Become an Intermediate iOS Developer in 2020 [A How-To Guide]

A beginner or associate level needs to know just to do something but to become an intermediate level you need to be able to do a certain thing in a certain way following best practices. I tried to list some of the things that an intermediate iOS dev should know about.

Advanced knowledge in the language(Swift/Obj-C)

An intermediate iOS dev should have basic fundamental knowledge along with advanced and deep knowledge in languages, preferably in Swift.

Architecture

For architecture most common, used and abused pattern is MVC which isn't well testable and reusable and to overcome the problem there are many popular solution like , MVP, , etc and it's up to you which one you'll follow and implement but I prefer to use MVVM along with , as I found it to be more balanced, less complex and suitable for small to medium level project and easy to implement and follow for entire team. Refer to the following posts about MVVM and design pattern:

MVVM Tutorials

• MVVM + RxSwift on iOS

Design Pattern

An intermediate iOS dev must able to follow a good design pattern and should follow  principal and shouldn't violate any design pattern principal.In iOS these are “must knows” :

• Observer
• Strategy
• Factory
• Iterator
• Builde
• Multicast delegate pattern
• Facade pattern
• Composite pattern
• Memento pattern
• Observer pattern

Refer to , it talks about various design pattern.

Persistency

Data persistency is very important for an app if the internet isn't available and the app doesn't work that's bad if the internet is slow and the app slow that's bad, calling API too many costing developer and user more data cost is bad. There are many solutions, based on your need you may choose your solution, having in mind security, speed, complexity, reusability, support.

• (New Favorite)

Concurrency

A senior developer must know about , 

• How to do ,

• queues.

• Main thread, background thread

Optimization

The Code should be , there shouldn't be any memory leaks, retain cycles, Xcode provides  and  to investigate memory leaks and retain cycles.

Security

Security must be ensured and  must be proper.

Reactivity

Modern apps are very reactive, to handle the reactivity we will need any of the Reactive frameworks. Knowledge of ,  is unavoidable nowadays.

CI/CD

CI (Continuous integration), CD (Continuous Delivery) is a must have knowledge for an intermediate level developer. Tools like , service like , , .

TDD

Test-Driven Development (TDD) is a programming practice that instructs developers to write new code only if an automated test has failed. Writing codes that are tastable, writing Unit Testing is part of it. Writing Unit Tests with  or with third party frameworks like .

Code styling and quality

An intermediate dev should follow any standard style guide like

For linting purpose tools like , for code formating .  for linting storyboard, xib files and  to detect unused Swift code.

SwiftUI and Combine

 and  is the latest and most exciting thing in Apple Development ecosystem, these are excellent frameworks but not so many developers uses it in production as most of them need to support devices before iOS 13, but by the end of 2020, it should be the norm (hopefully). Follow this  to know about SwiftUI quickly.

Not just technical skills

Having a theoretical and practical sound knowledge on these topics probably will make you an Intermediate level dev and to become a senior dev you'll need some improvement on soft skills too.

Let's connect on or or read or v.