This document provides an overview of decentralized applications (DApps) and their development. It defines DApps as programs run by many people that create or use a decentralized network for a specific purpose. Ethereum-based DApps typically have an associated smart contract and a web frontend. The document outlines the key building blocks of DApps and tools for their development, including Solidity, Truffle, Web3.js, and security best practices. It also provides a demo of building a simple DApp using Truffle and discusses additional resources for DApp developers.

1. BlockDev Conference SF 2018
Anthony Chow
Twitter: @vCloudernBeer
Auth0 Ambassador
Intel Innovator
VMware vExpert 2015 – 2018

2. What is a DApp?
Image source: https://tyleryasaka.me/blog/2017/01/14/ethereum-dapps.html

3. Dapp as defined in Ethereum Wiki
 Decentralized application is a program which is run by many
people which either uses or creates a decentralized network for
some specific purpose (e.g. connecting buyers and sellers in
some marketplace, sharing files, online file storage, maintaining
a currency).
 Ethereum-based decentralized applications (also called Đapps,
where the Đ is the Norse letter "eth") typically consist of an
HTML/JavaScript webpage, and if viewed inside the
EtherBrowser the browser recognizes special JavaScript APIs for
sending transactions to the Blockchain, reading data from the
Blockchain and interacting with Whisper and Swarm.
 A Đapp typically also has a specific associated contract on the
Blockchain, though Đapps that facilitate the creation of many
contracts are quite possible.

4. DApp Building Blocks(Macro view)
 Ethereum network
 Smart Contract
 Web Front End

5. Dapp Building Block (Pictorial view)
Image source: https://www.easyeth.com/components-of-ethereum-part-3.html

6. DApp Building Blocks (Micro view)
 Ethereum Virtual Machine (EVM)
 Application Binary Interface (ABI)
 Web3
 JSON-RPC
 Truffle; Embark
 Drizzle
 Solidity; LLL; Vyper (formerly Serpent)
 Ethereum Client (Mist, go-ethereum …)
 Swarm
 Whisper
 Meteor
 Oracles

7. Dapp Development Tools
 Solidity
 Solidity web IDE (Remix; Cosmo.to)
 Solidity IDE (VS code; Atom, Vim ….)
 EtherScripter
 Ganache (formerly testRPC)
 MetaMask
 Web3
 Truffle
 Truffle Solidity debugger

8. Before starting
 Ethereum wiki
 Solidity documentation
 Truffle documentation

9. Smart Contract development with
Solidity
 http://solidity.readthedocs.io/en/latest/
 Layout of a Solidity Source File
 Structure of a Contract
 Types
 Units and Globally Available Variables
 Expressions and Control Structures
 Contracts
 Solidity Assembly
 Miscellaneous

10. Web Front end Development with
Web3.js
 https://github.com/ethereum/web3.js/
 https://web3js.readthedocs.io/en/1.0/index.html
 Ethereum JavaScript API
 Callback Promises Events

11. Smart Contract Security
 Smart Contracts are immutable
 Ethereum is “secure” but smart contract may not be!
 Smart Contract Security Best Practices
 Building robust smart contracts with OpenZeppelin
 Add OAuth2 to the Web Front End that interacts with
the smart contract

12. Development Frameworks
 Truffle
 Embark
 Meteor

13. Build a DApp with Truffle
 Install Node.js (Windows; Mac; Linux)
 Ganache
 Drizzle
 Getting Started with Truffle
 Crating a project
 Choosing an Ethereum client
 Compiling contracts
 Running migrations
 Testing the contract
 Writing test in JavaScript
 Writing test in Solidity
 Interacting with the contracts

14. Putting everything together
 The Pet Shop
Demo.

15. Dapp Developer Resources
https://github.com/ethereum/wiki/blob/master/Dapp-Developer-Resources.md
 Main Resources
 Web3 JavaScript API - This is the main JavaScript SDK to use when you want to
interact with a nodes API
 JSON RPC API - This is the low level JSON RPC 2.0 interface to interface with a
node. This API is used by the Web3 JavaScript API.
 Solidity Documentation - Solidity is the Ethereum developed Smart Contract
language, which compiles to EVM (Ethereum Virtual Machine) opcodes.
 Other Resources:
 Standardized Contract APIs - Standard contract API, which should be used to
make some contract types accessible by other Ðapps. (Not yet finalized)
 Useful Ðapp Patterns - Code snippets which are useful for Ðapp development.
 Dapp using Meteor - This short tutorial gives an intro on how to start building a
Ðapp using Meteor, and also why Meteor is a good fit for Ðapps.
 Useful read
 FAQ - Collection of links, useful for understanding the Ethereum eco system.
 Glossary - Great explanation of Blockchain related terms.

16. Resource for Developer
 Blockgeeks
 ConsenSys
 Zepplein
 Facebook
 YouTube
 Ethereum wiki at GitHub
 Solidity Documentation
 Truffle Documentation

17. Thanks for coming and enjoy the rest of the
conference