How Does Bitcoin Record Transactions?
From signed transactions to blocks to the blockchain. How Bitcoin creates a tamper-evident record of every transfer ever made.
How Does Bitcoin Use Cryptography?
Hash functions and key pairs: the two cryptographic foundations that make Bitcoin secure. Explained without math, using examples you can verify yourself.
Why Was Bitcoin Created?
Bitcoin emerged during the 2008 financial crisis. It solved a problem that decades of research could not: how to transfer value digitally without trusting any institution.
What Is Bitcoin?
Bitcoin is both a new form of money and a new kind of monetary system. Two definitions that explain what makes it different from anything that came before.
Smart Contracts 04: Deployment
Deploy the InteractionLogger smart contract to a local Hardhat node and to Arbitrum Sepolia, verify it on Arbiscan, and interact with it via console and blockchain explorer.
Smart Contracts 03: Testing
Write a complete TypeScript test suite for the InteractionLogger smart contract using Hardhat, Ethers, Mocha, and Chai - covering happy paths, emitted events, and custom error reverts.
Smart Contracts 02: Development
Build the InteractionLogger smart contract from scratch in Solidity. Learn how to use structs, mappings, events, custom errors, and validation logic - section by section with full code and explanations.
Smart Contracts 01: Setup
Install Node.js, VS Code and MetaMask, create a test wallet, get SepoliaETH, and bridge it to Arbitrum Sepolia - everything you need before writing your first smart contract.