I think the point that both Jennifer and Gdanning are trying to make is that the preposition doesn't depend on the gerund (the "ing" verb -- in this case, "providing"). It depends on the word that comes BEFORE the preposition. There are different prepositions that regularly follow different adjectives. We usually say that people are outstanding (or good, or excellent, or skilled, or incompetent) AT something. We say that people are knowledgeable ABOUT something. We say that people are well-versed IN something. There isn't a reliable rule, unfortunately. You'll need to just observe which preposition native speakers use with these terms. The words "knowledgeable" and "well-versed" have similar meanings, but they take different prepositions. You just have to know what the right one is, or look it up, if you don't know. (Even native speakers occasionally have to look up this sort of thing, when they want to use an expression that they aren't very familiar with.)

At -> He's really good at connecting with others. FIXED EXPRESSION On -> I cannot think of any examples for this preposition By -> By doing yoga you can learn to focus better. He's doing right by her, by admitting that he stole the money. SENSE OF WiTH/BY MEANS OF In -> In doing sports consistency is pivotal. In doing so, he revealed his true nature. WHILE/WHEN Examples for adjectives Spinning wheel A running man passed by me. You can see that the preposition depends on the sense OR the expression that is used: being good/ bad/horrible AT

Hm, but here "outstanding" is not a verb. It is an adjective, meaning "good." That's why "at" is used, just as in "he is good at sports."