Over the past few days in #100DaysOfSolana, I went from knowing almost nothing about Solana transactions to building my own CLI transfer tool, tracking transaction confirmations in real time, and debugging failed on-chain transactions. Coming from a backend/web2 background, Solana transactions initially felt confusing. Terms like signatures, blockhashes, commitment levels, and atomic state changes sounded very different from the APIs and databases I was used to. But after building and breaking transactions myself, something finally clicked. In this post, I want to explain Solana transactions from the perspective of a backend developer. ⸻ The Mental Model Shift At first, I treated a Solana transaction like an HTTP request: `POST /transfer { "from": "...", "to": "...", "amount": 0.01 }` But that mental model is incomplete. A Solana transaction is closer to a signed, atomic database transaction that gets executed by a decentralized network.…