There are differences between testing of software developed internally and third-party products. BelVG testers deal more often with our newly created Magento and Prestashop extensions than with customized products.
When you work for a client, you choose software testing methods depending on a number of hours paid. As a rule, there is enough time to do all positive testing and at least part of negative testing. Testing of own software can last for a long time which is something to be avoided.