What are the benefits of using design patterns?

Design patterns help the programmer apply already-proven approaches to common problems. There will be less time wasted in searching for the proper solution or fixing a design issue after a sub-optimal implementation. Anti-patterns provide additional guidance for avoiding common design flaws.

What are some of the key design principles?

The key design principles include SOLID, DRY, KISS, POLA, YAGNI, and POLP. These principles are widely recognized as good guidance for object-oriented programming, but they can be applied equally well in other programming paradigms.

What problem does the open/closed principle solve?

The open/closed principle encourages the programmer to design a system that is easy to extend without having to modify the component that is being extended. It promotes better reusability of software components.  

Why is interface segregation important for software reusability?

Interface segregation promotes a minimalistic design for interfaces so that software components can implement the respective interfaces more easily. A large, complex interface is difficult to implement and it makes the component less reusable.

What are the simplest ways to develop maintainable software?

The simplest way to is to adhere to the general design principles such as KISS, DRY, POLA, and SOLID.

What is a good practice for avoiding over-engineering and bloated software?

The best way to avoid over-engineering and bloated software is to only implement functionalities that are absolutely necessary according to the YAGNI principle. Also, keep it simple (KISS) and avoid duplicate code (DRY).

How does memory usage affect system performance?

When the system allocates more memory, it also triggers the Garbage Collector (GC) more frequently. Garbage collection is a relatively expensive operation and, hence, it can slow down the system. Avoiding over memory allocation is usually one of the best ways to optimize application performance.