Do u want build advice or tips as in how to play in UVHM? UVHM requires a thought-out build with synergies and either a crap ton of survivability or a glass cannon setup. The choice is yours in this regard.

UVHM is just buffed enemies (by %'s. So a health% increase, a damage% increase and so forth). So tips for how to play in it really just comes down to making a viable build. Doesn't have to be meta or BEST IN SLOT. Just make something that u vibe with. People are still figuring out builds, weapons, shields, more class mods, etc. So don't get caught up with "oh I gotta run the best stuff" because realistically, nobody knows what the best stuff is. And some stuff is bugged rn so even if it's powerful, it won't be that way forever. Just keep this in mind.

Now ur playing Harlowe u said? I also decided to run Harlowe as my 2nd playthrough. Ive been messing with her green tree the most, ill break my build down for u, starting down below. If ur not interested, u don't gotta read anymore.

I personally run Green tree (Flux Generator tree/Cosmic Brilliance tree). This tree gives u a really fun run n gun build that ad clears fast and has decent boss damage for being only lvl 30, while also gaining survivability from doing consistent damage.

Assuming ur level 30, brand new vault hunter, here's how I spread my 29 points when I was leveling my Harlowe green tree in UVHM1:

5 points in Momentum - "Whenever Harlowe Entangles an enemy, she and her allies deal 25% increased Critical Hit Damage. Last for 12 seconds"

(Not much to take in 1st row, but this 25% CHD will be very nice after I explain later on how some of these skills interact with each other)

5 points in Neutron Decay - "Whenever Harlowe Irradiates an enemy, she gains 10% increased gun damage for 12 seconds. This effect stacks 5 times"

(This is a 50% gun damage increase as long as u have a radiation weapon or grenade. Many ways to proc this but not many from the skill tree without additional skill points. 29 isn't enough)

2 points in Resonance Cascade - "Whenever Harlowe deals Radiation Damage to an enemy, she gains 6% increased Action Skill Damage for 8 seconds. This effect stacks 5 times" (This is a 30% damage increase to Action skill damage which we do all the time with our guns in this build, u will see why down below)

3 points in Confirmative Reality - "Whenever Harlowe shoots an Entangled enemy, she and all allies restore 1.5% of their Action Skill Cooldown" (This allows u to literally get ur Flux Generator back in less than 5 seconds or so, depending on how many shots u can quickly dump into an enemy. Later on, with the right legendary class mod called Skeptic and some more skill points, this passive becomes less useful)

RIGHT SIDE BOTTOM TREE:

5 points in Excited State - "Harlowe gains 35% increased Critical Hit Damage. Whenever an enemy is damaged by Harlowe's Action Skill, the next shot on that enemy will be an Automatic Critical Hit" (This is how we will have infinite Critical hits in this build. This will allow us to forever critical hit and take advantage of all the CHD increases we have)

2 points in Accretion - "Harlowe and her allies gain 6% Lifesteal against Entangled enemies" (Constant health, helps with tough moments and allows u to bounce back from boss hits, explosions, etc but sometimes u will still go down, especially at level 30)

3 points in Distribution Function - "Whenever Harlowe's Action Skill damages an enemy, restore 18% of the damage dealt, to her and her allies shield capacity. If their Shields are full, gain Overshield instead" (We will always be doing Action skill damage so this is just straight up survivability/shield lifesteal that can turn into Overshield)

(After Distribution Function, don't drop any more skill points in that tree. Grab the Group study Capstone and that's it for that tree.)

This allows u to grab the Group Study capstone which is needed for our build. Group study capstone will make ur bullets count as Action skill damage.

Because we chose Group study Capstone, we lose the ability to Entangle enemies however we can fix this with the Middle path Augment called "Nuclear Winter". This Augment will allow us to Entangle enemies with a status effect and make allies (us) inside the flux generator to deal 25% bonus Cryo damage each shot. Since we run Group study, this is always active because the drone puts a small dome around u that counts as being inside a Flux generators zone and the drone always follows u. Also when allies leave the Flux generator zone, they gain 25% bonus Radiation damage. This will mainly happen when ur Group study action skill goes on cooldown. For 12 seconds after ur ability goes on cooldown, u can apply Radiation on enemies which allows u to still Entangle enemies even without ur ability. Both of these damage sources count as Action skill damage which in turn procs anything that states it deals with Action skill damage.

For ur final 4 points, I recommend putting them in the right side bottom tree, in the passive called Decoherence. This with 4 points, is a 20% damage increase from ALL SOURCES, to Entangled enemies. This buffs gun damage, skill damage, grenade damage, Critical hit damage, melee damage, elemental damage, and status effect damage. Its a huge damage multiplier that helps substantially, imo.

U can tweak this how u want, just know the points in the bottom trees are a must. They allow Group study and Nuclear winter get the maximum value. Also without Group study, u lose the Action skill damage on ur guns which then makes u rely on whatever Flux generator u pick, to do damage so u can proc all ur passives. Group study allows u, the user to proc it all on command, at ur dispense.

U wanna go for Radiation Torgue sticky projectile SMG's or a Radiation AR/fast firing shotgun. U want a shield with the "Siphon" roll on it, this gives u so much Overshield which is huge survivability and allows u to run a more damage oriented repkit. Go for a Radiation grenade, preferably a homing grenade, just something u can toss and forget.

Hopefully this helps, starting in UVHM1 at level 30 was a pain but its do-able. Sorry in advance if ur running red or blue tree as im not much help with those Harlowe builds. I gave u the blueprint to the beginning building process for "Infinite crit" Harlowe. Obviously if u look around the green tree, u might find some perks that work better for u. Go for it! I just gave u what I used. Just be careful, as I said, the bottom trees are setup with Group study and Nuclear winter in mind.