What is Modular Programming? All the pros and cons of the method


We have already broadly spoken about programming as part of software development's front-end and back-end structure. Today, we will continue the coding topic, looking at object and functional programming. We will pay special attention to modular programming as an old yet still extremely popular method of programming. Let us show you why and how you can benefit from module programming in your software development.

Object programming vs. functional programming

We will start our story by explaining the differences between two main paradigms: functional programming and object programming.

Functional programming

Being the oldest existing programming method, functional programming builds the systems by focusing on their functions. Those system functions can be:

  • stored in a variable
  • passed as an argument
  • returned from a function

The functions are called first-class citizens because they are the base of all operations.

For this article, we will only go into a few technical details. However, it is safe to say that functional programming is great for the server side of software, data manipulation, or web crawling.

Object-oriented programming

Object-oriented programming (OOP) uses code to achieve the desired result step-by-step. OOP groups functions with their variables into objects. To better describe how objects work, let's take a phone as an example of an object:

Object: phone

Functions (methods in OOP): calling, sending text messages, use of applications

Variables (properties in OOP): color, make, model

Due to its accessibility, object-oriented programming is widely used by most developers.

Modular programming- a revolution or an old paradigm?

Modular programming is an alternative not strictly belonging to any of the methods mentioned above (although many claim it is one of the object-oriented programming methods). This method has been present in software development since the 1960s. Yet, it is still considered one of the most convenient programming methods. Modular programming is closely related to object-oriented and functional programming. They all have the same aim of dividing the construction of large software systems into smaller pieces.

In modular programming, a given software's functionality gets divided into manageable independent parts. In other words, the developer closes all elements of one functionality in one module. Independent modules can be bound together and stacked to form the whole application. Let us look closely at what modules are.


As briefly mentioned above, modules contain certain functionalities. Every module performs different operations, and combining them allows for software creation. This approach is beneficial for producing many applications mainly because it allows for the preproduction of certain functions and reusing them to create new software. How exactly? Let's take an example of a notebook. If you buy a plain lined notebook, you are not necessarily interested in the interior because it is the same in every lined notebook. The only element that changes is the cover. A print house could easily have one saved file called Lined Interior and would not have to create a new interior each time they want to release a new lined notebook. What a save of the most crucial resources - time and money! It is a simplified representation of how reusing prewritten code works. However, are there other benefits to module programming?

How can modules help in software development?

Let us return to the coding world and look at how creating and using modules in software development can benefit the development process. 


Thanks to module programming, the code is straightforward to read. However, it is noteworthy that modules can be long and complex, with many arguments and variables. Therefore it takes an experienced developer to conduct straightforward and clear modules. Nevertheless, if performed correctly, the modules should be easier to read than monolithic codes. 

Easy testing and faster fixes

Every code needs to undergo testing before the software can be released. After all, the end product must work. Module programming allows testing separate parts of the whole software. It saves time (again) and ultimately makes it easier to perform the tests. It also allows one to focus on more complex functions that need more attention during the testing phase. Also, once a faulty module is identified, it is simple to rewrite or replace just that one defective module, not the entire application.


This function of module programming has already been briefly mentioned. However, it has more aspects worth mentioning. Firstly, thanks to modules, which can be pulled by using interfaces or libraries, the maximum size of created application or software is smaller than what it would be without using modules. Secondly, modules can be used within one piece of software and in creating other projects. 

Low-risk updates

You might be wondering about issues that may come with updates. What if you make a faulty change in the module used in many more places or even applications? It could break the code and cause more havoc than the monolithic codes. It is a valid concern. However, there is more to a programming module than simply populating it. Every module programming project has a defined layer of APIs protecting from making changes inside libraries. Therefore, without changing APIs, there is a low risk of accidentally breaking the code.   

Are there any cons to modular programming?

Every method has disadvantages, and it would not be objective if we skipped them. That is why let us briefly explain the possible obstacles in creating modular software:

  • programming module sections is a task for a skilled professional; therefore, it may be a lengthy and costly task not only to do it but also to find an appropriate developer/company who will do it properly
  • as much as programming modules usually saves time, it may be time-consuming to test them and ultimately result in a lower program's efficiency
  • modules created by different developers have different styles. They may create uneven and inconsistent software if combined.

Even though modular programming is not a perfect method, it is still a prevalent approach among many developers. Any disadvantage can be mitigated if one learns the programming module art properly.

Sailing Byte has been a modular programming company for years

With countless advantages of modular programming and our extensive experience in the software development market, we can safely say that Sailing Byte is an expert in module programming. We design modules in advance and plan what to include in every one of them so they are well-written and as simple as possible. We test the modules thoroughly to make them 100% bug-free when applied to the software. Finally, we reuse models creating our style of developing high-quality software perfectly tailored to our clients' business needs. Book a call today to find out about all possibilities of modular programming we can offer while building your software.




Łukasz Pawłowski

CEO of Sailing Byte

I am running Sailing Byte - a Software House that focuses on Laravel and React, but doesn't constrain to it; we have also done projects using C#, Unity, Flutter, SwiftUI and other. My role is to organize and deliver software using Agile methods - by providing experience and technical knowledge and proper set of tools to cooperate with our clients.

During our journey I have met all kind of great people, who also took part in our success - both our clients and business partners who are part of our success and who also helped us to elevate Sailing Byte as polish software house, that is providing quality development not only in eastern Europe, but also UK and USA.

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