A guide to custom web app development

11 min read
April 18, 2023

Websites have come a long way from the static, lifeless pages in the 90s.

Now, websites have the kind of interactivity and functionality that can rival any desktop application.

That’s why they now have a more apt name—web apps.

This article will be your ultimate guide to web apps. We’ll talk about the different types of web apps, how much it costs to develop them, and the process involved.

Types of custom web apps

Before we delve into developing custom web apps, you must determine what type you’re aiming for. There are several different types, depending on your needs, so let’s take a look at them.

Static web apps

A static web app is displayed to the user as is, without any server-side processing.

All the content and functionality are pre-built, with no dynamic content generation or database integration involved.

In other words, it’s no different from the pages of a book, where the words or images are unchanging.

static web app

Source: Thinker’s Cloud

Static web apps are made using front-end technologies like HTML and CSS. Despite their name, static web apps can be interactive thanks to JavaScript code.

But that interactivity is largely local—it shouldn’t involve any calls from the web server.

Because they require no processing, static web apps are very easy to develop and deploy. They’re also cheap to host.

That said, their uses are quite limited. Static web apps are suited for apps where content remains constant, such as blogs and portfolios.

Reference apps like dictionaries or guides can also be built as static web apps.

Dynamic web apps

In contrast to a static web app, a dynamic web app generates content on the fly based on user interaction and input.

Dynamic web pages are structured similarly to static pages, except that they also include placeholders.

These are meant to contain data retrieved from a database or processed via a web server.

dynamic web app

Source: Teleport

For example, when users log in to an app, their credentials are sent to the web server. Their profile information, such as their first name, is retrieved from a database.

This is then inserted dynamically into a static page, which is then returned to the user.

The result is that you’ll see “Welcome [First Name]” when you load the page.

Most web apps are dynamic because such web apps are much more flexible and powerful.

They can be used for anything, including e-commerce storefronts, news sites, and video streaming platforms like Netflix.

Basically, any time you need to retrieve and display data from a database, you need a dynamic web app.

Single-page web apps

A single-page web app (SPA) consists of only a single HTML page.

The contents of this page are then updated dynamically instead of refreshing or reloading the entire page as with traditional websites.

single-page web app

Source: Space0 Technologies

Google’s Gmail is the perfect example of this.

Notice how the surrounding frame of the Gmail interface remains constant—only the middle page gets updated with new content as you read and receive emails.

The main advantage of single-page apps is their speed. That’s because only relevant parts of the page are reloaded instead of the entire thing.

This makes the app more responsive and gives a more native-like feel.

However, SPAs are much more complex to develop. They require both server-side and front-end processing through JavaScript frameworks and APIs.

SPAs are ideal for web applications with high interactivity and constant updates. Examples include messaging apps, social media apps, and data visualization tools.

Multiple-page web apps

Multiple-page web apps (MPA) are the opposite of SPAs—they reload a new page dynamically as the user navigates through them. It’s the traditional way websites work.

In an MPA, each user interaction triggers a new request to the server, which responds by sending a new HTML page to the client.

multiple-page web app

Source: Agilie

Because of the constant back and forth of HTML page requests, an MPA usually delivers a slower and less responsive experience, especially with slower Internet connections.

Such web apps also feel less like an app and more like a typical web page.

However, MPAs are much simpler to develop than SPAs, as processing is done mostly on the server side.

As such, MPAs are ideal for dynamic web apps that don’t require constant updates and extensive interactions.

These include e-commerce sites, reference sites, or some SaaS applications.

Progressive web apps

Progressive web apps (PWA) combine both web and native app technologies to create a fast and stable cross-platform app.

PWAs are built just like any web page using HTML, CSS, and JavaScript. But they also use a service worker, a script that runs in the background and caches content and data for offline access and improved performance.

progressive web app

Source: Diva

They also use web app manifests and JSON files that provide app metadata.

The result is a web app that works and feels just like a native app. It’s also highly responsive and works even when offline.

If your app needs this level of performance and engagement, then go for a PWA.

Even if they look difficult to develop, that’s not the case. Thanks to various tools and frameworks, you can easily create PWAs.

Examples of these platforms include Polymer, Ionic, and Vue.

Cost of developing a custom web app

The cost of developing a custom web app can vary wildly, and it’s impossible to nail down a figure without some specifics.

To give you an idea, here are some estimates from Clockwise Software:

web app cost

Source: Clockwise Software

Your web app’s complexity has perhaps the biggest impact on your costs.

A static web app would be cheaper to build than a single-page, dynamic web app that involves extensive server and client-side programming.

The location of your development team also plays a role.

For instance, according to CareerFoundry, the rate of an American developer is twice that of his Indian counterpart. In effect, outsourcing to India can help you reduce your labor costs by half.

There are also other factors to consider, like system integrations, data migrations, and third-party tools.

To get the most accurate cost estimates, you must thoroughly discuss them with your web development team or agency.

If you haven’t got one yet, you can contact the DECODE team to help determine your app budget.

How to develop a custom web app

Although web apps differ from each other, there are certain basic steps that go into developing them.

Here’s how you put together a typical custom web app.

Do market research

Validating your idea is a critical first step for your project. This lets you know if you have a profitable app idea or are just wasting your time and money.

The best way to test your idea is through market research.

At its core, market research is all about asking the right questions:

  • What problem is your app trying to solve?
  • Who will use it?
  • How will it help them?

To answer these questions, you must talk with your end users through questionnaires, surveys, and focus group discussions. You can also rely on published research and statistics.

mobile app market research

Source: Goodfirms

It’s also worth doing a competitor analysis. This involves checking what other apps in your space are doing. The goal is to improve upon their strengths and avoid their weaknesses.

Write a software requirements specification

You can’t build a house without a blueprint, right? The same goes for a web app.

In this case, you need a software requirement specification (SRS), which outlines the functional and non-functional requirements of the web app. Here’s a short breakdown of their differences:

functional vs non-functional requirements

Source: Plan.io

Functional requirements refer to what your app does. These are the features and functionality that help fulfill its purpose.

Non-functional requirements are about how your app does things. It mostly involves performance and security metrics.

Aside from requirements, the SRS should also outline the constraints and limitations of the project. This ensures that developers can prepare for it adequately.

Determine which tech stack to use

Your tech stack refers to the technologies and tools you’ll use during app development.

This covers the programming language, integrated development environment (IDE), frameworks, databases, and third-party tools.

tech stack example

Source: K&C

Picking the right tech stack is crucial because every piece of technology has its pros and cons. Getting the wrong one in your project can introduce issues or hinder the app outright.

It’s also important to consider your team’s expertise with it. If you need to use tech your developers don’t know, you must factor in learning time.

Or, you can hire an outside developer (but it’ll cost you).

Decide on a development methodology

Your methodology is the way you organize the web app development process. It determines the phases of your pipeline and, more importantly, when you should do them.

Different methodologies suit different projects, so it’s best to familiarize yourself with a variety of them.

For example, the Agile methodology breaks up app development into several mini-phases called sprints.

It allows teams to improve their app iteratively, which makes it the best option for complex projects.

agile methodology steps

Source: Asana

In contrast, the Waterfall methodology arranges development phases sequentially. It’s straightforward to implement but prevents teams from backtracking to a previous phase.

Thus, it’s suitable only for smaller projects with set requirements.

waterfall methodology steps

Source: Lucidchart

Then you have the Spiral methodology, which is also iterative in nature. It is suited for larger, more expensive projects since risk management is its strongest suit.

It’s also ideal for rapidly releasing software updates.

spiral methodology steps

Source: Sitesbay

Whichever methodology you use, make sure everyone is comfortable with it. These are only effective with buy-in from the team.

Design the web app’s user interface

An app isn’t all just about functionality—its interface is important, too. Studies show that a well-designed UI can increase conversion rates by up to 200%.

So, it’s worth paying extra attention to app design.

A good place to start is with the design guidelines provided by Apple and Android.

These are fantastic resources for achieving the right look and feel for these platforms. Plus, following them will always lead to usable and effective UIs.

web app UI

Source: Google Material 3

From here, it’s best to create wireframes to flesh out your designs. These are fantastic tools for letting people evaluate your design and improving on it iteratively.

This gives you a better chance of nailing down the best look and feel for your app.

It doesn’t even need to be polished—something rough will do.

low-fidelity wireframe

Source: CareerFoundry

Moreover, you can take an approved wireframe and turn it into a mockup, prototype, or even assets for the final app.

Develop the front end and back end

Once everything is planned, the next step is implementing it into code. For most web apps, this involves developing both the front-end and back-end.

The front end is the UI of the web app—what the user interacts with.

It’s built using web technologies like HTML, CSS, and JavaScript. This is also where you incorporate your app design.

The back end is where the processing happens. For instance, it’s where data is retrieved from a database and inserted into a dynamic web page.

Back-end technology is much more varied, which includes PHP, C#, SQL, Python, and more.

web app backend

Source: DDI

Development is arguably the step that will make or break your app. This is why it’s important to get the best team for the job (like DECODE).

Perform quality assurance

The final step before you launch an app is to ensure it works as intended. You do this with thorough testing.

Testing is critical because software is never 100% bug-free right off the bat. Conducting tests allows you to spot errors, ensure compliance, and make an overall great web app.

For the best coverage, it’s best to use both automated and manual testing approaches.

manual vs automated testing

Source: Science Soft

The good thing about automated testing is that it’s repeatable. That allows you to execute a large volume of tests easily. The only drawback is that it can only evaluate quantitatively.

That’s where manual testing comes in. It’s still the only approach when testing subjective metrics, such as usability and aesthetics.

Need help developing your web app?

If you’re looking for the best web app developer for your next project, DECODE fits the bill.

We’ve developed dozens of successful projects in industries ranging from healthcare and hospitality.

And both big firms and smaller startups trust us with their development needs, including Asseco SEE, Microsoft, and Royal Caribbean.

And with our pool of 70+ professionals with diverse talents, we can tackle any challenge you throw at us!

Interested? Contact us today and schedule a free consultation.

Written by

Marko Strizic

Co-founder and CEO

Marko started DECODE with co-founders Peter and Mario, and a decade later, leads the company as CEO. His role is now almost entirely centred around business strategy, though his extensive background in software engineering makes sure he sees the future of the company from every angle. A graduate of the University of Zagreb’s Faculty of Electrical Engineering and Computing, he’s fascinated by the architecture of mobile apps and reactive programming, and a strong believer in life-long learning. Always ready for action. Or an impromptu skiing trip.

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