Natasha is actually really good with technical things and engineering. It helps when it comes to espionage to be able to hack computers and disable alarms, after all. Not Tony Stark good, but good enough that she could understand how the Iron Man suit works if she ever looked at the schematics. She designed and made her own Widow's Bite/String and even a few of Clint's more specialised arrows.

The thing is, she used to make things that got into the wrong hands and bad things happened. She can understand why Stark decided not to make weapons anymore and Iron Man's mission to hunt down and destroy weaponary of his that were in the wrong hands. That's one of the reasons she agreed to be undercover and keep an eye on him. But. Unlike Stark it's not just a fear of the weapon's she makes getting into the wrong hands, because what she's had problems with wasn't designed to be weaponary. People will make of things what they will. So when she started the new life with SHIELD and onwards she never let anyone knew what she was capable of. Clint is the only one that knows.

How and why? And do the rest of the team ever find out? Does she have to rewire a bomb? Hack computers? Fix something? Anything on technical, scientific minded Natasha.