Revoking a software system upgrade without data loss

A non-transitory, computer-readable medium storing one or more instructions executable by a computer system to perform operations, comprising:

• determining that verification of an upgraded software system is unsuccessful;
• stopping a recording of inbound and outbound calls in the upgraded software system;
• following a roll back of the upgraded software system, starting a previous software system version;
• temporarily blocking inbound external communications for the previous software system version;
• redirecting outbound external communication;
• replaying the recording to re-create data in the previous software system version;
• replying to external communication requests with responses from the recording;
• and
• checking number ranges for completeness.

A computer-implemented system, comprising:

• one or more computers;
• and
• one or more computer memory devices interoperably coupled with the one or more computers and having tangible, non-transitory, machine-readable media storing one or more instructions that, when executed by the one or more computers, perform one or more operations, comprising:
• determining that verification of an upgraded software system is unsuccessful;
• stopping a recording of inbound and outbound calls in the upgraded software system;
• following a roll back of the upgraded software system, starting a previous software system version;
• temporarily blocking inbound external communications for the previous software system version;
• redirecting outbound external communication;
• replaying the recording to re-create data in the previous software system version;
• replying to external communication requests with responses from the recording;
• and
• checking number ranges for completeness.