Architecture decision records (ADRs) help keep track of decisions about tech tools and projects. GitHub, ThoughtWorks, and eBay use ADRs to provide a detailed, clear history and guide the future. Losing the context on a decision can make it a "silent, lurking liability" and ADRs avoid that. When developers at fintech startup Nubank needed to choose which database they'd use for its customer interaction system, they didn't rush into the decision. They carefully listed all of the attributes they wanted the database to have — like flexibility and compatibility with existing tools — as well as all the different options, like Amazon DynamoDB and Datomic. For each option, they then listed the pros and cons of each tool.