My Bossy Billionaire by Ashley Zakrzewski

Who knew that getting on that elevator today and dropping her cup of coffee all over her future grumpy boss would change her whole life?

Lily Stevens needs a new job pronto to pay off her college debt that just keeps getting higher because of interest. This job pays almost twice what her current one does and could put her ahead. Unfortunately, showing up early for this interview with a giant coffee might cost her the job.
Adler Maddox, known for being an arrogant billionaire grump, gets stuck with Lily when the elevator halts to stop, after sending her coffee all over his brand new suit.
The problem: this isn’t the first time they have run into each other, and won’t be the last.