Service Companies: How Do You Manage PTO Requests, Sick Call-Offs, and Team Visibility?

Looking for feedback from other service-based companies on how you're managing attendance, PTO, vacation, and employee visibility. We have a mix of employee types including: • Field staff/technicians/crews • Sales staff/estimators • Office/admin staff We're trying to find a better system for handling both: Planned time off Vacation/PTO requests submitted in advance Approval workflow before time is granted Visibility into who is scheduled off and upcoming absences Last-minute absences Sick notifications or same-day call-offs Avoiding situations where an employee texts only one person who may miss the message Ensuring the appropriate people are notified automatically We're looking for something that works well across both desktop and mobile, since field employees may primarily use phones while office staff and managers may use desktops. Ideally, we'd also like good team visibility so managers and employees can quickly see who is out and avoid scheduling conflicts. For those with similar infrastructure, what are you using? What has worked well, and what would you avoid?