SaaS (Software as a Service) is taking over the cloud computing market. According to Gartner, SaaS growth is averaging $200 billion in year. Customers like SaaS as they only need to pay for what they actually use without owning the underlying infrastructure. Cloud vendors offer very flexible pay-as-you-go pricing models, however their implementations could be quite tricky. Our May-2020 Challenge offers you to implement a typical example of pay-as-you-go pricing rules. Link