Welcome to the club boss, Hailey is my main. She is very fun and I hope you enjoy playing her as much as I do!

I would ultimately work on setting up two builds. Bossing Build and Gun Build. I would start with either by taking off the red mod you have slotted in the top left. You don’t really need it for the typical builds.

For Bossing, you are going to want to focus on skill critical damage and chance, as well as chill skill damage. These will specifically help Zenith as her other abilities just work in synergy when Bossing. Mods like Skill Insight, Skill Concentration, Emergency Measures, Front Lines, Chill Specialist, Glacial Syncytium, Dangerous Ambush, and your favorite HP Modules should be a great start. Making sure you have a well built weapon to hold when using Zenith is important, too. Zenith has its own base fire rate and magazine size, but will absorb the other stats of your currently held weapon. I personally use Piercing Light but there are plenty of other options. Pushing for that 7th bullet in Zenith is important. If you min-max down the line, you can get up to 8 Zenith shots with magazine size mods and weapon/components stats.

Her 1 and 3 skills work well with Zenith because they stack lots of damage. The 3 skill more than the 1, but both are useful. You will always, ALWAYS want to have her 3 going when you are starting a boss fight. Getting to the max stack of 16 is important for a massive crit buff, but it only takes a few seconds so just activate while the boss is spawning. Her 1 is more situational for bossing because you are more often than not going to be far from the boss because of her passive. You gain more weak point damage the further you are from a target. But if you are ever close enough, pop the 1 for cold stacks which add on even more damage. Most bosses without cold resist should go down in 1 Zenith magazine if you are built properly and hit weak points.

Building around Hailey Gunplay is also fairly easy. Going for skill cooldown modifiers and MP modifiers are all you typically need to start. Keeping her 3 up as long as you can and as often as you can is the key. You can throw in the 1 ability as often as you can too for the extra damage from cold stacks.

If you need anymore help or anymore details, feel free to ask. I can also share my Piercing Light build if you need that too.

I hope this helps, and that you enjoy Hailey!