The pieces of the blockchain Lego

An illustration of the blockchain Lego (source:
  • Protocol Bricks are the foundational pieces for any blockchain application. They implement the protocols that enable cryptocurrencies, the deployment of smart contracts, the interoperability between networks, and improve their scalability. Some examples of protocol bricks are the aforementioned Ethereum and Solana for L1 smart contract deployment; Avalanche, Optimism or Metis as L2 solutions to improve the performance and capabilities of L1 protocols; bridges for the interoperability and seamless asset exchange between networks; or oracles like Chainlink to leverage off-chain information on-chain. Each of these projects are designed to “do one thing right”. They are not interchangeable (i.e. you must either use one or the other), they can be combined to build complex functionalities, and this is the reason why I like to think about them as bricks more than layers of a stack. The same decentralized application can be deployed over Metis’ L2, leveraging a bridge with Binance to interact with assets held in the Binance chain, and use a Chainlink oracle to trigger actions according to off-chain events. You can combine the bricks to build your very own royal palace.
  • Access Tiles represent the interface between end users and decentralized applications. They offer users a gateway to interact with all of these decentralized protocols and systems. Some examples of Access Tiles are browsers and wallets responsible for managing user identities and offering an interface to interact with the low-level infrastructure; aggregators like Zapper that source information from several projects and systems to offer a global view of the ecosystem; or hosting (PaaS/Iaas-like) projects like Infura or Pinata which offer an entrypoint for DApps and developers to the different networks without them having to worry about operating their own nodes and infrastructure. Access Tiles are general tools, they are not specific for a project or an infrastructure, offering a general interface to access any project. They are your door to the blockchain (ok, and Web3) space.
  • Use case Tiles can be seen as the “websites” of the blockchain Lego. They implement specific use cases leveraging protocol, infrastructure, and middleware bricks for their operation (more about the latter in a moment). They can be combined, but they usually offer a very specific use case, so they are consumed by users in isolation. We see here games like Axie Infinity; NFT/Metaverse proposals like Decentraland’s; DeFi financial services like Uniswap; or NFT platforms like OpenSea. All of them are specialized for their niche and solve a really specific user problem. They usually come with their own interface to interact with the service (minimizing the need of access pieces for the interaction).
  • Infrastructure Bricks (a.k.a L0 protocols) are specialized pieces that implement decentralized protocols and systems to complement blockchain applications. These pieces are more aligned with my own vision of what Web3 is deemed to be. Inside this group we find projects like IPFS or Filecoin for decentralized storage; the Graph protocol or IPLD as foundational pieces to source data from the Merkle forest; Swarm or XMTP for decentralized communication; or Celestia as a data availability solution. Infrastructure bricks offer the missing functionality many blockchain projects lack, helping them build consistent solutions (specially for less financial and more cloud-based use cases)
  • Finally, Middleware Bricks are general purpose projects and protocols built to abstract complex functionalities over simple API/interface for others to use in more complex use cases. Some important middleware bricks out there are frameworks like OpenZeppelin, decentralized identity and naming solutions like ENS, Unstoppable Domains, Serto and Veramo (former uPort); or every DeFi project and protocol providing staking, lending, token swapping, etc. The DeFi ecosystem and its projects are a good example of a box of protocol bricks that can be combined to create really complex financial use cases (take flash loans as an example). Unfortunately, this is out of the scope of this article, and if I may, I will leave this discussion for some other time.
Tiles v.s. bricks

Two important Protocol Bricks

In some of my previous publications I’ve been writing a lot about L0, L1 and L2, but I’ve been neglecting two very important building blocks from the blockchain Lego: oracles and bridges.

Blockchain Bridges

Blockchain bridges are protocols implemented to allow the transfer of tokens and/or arbitrary data from one blockchain network to another. They are a key piece to achieve the interoperability between different blockchain systems, and their state. Blockchain networks connected through a bridge can be of a really different nature: they can target different smart contract technologies (or none), run a different consensus algorithm, and store their state with different formats.

  • Centralized bridges that rely on trusting a small number (federation) of nodes to orchestrate the exchange. Users delegate their trust in a set of centralized players that can interact with the two chain bridges and handle the freezing of the asset in one side and the corresponding minting in the other, as well as the ownership exchange. These implementations are usually fast and convenient, but are more vulnerable to attacks due to the small number of participants involved in the protocol (as reported in recent attacks to centralized bridges).
  • Trustless bridges do not require a centralized infrastructure to operate. They are usually implemented through a decentralized protocol that runs a consensus over a two-phase commit, i.e. it performs the freezing and minting mentioned above in a decentralized manner through a set of smart contracts.

Blockchain Oracles

Oracles build bridges between the state in blockchain networks (or smart contracts) and the outside world. These systems send and verify real-world data (like the real-time price of a stock, or the weather on the moon) and inject this data inside a blockchain network. Oracles are generally used to start on-chain events triggered by real-world occurrences.

Wrapping up!

The blockchain space looks more like a Lego than a stack, where one can combine the available pieces to build whatever they want, need, or dream. In this article I tried to illustrate the different pieces that we can currently find in the blockchain box, zooming in into bridges and oracles, two important pieces for the current state of affairs. However, blockchains and the pieces of this Lego are just a really smart part of the Web3 universe full of many more incredible pieces. Winter may be coming to the markets, but who cares! I can’t wait to see what is the next thing to be “buidl” using all of these Lego pieces



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