Challenges and Breakthroughs of Public Goods from the Iteration of Ethereum Infrastructure

The Ethereum testnet, as a public infrastructure, reflects many challenges and breakthroughs faced by the blockchain ecosystem throughout its development history. From the earliest Olympic testnet to the modern Sepolia and Hoodi, each iteration of the testnet stems from specific technical needs and changes in the ecological environment.

Early testnets such as Olympic and Morden mainly addressed basic functionality verification and consensus issues. The emergence of Ropsten marked the maturity of proof-of-work testnets, but its security issues also drove the development of the authority proof testnet. Kovan and Rinkeby represent different clients' explorations of PoA, while Goerli achieves true multi-client compatibility.

The latest Sepolia focuses on execution layer testing and addresses the ETH supply issues faced by previous testnets. Meanwhile, Hoodi targets consensus layer testing, providing a more reliable validation environment for the upcoming network upgrade. This division of labor reflects the increasingly refined and specialized testing needs.

The development path of the Bitcoin testnet reflects different value orientations. The latest testnet4 upgrade stems from the community's concerns about the abuse of testnet3, pushing for a "brutal" reset of the testnet to maintain its pure testing attributes. Although this approach is quite controversial, it also reflects the self-correcting mechanism of a decentralized community.

From an economic perspective, a blockchain testnet is a typical public good. To balance openness and the rational allocation of resources, both Ethereum and Bitcoin have adopted some form of "isolation" strategy. It is open to ordinary users for free, while setting additional thresholds for large-scale users to maintain the sustainability of the testnet.

Overall, the evolution of blockchain testnets highlights the challenges faced by public infrastructure in a rapidly developing technological ecosystem. Issues such as how to ensure reasonable resource allocation while maintaining openness, how to balance the needs of different stakeholders, and how to address security threats are all questions that require ongoing exploration. The future direction of testnet development may focus more on modularity and specialization to adapt to the increasingly complex needs of technology and application scenarios.