Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 180; Flight Crew Type 19200
Situational Awareness; Workload; Communication Breakdown
ATC Issue All Types; Deviation / Discrepancy - Procedural Other / Unknown
General None Reported / Taken
Environment - Non Weather Related; Human Factors; Staffing
FL370 enroute from ZZZ to ZZZ1; we encountered an Air Traffic Controller that was clearly over saturated because of multiple frequencies or too many aircraft.  Traffic in these 2 areas are returning to normal.  We need more Controllers and frequencies to avoid safety of flight issues.
Captain reported concerns about safety of flight issues due to ATC controllers being under staffed and overworked while having to work multiple frequencies.