Build What You Can't Fake

Blockchain Development is a free learning path on Breni. It runs to 14 courses and takes about 8 weeks. It starts at intermediate level. You finish able to understand how blockchains actually work — the mental model behind every crypto and web3 headline you see.

  • 14 courses
  • 211 learning objectives
  • 8 weeks estimated
  • Level: intermediate
  • Language: English
  • Price: Free

What you will be able to do

  • Understand how blockchains actually work — the mental model behind every crypto and web3 headline you see
  • Set up a wallet and send real transactions on a live blockchain with confidence, not confusion
  • Write, test, and deploy real smart contracts in Solidity — not just read about them
  • Build and launch your own token and NFT collection from scratch
  • Ship a working dApp end-to-end and understand where real blockchain careers actually are

Full curriculum

1. Demystifying the Block: The Under-the-Hood Mechanics of Trustless Networks

I keep hearing about blockchain and crypto but I don't actually understand what's happening under the hood

  • Novice — The Ledger Detective
    Deconstructs the foundational elements of a digital ledger and demystifies how cryptographic hashing establishes a permanent, tamper-resistant record.
    • What's in a Block?
    • The Magic of Hashing
    • Ledger vs. Database
  • Learner — The Chain Linker
    Examines how individual blocks are securely connected over time and maps out the chronological structure that locks history in place.
    • The Chain Reaction
    • The Genesis Block
    • Tamper Detection Simulation
  • Skilled — The Consensus Architect
    Navigates how thousands of independent computers agree on a single database state without a boss, resolving the elusive double-spend problem.
    • The Double-Spend Problem
    • Proof of Work & Mining
    • Distributed P2P Networks
  • Advanced — The Fork Navigator
    Explains how the network handles latency, resolves competing block claims, and achieves fault tolerance during real-time transaction splits.
    • The Longest Chain Rule
    • Proof of Stake & Beyond
    • Byzantine Fault Tolerance
  • Expert / Maestro — The Trustless Cryptographer
    Master the cryptographic identity layer and state-management paradigms that convert a secure database into an active global computer.
    • Asymmetric Cryptography
    • UTXO vs Account Models
    • Smart Contract Mechanics

2. Unbreakable Chains: The Mechanics of Immutability

I want to understand what actually makes a blockchain 'unchangeable'

  • Novice — The Digital Fingerprint
    Understand how a cryptographic hash functions as an unforgeable, one-way digital fingerprint for any piece of data.
    • Deterministic Outputs & The Avalanche Effect
    • The One-Way Cryptographic Street
    • Hands-on Hashing Lab
  • Learner — The Block Blueprint
    Learn the anatomical structure of a single block and how transaction data is packaged securely.
    • Anatomy of a Block
    • Packaging Transactions
    • Block Reconstruction Lab
  • Skilled — The Cryptographic Link
    Grasp how linking blocks sequentially using previous hashes forms an unbreakable chain.
    • The Previous Hash Pointer
    • The Genesis Anchor
    • Chain Assembly Lab
  • Advanced — The Tamper-Proof Test
    Analyze what happens when a bad actor tries to rewrite history and why the chain resists it.
    • The Chain Reaction
    • The Computational Barrier
    • Tamper Auditing Lab
  • Expert / Maestro — Network Consensus
    Explore how a distributed peer-to-peer network rejects rogue ledgers to enforce truth.
    • The Shared Truth
    • Rejecting the Rogue
    • Consensus Simulation Lab

3. Owning Your Coins: Keys, Wallets, and the Reality of Trustless Control

I want to actually understand what a wallet is and why losing my keys means losing everything

  • Novice — The Digital Locksmith
    Dispel the myth of 'holding' physical coins. Understand that your wallet is a keychain, and the blockchain is the real vault where ownership is recorded.
    • The Location Illusion
    • Public vs. Private Keys
    • The Point of No Return
  • Learner — The Secret Signer
    Learn how asymmetric cryptography authorizes ownership. Discover how private keys generate cryptographic signatures to spend funds without ever revealing the keys.
    • One-Way Mathematics
    • The Magic of Signing
    • Nodes as Verification Judges
  • Skilled — The Master Key Generator
    Bridge the gap between ugly alphanumeric keys and human-friendly seed phrases. Discover BIP-39 and how Hierarchical Deterministic (HD) wallets organize your assets.
    • From Words to Keys (BIP-39)
    • The Infinite Keychain (BIP-32/44)
    • Entropy and Uniqueness
  • Advanced — The Custody Strategist
    Navigate the security spectrum. Analyze the tradeoffs between cold storage, hot wallets, and centralized exchanges to formulate your own safe storage strategy.
    • Hot vs. Cold Storage
    • Not Your Keys, Not Your Coins
    • Secure Backups & Passphrases
  • Expert / Maestro — The Cryptographic Guardian
    Master multi-party security and advanced recovery protocols. Learn how multi-signature accounts and account abstraction secure assets beyond single points of failure.
    • Multi-Signature Security
    • Social Recovery & Smart Wallets
    • The Ultimate Legacy Plan

4. Your First Transaction: Sending Value On-Chain

I want to actually send a transaction and understand every part of what just happened

  • Novice — Anatomist of the Ledger
    You understand the anatomy of a transaction payload, distinguishing target addresses from dynamic, gas-adjusting parameters that keep transactions safe from replay attacks.
    • The Anatomy of Intent
    • The Guardrails of State
    • Crafting the Unsigned Payload
  • Learner — Gas Auctioneer
    You master the economics of Ethereum's dynamic fee market, understanding how base fees are burned and priority fees incentivize validators.
    • EIP-1559 Fee Dynamics
    • Calculated Inevitability
    • The Dynamic Fee Estimator
  • Skilled — Cryptographic Blacksmith
    You bridge the gap between human intention and raw machine bytecode by serializing, hashing, and cryptographically signing transaction payloads.
    • RLP Serialization
    • Secp256k1 Signature Synthesis
    • The Raw Byte Forge
  • Advanced — Mempool Navigator
    You control the transaction lifecycle from local broadcast through the gossip protocol, local pool queues, validation, and block execution.
    • JSON-RPC and the Gateway
    • Mempool Priority Queuing
    • The Broadcast Pipeline
  • Expert / Maestro — Mempool Master & Rescue Agent
    You handle complex state collisions, rescue stuck transactions via gas replacement, and diagnose failed/reverted executions on-chain.
    • Sequential Ordering & Nonce Collisions
    • Transaction Replacement & Cancellation
    • Post-Mortem Execution Analysis

5. Beyond the Balance: What a Smart Contract Actually Is

Everyone says 'smart contract' like I should know what that means — I don't

  • Novice — The Code Account
    Shift your perspective from user-controlled wallets to automated, code-driven accounts that live on-chain and respond deterministically to transactions.
    • The Self-Executing Account
    • The Vending Machine Blueprint
    • Unpacking the Code Address
  • Learner — Anatomy of State and Logic
    Explore how smart contracts hold global persistent data on a decentralized ledger and expose public execution paths.
    • State vs. Memory
    • Reading vs. Writing State
    • Designing Contract Functions
  • Skilled — Guards and Reverts
    Learn how contracts enforce business rules autonomously, stopping invalid interactions and preventing partial updates.
    • Enforcing Rules with Require
    • The Magic of Atomic Reverts
    • Handling Errors and Gas
  • Advanced — Decentralized Compilation
    Understand how high-level human-readable code translates into bytecode executed by nodes across a global network.
    • From Solidity to Bytecode
    • The EVM Engine
    • Decoding Transaction Receipts
  • Expert / Maestro — Autonomous Trust and Deployment
    Master the deployment of unalterable logic and understand how contracts live permanently on a public ledger.
    • The Immutability Trade-off
    • The Global Lifecycle of a Contract
    • Launching an Autonomous Actor

6. Deconstructing Code: Line-by-Line to Your First Smart Contract

I want to actually write and understand a real smart contract, line by line

  • Novice — Blueprint Reader
    Can identify the basic anatomy of a Solidity contract file, including the license, pragma directive, and contract wrapper.
    • License & Version Pragma Check
    • The Contract Shell
    • Anatomy of a Basic Contract
  • Learner — State Setter
    Understands how to store persistent data on-chain using basic state variables and configure visibility.
    • Understanding Value Types
    • State vs. Local Variables
    • Unveiling Visibility Specifiers
  • Skilled — Function Architect
    Writes standard state-modifying functions and understands how they execute transactions.
    • Declaring Modifying Functions
    • Function Parameters
    • Gas Costs of Writing State
  • Advanced — State Reader
    Implements non-state-modifying functions to retrieve contract data without incurring gas costs.
    • The 'view' Keyword
    • The 'pure' Keyword
    • Read vs. Write Execution
  • Expert / Maestro — Contract Deployer
    Constructs, instantiates, and initializes a complete custom contract containing persistent records.
    • Working with Constructors
    • Line-by-Line Synthesis
    • Deploying and Testing Basics

7. On-Chain Launchpad: Deploying Contracts to Live Testnets

I've written code before but never actually deployed something onto a blockchain — I want to do that

  • Novice — Local Sandbox Pioneer
    Learn the fundamentals of compiling contract code, understanding deployment payloads, and simulating deployments on an in-memory local blockchain.
    • Decoding the Bytecode and ABI
    • Spinning Up Local Nodes
    • Deploying Your First Sandbox Contract
  • Learner — Testnet Pioneer
    Transition from localhost to public testnets. Set up wallets, configure providers, and acquire testnet ETH.
    • Setting Up Wallet and Testnet RPCs
    • Funding Your Testnet Wallet
    • Querying Public Blockchain State
    • Demystifying Network Gas Fees
  • Skilled — Scripting Sorcerer
    Abandon manual browser deployment methods for scalable command-line scripts and secure secret management.
    • Securing Private Keys with Environment Variables
    • Executing Programmatic Deployments
    • Decoding Transaction Receipts
  • Advanced — Explorer Scout
    Verify your contract source code on block explorers and interact with live state functions.
    • Preparing Code for Explorer Verification
    • Programmatic Contract Verification
    • Interacting via Verified Block Explorers
  • Expert / Maestro — Deployment Architect
    Master production-grade deployment techniques, determinism, and automated pipelines.
    • Architecting Deterministic Deployments
    • Automating Deployments with CI/CD
    • Optimizing Deployment Gas Footprints

8. Access Control & Payable Functions: Handling Real Money Safely

I want my contract to actually hold and move funds, and I want to do it without getting exploited

  • Novice — The Payable Gateway
    Master the fundamentals of accepting native cryptocurrency and validating incoming transaction values securely.
    • Unlocking the Payable Modifier
    • Reading Transaction Values
    • The Secure Portal Lab
  • Learner — The Vault Keeper
    Implement state-based accounting to track individual user funds and establish ownership-based administrative boundaries.
    • Mapping User Ledger Balances
    • Owner-Based Protections
    • The PiggyBank Lab
  • Skilled — The Outflow Architect
    Master secure outbound transfer methods and capture direct incoming Ether without using named functions.
    • Deciphering Outbound Methods
    • Unstructured Ether Interception
    • The Fund Dispatcher Lab
  • Advanced — The Shielded Ledger
    Protect the ledger from reentrancy exploits and eliminate denial-of-service vectors using the Pull-over-Push design pattern.
    • The Pull-over-Push Architecture
    • Checks-Effects-Interactions Pattern
    • The Secure Payout Lab
  • Expert / Maestro — The Multi-Role Citadel
    Integrate industry-standard security frameworks to govern administrative access and secure critical financial pathways.
    • Standardizing Ownership Guardrails
    • Role-Based Authority Matrix
    • The SecureVault Citadel Lab

9. Security Basics: The Mistakes That Cost Millions

I keep hearing about hacks and exploits — I want to know what actually goes wrong so I don't repeat it

  • Novice — The Reentrancy Guard
    Master state-tracking hygiene and the Checks-Effects-Interactions pattern to neutralize the most infamous vulnerability in Ethereum history.
    • Deconstruct Reentrancy Mechanics
    • Implement Checks-Effects-Interactions (CEI)
    • Deploy Guard Modifiers
  • Learner — Precision & Phishing Patrol
    Avoid basic execution flaws including integer truncation in division calculations and unsafe user authentication practices.
    • Correct Truncation and Precision Errors
    • Manage Downcasting Risks
    • Differentiate tx.origin vs msg.sender
  • Skilled — The Logic Gatekeeper
    Secure critical initialization steps in contract logic and prevent state-cleaning bugs that break execution flow.
    • Secure Proxy Initializers
    • Protect Uninitialized State Pointers
    • Audit Array Deletion Anomalies
  • Advanced — The Oracle Shield
    Defend decentralized valuations against flash-loan attacks by swapping volatile spot prices for reliable, manipulated-resistant oracles.
    • Mitigate Spot Price Manipulation
    • Implement Time-Weighted Average Prices (TWAP)
    • Assess Raw Balance Insecurities
  • Expert / Maestro — Cryptographic Crypt-Keeper
    Deconstruct advanced cryptography issues by neutralizing signature-replay schemes and managing transaction ordering slip-ups.
    • Prevent Signature Replay Attacks
    • Audit ERC-20 Approve Race Conditions
    • Apply Slippage Tolerance Boundaries

10. From Empty Compiler to Custom Coin: Build Your Own ERC-20

I want to actually create a token, not just read about how they work

  • Novice — Architect of the Interface
    Deconstruct the EIP-20 standard interface and map out the raw structural layout that lets web3 wallets and exchanges interact with your coin.
    • The ERC-20 Blueprint
    • Real-Time Event Mapping
    • Interface Blueprint Validator
  • Learner — The Mint Master
    Build the core state structures and raw transfer logic, establishing your token's internal balance ledger and custom minting operations.
    • The Balance Ledger Mapping
    • Safe Transfers Under the Hood
    • Creating Supply From Thin Air
  • Skilled — Allowance Administrator
    Establish standard approval pathways and execute delegated transfers, enabling third-party smart contracts to safely move funds with permission.
    • Mapping Spender Permissions
    • The Approval Shield
    • Executing Delegated Transfers
  • Advanced — Production-Grade Pioneer
    Transition your custom logic to a secure framework using OpenZeppelin, configuring custom administrative rights and modern utility behaviors.
    • Importing OpenZeppelin Core
    • Securing Minting Powers
    • Deflation and Pause Mechanisms
  • Expert / Maestro — Foundry Flight Commander
    Configure advanced local workspaces, run high-performance unit tests in Solidity, and command deployments to live testnets.
    • Foundry Workspace Architect
    • Asserting Token Behavior
    • Testnet Deployment Mechanics

11. Crafting Immutable Collections: The Hands-On ERC-721 Engineering Guide

I want to understand and build an NFT collection myself, not just buy one

  • Novice — The Provenance Pioneer
    Transition from standard fungible tokens to unique asset identifiers. Understand the foundational anatomy of the ERC-721 standard, token tracking, and minting mechanics.
    • Deciphering Uniqueness
    • The Minting Genesis
    • Metadata & Off-Chain Assets
  • Learner — The Metadata Architect
    Master the off-chain storage architecture of NFTs. Learn to package assets, compile standards-compliant JSON metadata, and distribute them using decentralized networks.
    • Drafting the Token URI
    • IPFS Addressing & Content IDs
    • Dynamic Metadata Resolution
  • Skilled — The Launch Director
    Bridge the smart contract with public users. Build collection launching mechanics, including minting caps, whitelist access lists, public sales, and pricing strategies.
    • Public Minting Mechanics
    • Access Lists with Merkle Trees
    • The Reveal Mechanic
  • Advanced — The Gas Optimizer
    Dive into technical and economic efficiency on-chain. Implement gas-saving standards like ERC721A to enable batch mints for a fraction of traditional transaction costs.
    • Anatomy of ERC721A
    • Optimizing Batch Mints
    • Packed Storage Variables
  • Expert / Maestro — The Sovereign Auditor
    Audit and secure your collection against mainnet exploits. Mitigate advanced reentrancy vectors, enforce standard-compliant royalty registries, and verify immutability.
    • Reentrancy Protection in Safe Transfers
    • EIP-2981 Royalty Integration
    • Provable Randomness via Oracles

12. The Bridge: Connecting Frontends to Smart Contracts

I have a working contract but no way for a normal person to use it — I want to fix that

  • Novice — Establishing the Portal
    Establish a basic data bridge to read blockchain state, query simple variable values, and interpret contract ABIs within your React application.
    • Wagmi Configuration Protocol
    • The ABI Translation Map
    • Reading the Ledger
  • Learner — Handshaking with Wallets
    Integrate secure wallet authentication, handle EIP-6963 multi-wallet discovery, and manage connected session states in user interfaces.
    • Multi-Wallet Discovery
    • Stateful Session Management
    • Dynamic Interface Handshaking
  • Skilled — Executing Transactions
    Construct reactive flows for sending state-mutating transactions, gathering user signatures, and tracking block-mining processes.
    • State Mutating Transactions
    • Mining and Confirmation Cycles
    • The Minting Pipe
  • Advanced — Real-Time Synchronization
    Keep your web interface fully updated by subscribing to smart contract events and invalidating frontend caches dynamically.
    • On-Chain Event Hooks
    • Automated Cache Invalidation
    • Real-Time Transaction Feeds
  • Expert / Maestro — Defensive UX & Security
    Deploy strict TypeScript typings, secure multi-network safeguards, and defensive checks to prevent invalid transactions.
    • Active Network Detection
    • TypeScript ABI Compilation
    • Multi-Network Guardrails

13. From Localhost to Mainnet: Launching Your Capstone dApp

I want to put everything together and actually launch something I built

  • Novice — Blueprint Architect
    You can successfully structure a unified, professional dApp codebase and establish clear state synchronization boundaries between your ERC-20 contract and Next.js frontend.
    • Monorepo Setup & Dependency Alignment
    • dApp State Mapping
    • Local Dev Sandbox Configuration
  • Learner — Integration Testmaster
    You can write robust integration tests that mimic real-world network latency, contract interactions, and failure scenarios.
    • Simulating Mainnet Forking
    • Asynchronous Front-End Testing
    • Event Listener Syncing
  • Skilled — UX Optimizer
    You can design and build a polished interface that handles multi-wallet connections and optimizes gas usage during high-traffic transactions.
    • Universal Wallet Integration
    • Gas Estimations & UX Guardrails
    • Transaction Receipt Recovery
  • Advanced — Testnet Deployer
    You can securely deploy your smart contracts to a public testnet, verify your code on-chain, and deploy a decentralized frontend.
    • Securing Private Deployment Keys
    • On-Chain Verification
    • Decentralized Hosting Deployment
  • Expert / Maestro — Production-Grade Shipper
    You can confidently release your dApp to Ethereum mainnet with robust security configurations, emergency controls, and monitoring systems.
    • Multi-Signature Guarding
    • Emergency Circuit Breakers
    • On-Chain Monitoring & Alerts

14. Architecting a Web3 Career: Beyond the Hype

I want to know what real jobs and paths exist in this space, not just hype

  • Novice — The Demystifier
    Strip away speculative marketing hype to identify the stable, technical, and architectural roles driving the multi-billion-dollar blockchain ecosystem.
    • Map the Tier List of Technical Roles
    • Differentiate Innovators from Derivatives
    • Design a Sustainable Career Roadmap
  • Learner — The Audit Trainee
    Immerse yourself in smart contract security auditing, one of the most resilient, elite, and high-paying career paths in the blockchain space.
    • Analyze DeFi Vulnerability Patterns
    • Execute Automated Static Analysis Tools
    • Draft Audit Finding Reports
  • Skilled — The Protocol Builder
    Transition from building decentralised applications to designing underlying core protocols and performance-focused blockchain infrastructure.
    • Compare EVM and Alt-L1 Architectures
    • Configure Blockchain Client Nodes
    • Analyze Modular Scaling Frameworks
  • Advanced — The MEV & Infrastructure Specialist
    Enter the high-frequency backend of Web3 engineering by mastering Maximal Extractable Value (MEV) searcher dynamics and indexing infrastructure.
    • Deconstruct Proposer-Builder Separation
    • Build High-Performance Subgraphs
    • Formulate Searcher Arbitrage Models
  • Expert / Maestro — The Production Architect
    Scale up to professional enterprise delivery, aligning portfolio structure, technical interview prep, and corporate compliance standards to win premier roles.
    • Architect Institutional Governance
    • Refactor Portfolios for Seniority
    • Master Low-Level EVM Technical Audits

Sample: Demystifying the Block: The Under-the-Hood Mechanics of Trustless Networks

The opening tier, Novice (The Ledger Detective). Deconstructs the foundational elements of a digital ledger and demystifies how cryptographic hashing establishes a permanent, tamper-resistant record.

What's in a Block?

Deconstruct the individual components that make up a single block—index, timestamp, transaction data, previous hash, and current hash—understanding how they tie together.

The Magic of Hashing

Explore cryptographic hashing (specifically SHA-256) to understand how data is transformed into a unique digital fingerprint, rendering arbitrary data immutable.

Lab — Hash Hacker: Learn how SHA-256 turns any input into a fixed-length string and why changing one character breaks the chain.

Ledger vs. Database

Contrast traditional, centralized, write-and-delete databases with decentralized, append-only ledgers to grasp why deletion is impossible in a blockchain environment.

Questions about Blockchain Development

What will I be able to do after this Blockchain Development path?

Understand how blockchains actually work — the mental model behind every crypto and web3 headline you see. Set up a wallet and send real transactions on a live blockchain with confidence, not confusion. Write, test, and deploy real smart contracts in Solidity — not just read about them.

What does the Blockchain Development curriculum cover?

The path is 14 courses, starting with Demystifying the Block: The Under-the-Hood Mechanics of Trustless Networks and ending with Architecting a Web3 Career: Beyond the Hype. Each course is graded across 5 tiers, from Novice to Expert / Maestro.

How long does the Blockchain Development path take?

About 8 weeks at a steady pace, across 14 courses. It is self-paced, so you can go faster or slower.

Do I need experience before starting Blockchain Development?

The path is pitched at intermediate level. The first course opens with: I keep hearing about blockchain and crypto but I don't actually understand what's happening under the hood.

Is the Blockchain Development path free?

Yes. All 14 courses are free in the Breni app on Android and iOS, with no trial limit.

Related learning paths

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