This month’s wining answers came from Sriram Dharmarajan at Protiviti, and Srinivas Chikkala from India.
To solve LTT-04, the data from the 4 systems had to be joined together using the IMSI and MSISDN, and filtered with the required parameters i.e., ["A", "01", ("precept 250" or "precept 500" or "precept 750")]. There were also inconsistencies between the “names” in the provisioning and billing systems, that needed some manual reconciliation.
The correct answer was L Berselli, which is illustrated in the attached file.
The next LTT will be published on Monday 20th May.