Understanding the MVVM Architecture Pattern

Creating a smooth, scalable app that delights users is the ultimate goal of many startups. But there’s more to this than you might imagine. One of the key aspects many amateurs overlook is architecture.

Just like a restaurant can’t run without clearly-defined roles (with one person cooking, waiting, and taking payments, for example), your app can’t run well without proper Separation of Concerns; but more on that later.

Our goal today is to clue you in on the modern approach to coding architecture and organization. That’s right, we’re talking about MVVM. We’re going to break down the MVVM architecture model, explain why it’s the go-to for top app development specialists, and show you how it all works on the ground.

Why Architecture is More Than Just Code

Many startups simply aim for a “working app.” But that’s a mistake. Here’s why: many new apps, despite “working,” fall massively short of expectations. Not only can they struggle under pressure from users, they can be nearly impossible, or at least extremely difficult, to scale.

Relying on unstructured code (what we call “spaghetti code”) is therefore a recipe for disaster. It makes features more expensive to implement and bugs very hard to fix. 

MVVM is the answer. MVVM stands for “Model-View-ViewModel.” At its core, it’s a way of organizing code so you don’t find yourself tripping over loose ends. MVVM doesn’t just save you a bunch of time and money, it might (just) keep you sane!

What is an MVVM Pattern?

For our purposes, we can break MVVM down as follows:

• Model: the data.
• View: what the user sees.
• ViewModel: the logic that connects it all.

This three-part approach massively simplifies your data flow. Here’s an example:

1. The View asks for data: the View (what the user sees, the UI, in other words) doesn’t hold any data itself. It asks the ViewModel when it needs something, like so: “Hey ViewModel, I need the list of tasks!”
2. The ViewModel gets data from the Model: the Model stores all the data, so the ViewModel has to ask it in turn. Example: ““Model, give me the latest list of tasks.”
3. The ViewModel prepares the data: here, the ViewModel might do a little tidy-up of the data so it’s easier to display. For example, if a task’s due date is stored as 2025-11-11, the ViewModel might convert it to “Today.”
4. The ViewModel sends data to the View: the ViewModel kindly lets the View know the data is ready and sends it over. Many modern frameworks do this automatically, but more on that later.
5. The user interacts with the View: the user will click a button or change something, for example.
6. The ViewModel updates the Model: it’s down to the connector to tell the Model to update the data.

Nice and logical, right? You’re probably starting to see why MVVM patterns win out over older styles.

The Model-View-ViewModel Pattern In-Depth

One of the reasons a Model-View-ViewModel pattern works so well is because it relies on three separate layers. And each layer has its own very clear role. Here’s a detailed breakdown:

1. The Model: The Source of Truth

The Model is your data layer. It is responsible for holding and managing the data and logic. It will be in charge of:

• Business logic
• Data access
• Network calls
• Persistence

Important note: it is agnostic of the UI. In other words: it has no control over what the user sees, only the data and logic “behind the curtain.”

2. The View: The Human Interface

This is your UI layer. The View represents what the user actually sees on their screen. So, it dictates things like:

• Activities
• Fragments
• Composables
• SwiftUI Views
• Widgets

The View doesn’t actually contain any business logic itself. It simply watches the ViewModel for any updates and displays the data to the user. Oh, and of course, it passes new data to the ViewModel, too.

3. The ViewModel: The Mediator and Logic Hub

Think of the ViewModel as your engine, or connector. It’s the middleman between the Model and the View and as such prepares and exposes data streams for the View to consume. It doesn’t actually have any reference to the View, though.

The ViewModel:

• Holds UI logic
• Manages state
• Acts as the entry point for user actions

Why MVVM Works So Well: MVVM Testability and Maintainability

There’s a reason so many mobile developers love MVVM. In fact, there are several. Here are just some of the advantages an MVVM architecture pattern offers:

Simplified Testing

Easier testing means faster improvements and a better user experience. A Model-View-ViewModel pattern offers the best app testing framework there is. Here’s why:

Unlike with other patterns, where the ViewModel has a View reference (for example: view.button.text = "Click me"), the ViewModel doesn’t know what the screen looks like in MVVM architecture (the ViewModel might just say: taskList.add("Buy groceries")). Data binding mobile development makes the View update automatically.

This means you can test the logic without showing a real app screen. No more pretending to click buttons. No more UI. Just simple in-ViewModel testing without the hassle.

Decoupled Development

Just as a lack of a ViewModel View reference makes it easy to alter logic without digging around in the View, this also makes it just as easy to change the View without altering the core logic. Any updates you make automatically translate to other layers.

In other words, product designers can jump in and out of the View and switch things up as much as they like without needing to enter the ViewModel at all. This opens up worlds of opportunity:

• Super-fast iterations
• Stable, easy-to-maintain apps
• Developers and designers can focus on their respective areas

Enhanced Scalability

You’ve just made a bowl of your favorite pasta. You dig in, only to find it tastes “off.” Only, since all the ingredients are mixed up, there’s no way of telling which is the culprit.

This is what happens all the time with spaghetti code. A bug appears, but devs have to go through everything to find out why. 

MVVM relies on Separation of Concerns (SoC). Every part of the codebase has a well-defined job. So, when something goes wrong, devs only have to ask three questions:

1. “Is this a data issue?” - check the Model.
2. “Is the app doing the wrong thing?” - check the ViewModel.
3. “Does it look wrong?” - check the View.

Simple. This massively cuts down on one of the biggest long-term costs of running an app: maintenance.

Data Binding Mobile Development: The Secret Sauce of MVVM

You’ve probably noticed the term “data binding” throughout this article. It’s an important one, so we’ll go over it here.

As you know, in MVVM architecture, the View and the ViewModel don’t directly communicate with each other. But they’re automatically connected. How? Data binding.

This is essentially an invisible two-way wire that keeps the two layers in sync. It’s important to know that different frameworks use different tools for data binding mobile development:

• Android (Kotlin/Java) - LiveData or StateFlow
• iOS (SwiftUI) - @State, @ObservedObject, @Published
• Flutter - Provider, Riverpod, Bloc, or ValueNotifier
• React / React Native - useState, useEffect, useContext
• .NET / WPF / MAUI - INotifyPropertyChanged

The Flow of Data

Here’s a simple chart that shows you exactly how data moves along this invisible wire:

Model → ViewModel (state/data updates) → View (UI)

View (user actions) → ViewModel (data updates)

MVVM vs MVC vs MVP: Comparing MVVM With Other Patterns

MVVM is a massive upgrade on older architecture patterns. We already know it’s much simpler and cleaner. But how and why exactly? Let’s compare MVVM with other styles:

MVC (Model-View-Controller)

MVC architecture was the go-to pattern for a long time and still remains so for some teams. With this style, the Model holds the data and the View controls the UI, just like in MVVM. However, there’s also a Controller, which connects the two. 

This might sound pretty similar to MVVM. But there’s a big difference. This is what devs often call the “Massive View Controller” problem (get it?) As apps grow, Controllers often end up way too big. Devs often add everything, including:

• View setup code
• Navigation logic
• Data formatting
• Network calls
• Error handling

Everything gets tangled up together. This makes it super difficult to:

• Test
• Read
• Reuse
• Fix

MVVM takes a simple approach: it moves logic out of the Controller and into a ViewModel.

MVP (Model-View-Presenter)

MVP was the next step up from MVC. It replaces the Controller with the Presenter. Unlike MVC, the View doesn’t pull data from the Model; it just displays what the Presenter tells it. The Presenter holds the business/presentation logic.

The downside? The Presenter holds a direct reference to the View. This means that any changes in the View require changes in the Presenter, too. That’s very different from MVVM, where the two can be changed independently and update each other automatically. In other words: forget quick testing.

So, MVVM was designed specifically to make mobile development easier to maintain and quicker to iterate. It makes the View passive. Data binding makes the ViewModel completely agnostic of the View - app coding, the easy way!

Next Steps

MVVM isn’t just the simplest architecture pattern for modern app development. Or the quickest. It’s an investment. With MVVM, you open hundreds of doors to stable and powerful long-term app maintenance other patterns can’t offer. 

Why? Simple: MVVM cuts time and costs. It makes it super simple for devs to go in and alter data and fix bugs and equally easy for designers to work their magic without worrying about core logic. This means massive savings over the life of your app. 

It’s time to discover the true power of MVVM architecture. Don’t go it alone. Partner with industry experts at Tapptitude and benefit from immediate access to strategic architectural design and development using industry-best practices like MVVM. This is your invitation to a scalable, future-proof app that’s ready for anything.

FAQs

What is the main goal of MVVM?

Quite simply to achieve a robust Separation of Concerns. Whereas older systems often end up with “spaghetti code”, MVVM avoids it. It cleanly separates the data/business logic (Model/ViewModel) from the user interface (View) and makes it much easier to test and scale the product.

What is Data Binding in the context of MVVM?

This is how the View and the ViewModel interact (considering the ViewModel doesn’t have a View reference). Data binding forms an invisible connection between the two layers that automatically synchronizes data.It allows the View to react to changes in the ViewModel without the ViewModel needing to know anything about the View.

Which modern mobile frameworks use MVVM principles?

MVVM is popular across the board. Modern Android development uses it through Jetpack components like ViewModel and LiveData and iOS with SwiftUI and Combine. Cross-platform frameworks also use MVVM. Especially through  Flutter (using providers/blocs) and React Native (using state management libraries).

Does MVVM eliminate all architecture problems?

No. It’s impossible to eliminate all architecture problems entirely. But it does eliminate a vast number of them. MVVM standardizes the core data flow, which is very helpful. But teams must still be mindful of where logic goes. If you’re not careful you could end up with a "Massive ViewModel". This is why patterns often evolve into layered architecture (MVVM + Repository + Use Cases).