Build/port/rewrite interactive web UI with myriad controls and elements

We are looking for a highly-experienced front-end developer to build a number of front-end interfaces that, effectively, edit JSON data and send the edited result back to a server. We already have fully-functional versions of these interfaces, so you will be working with something that is very clearly defined. The UI logic can, however, become quite complex (for example, there may be a table with 500 rows and 12 columns, where two columns contain drop-down combo boxes, whose contents will change based on the row, with coloring that may differ for each row, and with permissions that may also differ by row and columns-- all of which may dynamically change depending on choices the user may make as the JSON object is edited. The successful candidate is highly experienced and skilled in: * building complex UIs that integrate with single-page browser pages/apps (this project deliverable will be invoked from a pre-existing page through e.g. a button) * writing code with attention to performance in terms of both speed and memory usage * writing code that fully separates styles / css / themes, and makes easily configurable * writing code that is modular, minimal, clearly organized and easy to hand off and maintain * using statically-typed languages such as Typescript, over dynamically-types alternatives * minimizing dependencies on third-party libraries and frameworks * delivering work product that can built as debug (un-minified) or production (minified) versions, and that includes automated test scripts, and that can be fully-built in a shell environment (e.g. bash) with standard build tooling