โ›“ Free Course

Blockchain
From Bitcoin to DApps

Start from the prehistory of digital money. Build a cryptocurrency from scratch in Node.js. Deploy Solidity smart contracts on Ethereum. Set up a private enterprise network.

21 modules
3 parts
100% free
Node.js prerequisite

Three-Part Journey

Each part builds on the previous. No shortcuts โ€” but the payoff is real.

โ‚ฟ Part 1

Bitcoin & Blockchain Foundations

Understand why Bitcoin was invented and how it works at every layer โ€” cryptography, consensus, mining, P2P networking.

The Hook โ€” a live Bitcoin transaction
Why Bitcoin? Prehistory of digital cash
Cryptographic toolkit (hashing, signatures)
Building a cryptocurrency in Node.js
Decentralisation & Proof of Work
Bitcoin network, forks & Proof of Stake
ฮž Part 2

Smart Contracts & DApps (EVM)

Write, test, and deploy production-quality Solidity contracts. Build a full-stack DApp with a Node.js frontend.

From Bitcoin Script to Ethereum EVM
Solidity fundamentals & patterns (Remix)
ERC-20 โ€” your ScroogeCoin, decentralised
Hardhat v3 + viem (TypeScript)
DApp frontend โ€” MetaMask + viem
Security, L2s & Sepolia deployment
๐Ÿข Part 3

Enterprise & Permissioned Blockchains

Apply the same Solidity skills to private networks. Understand the enterprise landscape โ€” and why it exists.

Why permissioned? Enterprise requirements
Ecosystem: Besu, Fabric, Corda, Avalanche L1s
Hyperledger Besu โ€” private network hands-on
Hyperledger Fabric โ€” conceptual deep-dive
Real-world cases, what worked, what didn't

All Modules

Start from Module 0 โ€” each module ends with a hands-on exercise in Node.js or Solidity.

โ›“ Part 1 โ€” Bitcoin & Blockchain Foundations
0

The Hook โ€” Your First Bitcoin Transaction

Read a live Bitcoin transaction on mempool.space. By the end of this course you'll understand every byte.

explorerorientation
โ†’
1

Why Bitcoin? โ€” Prehistory of Digital Cash

From Chaumian ecash to HashCash. Why every previous attempt failed and what Bitcoin did differently.

historydouble-spend
โ†’
2

Cryptographic Toolkit

Hash functions, asymmetric keys, digital signatures, Merkle trees โ€” explained practically in Node.js.

SHA-256ECDSANode.js
โ†’
3

Building a Cryptocurrency in Node.js

Implement GoofyCoin โ†’ ScroogeCoin โ†’ decentralise it. Hands-on with Node.js crypto module.

Node.jsUTXOhands-on
โ†’
4

Decentralisation & Proof of Work

P2P networks, gossip protocol, Nakamoto consensus, forks, 51% attack. Build a P2P node simulation.

P2PPoWconsensus
โ†’
5

Bitcoin Network, Forks & Proof of Stake

Gossip protocol, SPV nodes, BIPs, hard/soft forks. The Ethereum Merge explained.

P2PPoSforks
๐Ÿ”’
ฮž Part 2 โ€” Smart Contracts & DApps (EVM)
6

From Bitcoin Script to Ethereum EVM

Why Bitcoin's scripting language isn't enough. EVM, gas, accounts (EOA vs contract), Wei/Gwei/ETH.

EVMgasaccounts
๐Ÿ”’
7

Solidity Fundamentals โ€” Remix IDE

Types, functions, visibility, events, modifiers. Build and deploy a Counter contract in Remix.

Solidity 0.8Remixhands-on
๐Ÿ”’
8

Solidity Patterns

Mappings, structs, inheritance, custom errors. Build a Voting contract from scratch.

mappingsstructsOZ v5
๐Ÿ”’
9

ERC-20 โ€” ScroogeCoin, Finally Decentralised

Token standards, OpenZeppelin v5, deploy your own ERC-20 on Remix then Sepolia.

ERC-20OpenZeppelinSepolia
๐Ÿ”’
10

Professional Tooling โ€” Hardhat v3

Move from Remix to a real project: Hardhat v3, Ignition, TypeScript config, local devnet.

Hardhat v3TypeScriptnpm
๐Ÿ”’
11

Testing Smart Contracts

TypeScript tests with viem. describe/it patterns you already know. Test the ERC-20.

viemtestingTypeScript
๐Ÿ”’
12

DApp Frontend โ€” MetaMask + viem

Connect a wallet, read state, write transactions, listen to events. Pure HTML/JS โ€” no framework needed.

viemMetaMaskfrontend
๐Ÿ”’
13

Smart Contract Security

Reentrancy (The DAO hack), tx.origin, overflow, oracle manipulation. Run Slither on your code.

securitySlitherauditing
๐Ÿ”’
14

Deployment & Scalability

Hardhat Ignition, Etherscan verification, Layer 2 landscape (Arbitrum, Base, zkSync, Starknet).

IgnitionL2rollups
๐Ÿ”’
๐Ÿข Part 3 โ€” Enterprise & Permissioned Blockchains
15

Why Permissioned? Enterprise Requirements

Privacy, compliance, finality, identity. The decentralisation trilemma revisited for enterprises.

permissionedGDPRfinality
๐Ÿ”’
16

Enterprise Ecosystem Landscape

Hyperledger Besu, Fabric, R3 Corda, Avalanche L1s. Positioning matrix: choose the right tool.

BesuFabricCorda
๐Ÿ”’
17

Hyperledger Besu โ€” Private Network Hands-on

Spin up a 4-node QBFT network with Docker Compose. Deploy the ERC-20 from Part 2. Same code, different network.

BesuQBFTDocker
๐Ÿ”’
18

Hyperledger Fabric โ€” Conceptual Deep-Dive

Peers, orderers, channels, MSP, chaincode. Endorsement policies. When Fabric beats Besu.

Fabricchaincodechannels
๐Ÿ”’
19

Real-world Cases & What's Next

TradeLens autopsy, CBDC pilots, ZK proofs, ERC-4337, AI agents owning wallets. Career paths.

ZKERC-4337careers
๐Ÿ”’

Tools You'll Use

All free, all current, all used in the industry in 2026.

๐Ÿ”ง
Remix IDE
Browser-based Solidity IDE. Zero setup.
Part 2
โš’๏ธ
Hardhat v3
Node.js dev environment. Rust-powered runtime.
Part 2
๐ŸŒŠ
viem
TypeScript-first Ethereum library.
Part 2
๐ŸฆŠ
MetaMask
Browser wallet for testing DApps.
Part 2
๐Ÿงช
Sepolia Testnet
Free ETH, full EVM โ€” the active testnet.
Part 2
๐Ÿ›ก๏ธ
OpenZeppelin v5
Audited contract library. ERC standards.
Part 2
๐Ÿ”ฌ
Slither
Static analysis tool for Solidity security.
Part 2
๐Ÿณ
Hyperledger Besu
EVM-compatible enterprise client (Java).
Part 3
๐Ÿ”
mempool.space
Live Bitcoin block explorer used from Day 1.
Part 1

Ready to break open the black box?

Module 0 takes 30 minutes. You'll read a real Bitcoin transaction live.

Start with Module 0