Lost (RIP) was a master of backstory.
Starting with the first scene of the pilot, the show followed the cardinal rule of screenwriting: open in the midst of a crisis, and introduce your characters by showing how they react to it.
Having crashed on an island, Jack opens his eyes, gathers what he can of his situation, and springs into action doing what he does best: saving other people.
And once the audience sees the plane wreckage and starts to meets the survivors, they want to know A) what happened on the plane? and B) who are these people?
Using parallel stories (one taking place on the island, and one taking place before the crash), the show jumped back and forth between two equally compelling plots each episode.
I struggle a lot with back story. I don't want to overload the beginning with information that's not relevant, but I also don't want to provide too little information and risk alienating the reader. If the audience doesn't understand why someone behaves a certain way, they might lose patience or stop caring about the character altogether.
How do you balance "present time" versus backstory? Do any novels or TV shows inspire you in this regard?