I was a Vi one trick a long time ago(wasn't very good though), I recently (unfortunately) picked up league again recently, and I have had some decent success with Vi in the jungle.
I've had a consistent problem playing against Zac and other similar tank engage junglers that can easily match my roam. What do you guys do/build? Is it just bad Queue luck, or is my mindset not correct to try and win those games?

My play style is pretty passive- I try to focus on full clearing, and I typically don't do a sub 6 camp gank unless the positioning is perfect. Even then, I will typically wait until I can get and cover vision around first drag/or hit lvl 6 before I start looking for full commit ganks.

I've always believed the best way to win as a jungler isn't to try and snowball and obliterate every game, it's to have high CS and regularly play and prioritize objectives. My job shouldn't be to win other people's lanes for them. I will still gank frequently if the timing is right, but I'd rather go get 3 camps, a drag, herald, or something else, instead of committing a bunch of time to a single kill and getting someone else fed.

When do you guys do first back? Is there a specific gold target you're going for? How often do you counter jungle/invade?
When playing against zac or someone with a really strong gank, do you just go somewhere else to support a different objective?

Who are our most problematic matchups? What actually makes the most consistent impact? Is it my passive, objective based playstyle, or is the balls deep fighter style?

Every time I've tried to match a jungler with a better blind gank/roam, we lose the fight or a ton of tempo.

Used to be Plat 1/d4 a long time ago, now I'm climbing up from Silver after account elo got reset. currently at Silver 2 as of today.

Current win rate with Vi is 55%.

This is my typical itemization:

1- Triforce 90%, eclipse 10%

2- Black Cleaver

3- Guardian Angel (ahead). Sundered sky (behind).

The rest are pretty conditional.

new vi player here in emerald, tried out both critality and brusier build and i found myself liking aspects of both (critality damage, brusier tankiness) but felt like neither really suited my playstyle so i decided to cook something off meta,

the idea is going eclipse first cause its cheaper then triforce but gives u a shield for surviability and max health damage that stacks with your w making you a tank melter unlike critality, then going berserker greaves alongside w max second for objective shred and camp clear (i average 8.5 cs per min on vi with this build) then going shield bow second for crit and the shield, with these 2 items, when you go into a fight you will proc your eclipse shield first then your passive shield, stacking the shield but the shields procs are staggered which means serpant fang only works on one of them, and then shield bow give you a lifeline shield in which time you can proc both shields, suprisingly i found i die less with this build then bruiser,

finishing off the build go ldr and i.e for damage and last item go guardian angel if fed or blood thirster if you need damage or deaths dance if against assassins.

tried this build on an alt and did well and these are my first 3 games with this build on my main, feels really good to me, might not be meta but honestly i think its really good in terms of a middle ground between bruiser survivability and critality damage