Code
Blockchain Fundamentals — example repository
The minimal chain built across the series: block structure, hash linking, validation and a toy consensus loop, in one runnable project.
- TypeScript
- #blockchain
- #hashing
- #consensus
Series
Blockchain Fundamentals
Start with the fundamentals and understand how blockchain systems actually work — from the problem they were built to solve through to the consensus that keeps them honest.
- Blockchain
- 4 episodes
Most blockchain explanations start in the wrong place. They open with a definition, move quickly to a diagram of linked boxes, and arrive at "and that's why it's immutable" without ever saying what problem the design was answering.
This series works in the opposite direction. Each episode starts from something that does not work, then shows the mechanism that was invented to deal with it. By the end you should be able to read a chain's documentation and understand what its designers were trading away, which is the skill that transfers to every system you meet afterwards.
There is no prerequisite beyond being comfortable with the idea of a database and a network. No cryptography background is assumed; the parts you need are built up as they become necessary.
Study materials
What goes with this series
- References
Bitcoin: A Peer-to-Peer Electronic Cash System (opens in a new tab)
The original 2008 paper. Nine pages, and still the clearest statement of the double-spending problem and the proof-of-work answer to it.
- #primary-source
- #consensus
Open resource
- References
Ethereum developer documentation (opens in a new tab)
Reference for accounts, transactions, gas, the EVM and the node software. The section on transaction lifecycle pairs directly with episode three.
- #evm
- #transactions
Open resource
- Notes
Blockchain Fundamentals — study notes
Condensed notes for the series: the vocabulary, the four conditions, the consensus comparison table and the questions to ask of any chain.
- #reference
- #summary
- Examples
Consensus mechanisms — runnable comparison
Small standalone programs that run a proof-of-work loop and a BFT voting round side by side, so the difference in message count and finality is visible rather than described.
- TypeScript
- #consensus
- #simulation
Related
Read alongside
- Article
Blockchain
Where Blockchain Does Not Make Sense
Five proposals that come up repeatedly, why each one fails on inspection, and what the person asking for it usually actually needs.
Read
- Article
Blockchain
Why Blockchain Exists
Blockchain was not invented to be a database. It was invented to answer one question about digital money that had gone unanswered for twenty years.
Read