Moving complex 3 Tier architectures to the Cloud (re-platforming); can be complicated, especially when you have legacy middleware to worry about. Many large firms will decide that they are going to containerise all applications and move them over to AWS or Azure. This however, is not always the best option, nor most practical. Before moving your legacy systems the middleware integration layer and various dependencies between that functionality, and between applications must be understood. Virtual Machines, Containers, Building Cloud Native New, using SaaS, may all be valid alternatives depending on the application, business logic, and end user requirements. The following slides present information that outlines why a mixed architecture is usually the most reasonable.
Most Containerisation assumes a CI/CD process, or some form of automation. Within that process Agile and Scrum are often used, but in many real-world projects, there is no dedicated Business or Product Owner with domain-logic knowledge, budget and organisational power. The whole point of Agile is to introduce the Business to the Delivery team. If the Business-Product owner role is missing, the project will fail.