We have a site that lists service availability by postcode search. We send postcodes to a third party API and it returns true/false values for availability for various services. This serves our needs 90% of the time, but the API provider is slow to update and the data is incomplete, particularly with new or niche products. What we need to do is add an additional step in our postcode search function which compares the postcode with our own availability lists - we expect to have 5 or 6 lists of between 10 and 100K postcodes to check against. It then needs to return true/false values along with the main API results, as quickly and efficiently as possible. Looking for someone to suggest a method and then work with our front-end dev to create a solution. Please PM me including rates and a rough idea of the time/work involved.