Explore the world of blockchains and cryptocurrencies in this comprehensive ACCU 2019 conference talk. Delve into the technical aspects of blockchain implementation, consensus mechanisms, and smart contracts while critically examining their potential applications and limitations. Learn about the distributed nature of public blockchains, their immutability, and the challenges they present in terms of data throughput and trust. Analyze the suitability of blockchain technology for various proposed use cases and consider the complexities of smart contract programming. Conclude with a balanced perspective, including a brief look at a potentially beneficial blockchain project. Gain insights from experienced programmer Jez Higgins as he demystifies the hype surrounding blockchain technology and offers a realistic assessment of its capabilities and drawbacks.