Fast Healthcare Interoperability Resources (FHIR) provides standard data objects in JSON format for the healthcare industry. Since JSON objects are hierarchical and tree-like, we had a need to defensively 'pluck' fields from our JSON objects and do lots of mapping. We tried jQuery and Underscore and a few other technologies like FHIRPath; but Lodash has been the most well supported, works in the most contexts, has the cleanest syntax, etc. We particularly like the ES6 version of Lodash, where we can import the method names directly, without resorting to * or _ syntax. We got hooked on the 'get' function to defensively pluck fields from objects without crashing our user interface, and have found countless uses for the other lodash functions throughout our apps. Lodash is great for developing and optimizing algorithms.