Diving Into Web3: What Technologists Need to Know - Beginning with Smart Contracts

Katarzyna Hasnik
May 19
2 min read

Updated: Jul 4

1. What Are Smart Contracts?

Smart contracts are self-executing programs that run on blockchains (primarily Ethereum).

They automatically enforce the rules of an agreement between parties, no need for intermediaries.

Use cases: payments, NFTs, DeFi lending, DAOs, voting, supply chain, insurance.
Written in: Solidity (Ethereum), Rust (Solana), Move (Aptos), etc.

Diving Into Web3: What Technologists Need to Know - Beginning with Smart Contracts

2. Example (Simple Solidity Smart Contract)

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

contract SimpleStorage {

uint256 public storedData;

function set(uint256 x) public {

storedData = x;

}

function get() public view returns (uint256) {

return storedData;

}

Dive into Web3 Talents https://web3-talents.io/:

Web3 Talents: Fundamentals of Bitcoin, and Ethereum (public blockchain systems) - Discovery & Define Stage.

3. Smart Contract Templates

Templates help developers deploy pre-built contracts quickly.

Examples:

OpenZeppelin: Trusted library for ERC20/ERC721/ERC1155.

https://github.com/OpenZeppelin/openzeppelin-contracts

Thirdweb: No-code templates for NFTs, marketplaces, DAOs.

https://thirdweb.com

4. Ethereum Standards (ERCs)

ERC-20: Fungible Tokens

Used for tokens like USDC, DAI, UNI.

Every token has the same value and is interchangeable.

ERC-721: Non-Fungible Tokens (NFTs)

Each token is unique. Used in digital art, collectibles (e.g., CryptoPunks, Bored Apes).

ERC-1155: Multi-Token Standard

Supports fungible and non-fungible tokens in one contract. Used in gaming (e.g., Enjin).

ERC-4337: Account Abstraction

A new model for smart accounts (wallets), allowing gasless transactions, social recovery, and programmable wallets.

5. DeFi Projects (Decentralized Finance)

Project Use Case Platform

Aave Lending & borrowing Ethereum

Uniswap Token swapping (DEX) Ethereum

MakerDAO Stablecoin (DAI) Ethereum

Curve Stable asset exchange Ethereum

Compound Lending Ethereum

6. Alternative Smart Contract Platforms

Platform Language Key Features

Solana Rust Ultra-fast, low fees, ideal for DeFi/NFTs

Avalanche Solidity High throughput, subnets for custom chains

Polkadot Rust Interoperable chains, shared security

Aptos Move Safe, scalable, ex-Meta team

NEAR Rust Human-readable accounts, fast finality

7. How Can Smart Contracts Look?

Smart contracts don’t have a “UI” like websites, but they:

Are deployed to blockchain addresses.
Can be interacted with via:
- Web apps using Web3.js or ethers.js
- Tools like Remix, Etherscan, Foundry, Hardhat