I love interconnected stories where characters from one story will be in another one. I always find them fun to read. So it was a no-brainer that when I decided to modernize the Jane Austen stories, that they would all be interconnected.
The easiest way to pull this off was to have Darcy be the CEO of a huge corporation and have most of the other characters either work for him directly or indirectly in some form. But I also loved the idea of characters from other books being best friends. Colonel Brandon and Captain Wentworth both had military service in Austen's version. That makes it easy for them to have met each other during their naval service in my modern version and, since they both were denied their first loves, become instant best friends.
Frank Churchill from Emma has a rather controlling aunt. Edward Ferrars from Sense and Sensibility has an equally controlling mother. Having those two bond together due to similar family situations was a fun connection.
The Elliots from Persuasion were aristocrats (Sir Elliot is a baron). They're in their own class and so it made sense to make them a family of lawyers, dealing with high-end cases. The first chapter of Persuading Him (my modern version of Persuasion) shows Anne Elliot working on a case for Darcy v Wickham (mwahaha).
Another fun fact is that Jane Austen used the last name of Smith rather often in her books. This gave me the fun opportunity to make those Smiths the same person. So, Anne's good friend, Mrs. Smith, in Persuasion is now also the Mrs. Smith that is related to Mr. Willoughby in Sense and Sensibility (I made her a cousin instead of the aunt).