We require a simple data scrubbing tool.
User should be able to upload a file containing mobile numbers in csv/txt, the system must scrubb/match/compare the uploaded data against an existing dataset and provide 2 result files for download, one that matched and one that did not match. Also require an option to upload the database.
Note: the primary data to be stored is huge, running into several millions of records, hence the system must be able to handle large data/heavy load. Use of nosql/redis/mongo will be required.