A Data Lake is not a tool, nor a specific solution or product that a company can buy, install, and use. As a reference architecture, it is an organization’s mode of approach to using data in its operations. How to introduce the Data Lake and stay compliant with industry regulations?
A data lake is a collection of variously structured data coming from different sources and available for different users. It seems that such a solution may mean chaos. Meanwhile, it's used by companies from highly regulated environments, like pharma.