This talk is a first stake in the ground towards a practice of token engineering: the theory, practice and tools to analyze, design, and verify tokenized ecosystems. We frame token design as optimization design, then use optimization design methodology for token design. Furthermore, we can document emerging patterns for token design. We give a case study: the design of Ocean Protocol. This talk was presented at Ethereum Community Conference (EthCC) in Paris, Mar 8, 2018 Related essay: https://blog.oceanprotocol.com/towards-a-practice-of-token-engineering-b02feeeff7ca