How to build a read model with Rails Event Store Projection
Recently I faced interesting challenge in one of our customer’s application. Imagine that you take a test after which you get a personalised reports about your skills level. Existing mechanism for that was time and resource consuming. People had to wait for e-mail delivery with PDF-generated report several hours due to several constraints, which I would prefer not to dive into.
The solution was obvious — lets progressively build read model every time someone answers the question. After the test is done, the report will be available instantly in a web ui.