Build a Blockchain from Scratch
Build a working blockchain: blocks with prev-hash linking, Merkle trees with proofs, proof-of-work mining with difficulty adjustment, UTXO transactions, double-spend defense, and consensus alternatives (PoS, BFT). The data structure + cryptography behind Bitcoin, Ethereum, and every cryptocurrency.
advanced17 lessons7 chapters17 graded exercisesPython
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What you’ll have built
Chapter by chapter. Every step is a graded exercise.
- Blocks & Hashing
- Merkle Trees
- Proof of Work
- Transactions & UTXO
- Cryptography Foundations
- Scripts & Mempool
- P2P & Fork Choice
Starts in Python — solve in the language you choose in the editor, same tests either way.
Curriculum
7 chapters, 17 lessons. Each lesson is a short read, one graded exercise, and a quiz.
- 1Block StructureRead · exercise · quiz
- 2Chain ValidationRead · exercise · quiz
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