Typically Fiserv leadership (and I use that term loosely) cuts the lowest performers based on stacked rankings or performance indicators AND the highest paid. So you may have top performers being cut who have healthy (and often well deserved) salaries - maybe they have been with the company for many years. That's how they select. You never want to be at the top and at the bottom.
This is the best advice you'll get about working at Fiserv. It's not true that low performers are ignored, but it's very true that the highest performers also get laid off just because they became too expensive for the company.