of that wrong is exactly the kind of mistake that can open a security hole, which is a serious concern in an ecosystem where deployed programs often hold real value.