UE.co provides car- and home-insurance sales leads to a country-wide network of salespeople. I was responsible for developing a few data pipelines for use in their next-gen platform. The service would fetch leads from external providers or accept a CSV upload of lead data, scrub the data through half-a-dozen internal services, and deliver the end result to a front-end application which allowed the salesperson to save the list of leads for later. My services were written in Haskell and designed to be highly concurrent, handling something like 60k-70k leads per minute. The bottlenecks ended up being the insert operation into Amazon Redshift, and the third-party APIs.