Regression testing of software services

A computer comprising:

• a memory configured to store responses by one or more first downstream service calls and a plurality of requests;
• a processor, connected to the memory, and the processor configured to perform:
• for each request of the plurality of requests, performing:
• while processing, by a first version of a service, said each request of the plurality of requests performing:
• intercepting the one or more first downstream service calls made by the first version of the service;
• and
• for each downstream service call of the one or more first downstream service calls, providing, to the first version of the service, a first particular response of said each downstream service call of the one or more first downstream service calls that was previously recorded while processing said each request of the plurality of requests in a production environment;
• wherein processing, by the first version of the service, said each request of the plurality of requests comprises processing said each request of the plurality of requests based on the first particular response of at least one of the one or more first downstream service calls;
• processing, by a second version of the service, said each request of the plurality of requests to generate a second particular response to said each request of the plurality of requests;
• processing, by the second verison of the service, said each request of the plurality of requests to generate a third particlar response to said each request of the plurality of requests;
• calculating an amount of difference between the third particular response and the second particular response;
• including said each request of the plurality of requests in a particular set if the amount of difference does not exceed a threshold;
• and
• calculating a statistic based on processing, by the first version of the service, each particular request of the particular set.

One or more non-transitory computer-readable media storing instructions that, when executed by one or more processors, cause:

• for each request of a first plurality of requests, performing:
• while processing, by a first version of a service, said each request of the first plurality of requests performing:
• intercepting one or more first downstream service calls made by the first version of the service;
• and
• for each downstream service call of the one or more first downstream service calls, providing, to the first version of the service, a first particular response of said each downstream service call of the one or more first downstream service calls that was previously recorded while processing said each request of the first plurality of requests in a production environment;
• wherein processing, by the first version of the service, said each request of the first plurality of requests comprises processing said each request of the first plurality of requests based on the first particular response of at least one of the one or more first downstream service calls;
• processing, by a second version of the service, said each request of the first plurality of requests to generate a second particular response to said each request of the first plurality of requests;
• processing, by the second version of the service, said each request of the first plurality of requests to generate a third particular response to said each request of the first plurality of requests;
• calculating an amount of difference between the third particular response and the second particular response;
• including said each request of the first plurality of requests in a particular set if the amount of difference does not exceed a threshold;
• and
• calculating a statistic based on processing, by the first version of the service, each particular request of the particular set.