Blockchain is a decentralized, distributed ledger technology that allows for secure and transparent record-keeping of transactions and assets. Blockchain is used in many applications, such as cryptocurrencies, supply chain management, and voting systems. Popular blockchain platforms include Bitcoin, Ethereum, and Hyperledger. Click here to read more Test-driven development (TDD) is a software development approach where developers write automated tests before writing the code. TDD can help to improve code quality, reduce the number of bugs, and improve development efficiency. Popular TDD platforms include JUnit, NUnit, and PHPUnit.