Solidity smart contract project ideas for beginners

Learning a programming language by building projects is one of the best ways to learn it. Solidity is not exempt.

Getting started

One of the most frequently requested questions after learning the fundamentals is where to find projects to develop for practice, because Web3 is still in its infancy and there isn't a lot of tutorial content and resources to help newcomers.

If you are learning Solidity or smart contract programming, I'll be sharing some of the projects I've done so far in this article and how you can build them too. These projects teach you the fundamentals of writing smart contracts as well as typical patterns, vulnerabilities, and difficulties. You are welcome to tweak them however you want.

Tools and frameworks to be familiar with

You might want to become familiar with these tools and programming languages in order to better plan how you can build these projects.

A basic understanding of the blockchain and Web3
Solidity (a programming language for building smart contracts)
Remix (a web3 Integrated Development Environment/IDE)
OpenZeppelin (a popular and useful smart contract library)
Web3.js and Ethers.js (optional)
Web3 frameworks like Truffle and Hardhat (optional)

Solidity smart contracts you can build

Hello world contract: “Hello World” is one of the first lines of code that programmers write. Likewise, you can write your hello world in solidity just like you do in any other programming language. Build a contract that says "Hello, world." Writing this will teach you the fundamentals of building a blockchain project, how to organise your Solidity file's layout, how to declare contracts and functions, and other key language features.
Counter-with-Timer contract: You can create a smart contract that functions as a counter; it needs to have increment, decrease, and view functions. The increase and decrease functions ought to be time-limited so that they reverse an error message once the deadline has been reached. To make it more intriguing and intricate, feel free to modify and incorporate more features.
Student registry smart contract: Imagine that you are a school owner that needs a register to keep track of every student's information. You wish to save that information in a smart contract. Create a smart contract for a student register that allows you to record student information (including name, reg no, and maybe date of birth and class). To edit the information for registered students, you need another function. Of course, there should be another function to view every student you have registered as well as another to delete a student's record. Because you don't want anyone to be able to do this, you should make sure that only the school administrator can add and edit students. However, you can make the others available to everyone so that students can see if they are registered. An owner modifier could be required. You can use a struct to organize student information and a mapping to link students to their data.
Auction contract - There are many different kinds of auctions, but the English auction is the most common because the highest bidder gets to purchase the item. Build a time-limited auction contract. There are a few points to take into account: it should be time-based, only the highest bidder wins the auction and receives the item up for grabs, and the seller receives payment in return. This contract should adhere to typical auction guidelines. You can also include modifications, such as a condition that a certain number of bidders must be present before the auction can end. An NFT may be used as the auction item.
To-do contract - You can create a Web3 version of a todo list project, which is undoubtedly one of the programming projects that is built the most commonly. It should have the ability to add tasks or to-dos, update or edit them, check them off as completed, delete them, and of course, view the tasks (this can be one task or all the tasks). You can add additional features like a task counter to display how many tasks have been added and completed.
Voting contract - Having fair elections and voting is one of the good uses of Web3. Create a contract that allows individuals to vote for their preferred candidates; it must be time-based, each voter may only cast one vote, and only the appointed body may add candidates (because the candidates must be approved). The total number of votes for each choice should be visible to everyone. Voters should be checked, and they might need a passphrase or a voting token. Feel free to modify. It is totally your design decision.
Lottery contract - Create a lottery contract where anyone can contribute money, and the winner takes home the entire pot. You can set a restriction stating that only a specific sum may be deposited in the lottery purse. You can add your own flair to it. The winner must be chosen randomly, and the owner is not eligible to receive the prize. Add any other features you desire.
A whitelisting contract with Merkle-Tree - A Merkle tree is a tree-like data structure used to more securely and effectively encode blockchain data. The root contains the hash of all the data (leaves and nodes) that are stored there. A list of addresses should be included in your Merkle Tree contract, and you should be able to check whether an address is on that list (it should also check if the address is whitelisted). Only addresses that are whitelisted should be allowed to mint your NFT.
ERC20 Token - Make a token that adheres to the ERC20 specification. This token ought to be transferable to different addresses. It ought to have a name, a symbol, and a fixed total supply. Either start from scratch or utilize the OpenZeppelin contract. I strongly recommend you build your own from scratch before making another with OpenZeppelin. Don't forget to mint tokens to your address.
ERC721 Token-One of the buzzwords of Web3 is NFT. Your own NFT can be created! It could be anything—your image, your grandma's image, etc. Make your NFT token, deploy it to the network, and mint it. You will be introduced to decentralized storage using IPFS or Pinata. Put it up for sale on Opensea (don't worry, they have a testnet). You can extend this by creating an NFT collection.
Staking contract: Staking is a well-known concept in Web3 and decentralized finance. Your contract should allow users to stake an amount of money. There should be a minimum amount that can be staked. It should be time-bound—no one should be able to withdraw their money until the deadline has passed. You can have functions to check time left to withdraw, to see the total amount staked so far, and even the amount staked by individual accounts.
Multisig wallet: A cryptocurrency wallet that requires two or more private keys to sign and send a transaction is known as a multi-signature wallet (abbreviated "multisig"). With this kind of digital signature, a group of two or more people can sign papers together. Create a multisig wallet that needs the consent of many owners in order for withdrawals to be authorized. Everyone can deposit, but only the proper ration (for instance, 2 out of 3 owners, 3 out of 4 owners, 5 out of 7 owners, etc.) can approve a withdrawal.
A swapping contract: Build a swap contract that can swap between two tokens or a coin and a token. You can create the two tokens yourself. You can also build a pricing oracle that establishes the exchange rates for the tokens. You should build your contract from scratch and then build another swap contract using Uniswap or Pancakeswap routers.

Other projects you can build include

A vault contract
A crowdfunding contract
NFT marketplace
A DAO
A decentralized exchange(DEX)
An Ether wallet containing ERC20 tokens
A factory contract of any smart contract

Conclusion

Of course, there are a ton more projects you can build, but these can help you gain the necessary knowledge to be regarded as a professional in creating smart contracts. Don't only build and keep your code on your local computer—push it to Github and your portfolio. Make sure to talk about the things you are building so that people are aware of your skills.

Additionally, never take smart contract security for granted, as even a small mistake might result in significant losses. Make sure to check against hacks like the re-entrancy attack. Even the brightest developers may miss security problems these days because they are difficult to spot.

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Thanks for reading and I look forward to seeing the projects you build.

Until I come your way again,

Adios!