When a Solution Architect designs the solution, he or she must follow the pillars of great system architecture. The pillars include:
Security - includes perimeter control and data security. You need to use the Dynamics 365 security model, Azure AD, Azure Conditional Access, Data Loss Prevention policies in your architecture.
Empowering end users - the architecture should be open for the users to extend or re-use apps, solutions, or components.
Trust and Privacy - the solution should comply with rules, laws, and privacy regulations.
Maintainability - the solution must be well documented, which helps with its maintenance. Also, the solution should not break from the frequent Power Platform updates.
Availability and recoverability - you need to know the recovery capabilities of the solution and all components. The system must be designed for recovery within the required time.
Performance and scalability - the solution must be scalable and use optimal resources for high performance.
Efficiency and operations - the solution must use resources efficiently to minimize the costs and drive up quality and speed.
Shared responsibility - the users are responsible for application security and operations. At the same time, Azure is responsible for providing infrastructure and security of the cloud services.
Design choices - the system architecture must balance security, availability, efficiency, and performance from one side and the operational costs, delivery time, and agility from another.
Reference:
https://docs.microsoft.com/en-us/learn/modules/becoming-solution-architect/5-pillars
https://docs.microsoft.com/en-us/learn/modules/azure-well-architected-introduction/2-pillars