This would be a great talk, because
Records and Tuples are two new deeply immutable data structures arriving to JavaScript. Currently they are still in Stage 2 and under discussion by TC39, but it's worth to take a look at the possibilities they provide.
https://github.com/tc39/proposal-record-tuple
Abstract
Details
What language would you prefer to present this talk
Would your employer / company host the Meetup for this talk?