More appropriately: what has this organization learned?
This is an exciting team with a great foundation ... but we can't rest on those laurels, and stuff happens. Based on the time + resources spent on a team that limped into last year's playoffs and may limp out of this year's: the Padres are not immune to mistakes and/or bad luck. However you label it, what's important is how the FO applies what it has learned -- from their successes, as well as their failures.
Avoid the premature long-term signings. It's no stretch to say the team has attempted to unload these guys, but low performances at a premium price tag for multiple years has been an issue. It will be interesting to see how they handle a guy like Cro. Examples: Wil Myers; Eric Hosmer.
Be patient with young talent. Regardless of whether you prefer prospects to be capital or roster pieces, it seems we've jettisoned and/or promoted a handful of players too early, only to have them bloom elsewhere or flame out at the MLB level. This includes making choices that allow a young player to develop and get to Petco. Examples: Luis Patiño; Trea Turner; Chris Paddack; David Weathers; Hosmer 'blocking' France, Reyes, Naylor; Galvis as a stopgap to FTJ.
Not everybody is -- or needs to be -- Fernando Tatis, Jr. Players contributing before they can buy booze is an exception, not the rule. While this collaborates with being patient, it also speaks to the idea that a good team doesn't need to be a collection of phenoms. The collateral damage to chasing 'loud talent' is that solid players are overlooked and ... bloom elsewhere. Examples: Eric Lauer; Cal Quantril; Luis Urías; Ty France.
You can never have too much pitching. I believe we've relied on too many bullpen arms and hopefuls for the rotation. Despite the volume of high-ceiling options, it's obvious we haven't had enough dependable arms to throw MLB innings for 60 games, much less 162. Examples: bullpen games and more bullpen games.
Hot talent lava works(!) but can cool. I enjoyed the commitment to building up the farm system and developing talent. As the window opened, we let all that cold air into the farm system and there's not nearly as much lava bubbling these days. Personally, I'd love to see us get back to acquiring talent rather than just spending and plugging holes. Example: our farm system ranking is in the lower-half -- and dependent on Gore recovering.
I don't know how to do polls, so I'm instead asking: are any of these more important than the others? how many did I miss? how about game/roster/pitching management?
Please note: I realize some of this is based on revisionist-style history, or moves that made sense but have backfired (i.e. Quantril in the package for Clev). I'm focusing conceptually, rather than on individuals or individual moves. I believe that's exactly what is needed when making smarter decisions in the future.
If you've read this far: you owe me a beer.