Front-end (FE) development is highly reminiscent of traditional web (“Web2”) development. This includes the technology stack involved in building out user interfaces connected to blockchain technology.

Just like in traditional environments, FE blockchain developers are expected to fetch data and interact with APIs in order to produce a seamless user experience on a decentralized application.

As a result of the overlap in these core competencies, front-end developers are able to leverage a mature ecosystem of tried and true languages, libraries, and various other tools that will be covered in this section.

Additionally, these similarities contribute to a much more frictionless onboarding process for developers who are new to frontend development. These developers are able to tap into a mature ecosystem composed of developers who eagerly impart their knowledge via platforms such as StackOverflow. This also extends to the availability of well-produced tutorials and documentation for grasping these well-established technologies. Note, however, that this is not the norm in such a rapidly emergent ecosystem, such as Web3, which makes frontend development the most popular choice amongst those new to blockchain technology.

The key principles of front-development require knowing how to structure and style websites, how to make them dynamic with JavaScript and different frameworks, how to manage state within applications, basic design, how to fetch data from APIs and databases, and how to create good web3 user experiences regarding wallets and the interactions with the smart contract backend of your application. One of the biggest differences in web3 FE development is user-authentication as instead of logging in with your email and password or your Google account, you log in with your wallet using a third-party application like Metamask or WalletConnect and protocols like ENS to display information about the user (provided they have an Ethereum domain). If a smart contract contains a state which represents past interactions with the application by the user, you also need to fetch historical data from the blockchain on-demand or maintain a local database with indexed data which is easily queriable by the FE of the application.

As a front-end blockchain developer you need to know what a Contract Application Binary Interface (ABI) is in order to be able to interact with smart contracts on the Ethereum blockchain or on an L2 like Optimism, Arbitrum, Starknet, or ZkSync which are Ethereum-based scaling solutions that we’ll cover in the L2 section. You also need to query data from various APIs to accurately display the price of various assets (if applicable), the user’s balance of ERC20 tokens or NFTs, and various other data you might need from either the blockchain itself or an external database.

Another interesting feature of programming decentralized applications is the need for building applications that are not hosted on a centralized server, to remedy this problem many developers have their web interfaces open-sourced and have many instances of those interfaces on decentralized storage solutions like IPFS, Arweave, and others. In this way, if one of the servers hosting the interface to interact with the smart contracts goes down, users can interact with it from many other different places. It’s also amazing that since the functions are able to be called by anyone, users can interact with decentralized applications from completely different frontends as long as they have the ABI, this allows for massive composability which we’ll cover a bit later.

This roadmap will focus on the frontend technologies that I’ve seen are mostly used in blockchain development today. I’ve used the frontend roadmap, a friend’s tech stack, and my experience as a reference for creating this specialization. If you are a more experienced reader feel free to suggest pull requests to add/edit/remove content or you can suggest changes by DMing me on Twitter or Telegram (@dcbuild3r).