%% Last Updated: - [[2021-04-01]] %% Include anything that is vital to the success of the release. An example for this would be the final purchasing page on an ecommerce site or the submission of a contact details form for a request for quote. If it leads directly to conversion, script it and test it. Major site-wide changes require testing across a wide variety of functions. Even the betting giant Tabcorp, Australia largest gaming company, admitted to performance issues when they introduced changes to their site in advance of the 2008 Spring Racing Carnival ([Tabcorp acknowledges betting web site poor performance, 2008](http://thoroughbrednews.com.au/news/story/tabcorp-acknowledges-betting-web-site-poor-performance-36333?section=Australia)). Payment is a high-risk area, so anything touching it should be thoroughly load tested, including the payment calculation and processing engine. The payment processing load may differ depending on the horse that wins the race— if the winner is an outsider (a horse with long odds that seemed unlikely to win), your server will need to process much fewer payments than if a favourite does. Make sure you test for the higher load.