Common Mistakes in Swift App Development and How to Avoid Them

Swift application development attracts many beginners due to its modern syntax and clear language structure. However, even with a convenient programming language, you can quickly run into problems if you do not pay attention to the architecture, code structure, and data handling. In this article, we will consider common beginner mistakes and practical ways to avoid them.

1. Mixing logic and interface

One of the most common mistakes is placing all business logic directly in the files responsible for the interface. For example, in a screen controller, the following occurs simultaneously:

• processing data
• performing network requests
• changing state
• updating the interface

This approach complicates maintenance. If the logic grows, the file becomes overloaded and difficult to read.

How to avoid it

• Export business logic to separate services or managers.
• Use architectural patterns with separation of responsibilities.
• Follow the principle: the interface is responsible only for display.

2. Lack of a clear project structure

Many beginners create files haphazardly: new classes are added without a system, folders have no logical organization. Over time, this leads to confusion.

How to avoid

• Create folders for models, services, managers, and screens.
• Stick to the same naming style.
• Plan the structure before you start implementing.

3. Incorrect data handling

Another common mistake is storing data without a clear model or transferring it between screens without a structure. Global variables or random dictionaries without typing are often used.

How to avoid

• Create clear data models.
• Use structures or classes to describe entities.
• Minimize the use of global state.

4. Overloaded functions

Sometimes one function does too many things: processes data, formats text, calls network services, and updates the interface.

How to avoid

• Adhere to the principle of “one function, one responsibility”.
• Break long functions into smaller logical blocks.
• Create helper methods for repetitive logic.

5. Ignoring error handling

Beginners often assume that a query or calculation will always complete correctly. Lack of error checking leads to instability.

How to avoid

• Use error handling mechanisms.
• Validate data before use.
• Add logging for diagnostics.

6. Lack of separation of layers

In large applications, it is important to separate:

• interface
• business logic
• data access
• If all these elements are mixed, it becomes difficult to change the design.

How to avoid

• Use a multi-tier architecture.
• Separate models, services, and views.
• Plan dependencies between components.

7. Insufficient testing
Many beginners don’t test extreme cases. For example, what happens if the data doesn’t load or the user clicks a button multiple times.

How to avoid it

• Test different usage scenarios.
• Test logic separately from the interface.
• Plan for handling non-standard situations.

Conclusion

The main problem for beginners is not a lack of syntax knowledge, but a lack of thinking structure. A clear separation of responsibilities, planning the architecture, and careful work with data greatly simplify development.

Swift development becomes more efficient when the code is organized logically, functions perform a single task, and the data has a clear structure. By following these principles, you can create stable and scalable applications.