Backend development in the Web3 space involves building the infrastructure, logic, and data handling components that power decentralized applications and blockchain networks. Here are eight programming languages commonly used by backend developers in the Web3 space:

1. Solidity: Solidity is a programming language specifically designed for writing smart contracts on the Ethereum platform. It is the primary language used for developing decentralized applications (DApps) and implementing the business logic of smart contracts.

2. Rust: Rust is a systems programming language known for its focus on performance, memory safety, and concurrency. Rust has gained popularity in the Web3 space due to its use in blockchain protocols like Substrate (used in Polkadot) and building blockchain infrastructure.

3. JavaScript: JavaScript is a versatile programming language that is widely used for both front-end and back-end development. In the Web3 space, JavaScript is commonly used for building backend components, interacting with blockchain networks, and developing applications using frameworks like Node.js.

4. Go: Go, also known as Golang, is a statically typed and compiled programming language developed by Google. Go's efficiency and strong support for concurrency make it well-suited for building backend systems in the Web3 space, such as blockchain nodes, network components, and distributed applications.

5. Python: Python is a popular general-purpose programming language known for its simplicity, readability, and extensive libraries. In the Web3 ecosystem, Python is commonly used for building backend infrastructure, implementing blockchain protocols, and creating tools for interacting with various blockchain networks.

6. Java: Java is a widely adopted programming language known for its platform independence and robustness. In the Web3 space, Java is often used for building backend systems, such as blockchain nodes, network components, and decentralized applications.

7. C++: C++ is a powerful and efficient programming language commonly used for systems-level programming. It is often employed in the Web3 space for building blockchain infrastructure, developing consensus algorithms, and optimizing performance-critical components.

8. Scala: Scala is a modern, statically typed programming language that runs on the Java Virtual Machine (JVM). Scala combines object-oriented and functional programming paradigms, making it suitable for building backend systems in the Web3 space, such as decentralized applications and blockchain infrastructure.

These programming languages offer a range of options for backend developers in the Web3 space. The choice of language depends on the specific requirements of the project, the underlying blockchain technology being used, and the developer's familiarity and preference.