# #100DaysOfWeb3: Decentralized Application Development

A decentralized application(dApp) is a software application that connects smart contracts with UI. They’re backend codes deployed to the blockchain networks. Frontend hosted in decentralized storage like [Filecoin](https://filecoin.io/), [IPFS](https://ipfs.io/) among others.

the characteristics of dApps: decentralized, deterministic, turning complete, and isolated. The dApp backend communicates with the Ethereum blockchain and can't be changed.

## Why dApp Development

***Benefits of Dapps development***

* Zero-downtime: once deployed on blockchain the network as a whole is able to serve clients looking to interact with the contract
    
* privacy: you don’t need to provide real-world identity to deploy/interact with dApp
    
* resistance to censorship: no single entity on the network can block users from submitting transactions
    
* complete data integrity: Data stored on the blockchain is immutable & indisputable thanks to cryptographic primitives
    
* trustless computation/verifiable behavior: smart contracts can be analyzed & are guaranteed to execute in predictable ways without the need to trust a central authority
    

***Drawbacks of dApps***

* maintenance
    
* performance overhead: scalability
    
* network congestion: nodes are interrelated if one has an issue it will affect the other plus difficult computations
    
* user-experience: low adoption of web3 due to bad user experience...you can’t interact with a smart contract without frontend
    
* centralization: networks are not fully decentralized
    

## Types of Decentralized Applications

***Decentralized Finance(DeFi)***

* [Uniswap](https://uniswap.org/)
    
* [AAVE](https://aave.com/)
    
* [ALEX](https://www.alexgo.io/)
    
* [Dao project that takes project ides](http://bullperks.com)
    

## Development Environment Setup Options

***Ethereum IDEs***

* [Remix](http://Remix.ethereum.org): widely used but try other IDEs find one that is flexible for you
    
* [EthFiddle](http://Ethfiddle.com)
    
* [ChainIDE](https://chainide.com/)
    

***writing a smart contract***

* solidity [documentation](https://docs.soliditylang.org/en/v0.8.11)
    
* declare the license (identify the owner/standard) - use any license i.e MIT. without it, it will plug an error...have a license
    
* declare solidity version of code: pragma ^0.8.11 (use the latest version). Highly dependant on contracts you’re using some could have been declared absolute for older versions
    
* state contract: the contract is like a class in other program languages. declare the name of contract: voting system have a ballot.
    
* struct is like a user-defined variable(state & local variable - global). Struct is like a custom variable that has a data type of an address. uint. Within a struct, we have other data types.
    
* constructor input value before deployment: top priority functions should be inside a constructor's
    

Thank you for reading through my article on this series. I will be dropping more articles linked to my **100DaysofWeb3** journey. You can leave a comment or suggestion.