Developing e-commerce applications: costs and scope of work

The scope of work on an e-commerce application depends on its features, technology and integration with existing systems. That is why developing an e-commerce application begins with identifying the needs of the business and its customers. First, decide whether you need a mobile solution, a web solution or both, and then determine the required features and connections to your existing shop.

In this article, you’ll learn about the factors that influence the scope of a project, how to choose the right technology, and the stages of implementation, from planning to roll-out. This will make it easier for you to determine what solution your e-commerce business needs.

Key findings

• Plan the integration of the app with your existing shop and systems to ensure that product and order data is consistent.
• Choose a native or cross-platform solution to suit your customers’ needs, planned features and the e-commerce engine you use.
• Simplify the shopping journey: a clear interface and user-friendly design help customers find products and place orders more quickly.
• Break the development process down into stages, from design through to testing and launch. This will make it easier for you to define the scope of work and prepare the application for further development.

Table of Contents

• Is it possible to integrate the existing systems with the web application?
• A native app or a cross-platform app – which is better?
• Designing a customer-centred interface
• The stages of design, development, publication and maintenance
• Internet Stars: E-commerce conversion

Is it possible to integrate the existing systems with the web application?

Yes. A web application can be integrated with an online shop, a payment system, analytics and loyalty tools. Start with a data map: products, customer accounts, orders and stock levels. Then determine which system is the single source of truth for each type of information. If the shop manages its product catalogue, the application should retrieve up-to-date descriptions and availability from it. Integration does not mean copying the entire back-end, but rather the efficient flow of specific data between systems.

Integrate payments with order processing so that customers can see whether a transaction has been accepted. Analytics can track the subsequent steps in the purchasing process, such as searching for a product, adding it to the basket and initiating payment. This makes it easier to determine at which stage customers drop out. A loyalty scheme, in turn, can display the points balance for both the account and the order. Determine where points are stored and when the app updates the balance. These decisions help to organise the integration before development even begins.

Push notifications help you communicate with customers after a purchase and remind them of your offers. They can alert them to price reductions, sales or abandoned trolleys. Tailor the content to the customer’s situation: a shopping basket reminder should link directly to its contents, whilst a price reduction notification should link to the product. Such notifications can encourage customers to return to their shopping. You should also plan which event triggers the message and what data it requires.

After a purchase, the app can display the order status and send notifications when it changes. For example, information that a parcel has been handed over to the carrier reduces the customer’s uncertainty. A shop and an app using the same database can synchronise changes and stock levels in real time. The customer can then see the most up-to-date product availability across all channels. If you are using multiple systems, you should also plan for error handling, such as when the warehouse system fails to respond.

Before implementation, follow these three steps:

• Identify the system that manages each type of data.
• Describe the events that trigger payments, analytics and notifications.
• Test the scenarios, from adding a product to the basket to tracking an order.

A well-designed integration roadmap helps to select technologies that fit the existing shop, rather than forcing a complete overhaul. It also takes into account the loyalty scheme and promotional messages, without adding tools that the company does not need.

A native app or a cross-platform app – which is better?

The choice depends on the functionality, customers’ devices and the existing shop engine. A native app is developed separately for Android and iOS. For Android, you can use Kotlin and Jetpack Compose, and for iOS, SwiftUI. Flutter allows you to build mobile apps for both platforms from a shared codebase. Kotlin Multiplatform can share up to 70 per cent of Kotlin code between Android and iOS solutions. Choose your approach once you have determined which features must work on each platform.

Launching the app does not mean you have to give up your current e-commerce engine. The API integration allows you to retrieve the product catalogue, prices and orders from the sales platform. In the headless model, the presentation layer operates independently of the shop’s back-end. This allows you to create different shopping experiences on the website, in the app and across other channels. When integrating with Pimcore, specify where product descriptions, images and attributes are generated, and then define how they will be fed into the app.

Omnichannel combines online shopping with in-store service. In the Click & Collect model, the customer places an order via the app and collects it from a chosen location. For this scenario to work, the app must exchange data on products, locations and order fulfilment with the relevant systems. You should also plan for handling changes in availability when a product is sold via another channel.

The legal requirements for e-commerce applications in Poland and the EU depend on the sales model, the type of data collected and the payment method used. Right from the design stage, ensure that information for buyers is clear, data is protected and order processing is transparent.

Before launch, test the purchase process, the login procedure and data exchange with the platform. Analytics will show at which stage users drop out. Integration with a CRM helps link user activity to customer service, whilst ASO boosts the app’s visibility on Google Play and the App Store. Test the Android and iOS versions separately, including after any changes to the API.

Choose the technology and integration method based on the needs of your sales channels, not on trends. This is how you’ll build an app that works seamlessly with your existing shop and supports a range of shopping scenarios. If you’re planning a project like this, find out more about our approach to e-commerce apps.

Designing a customer-centred interface

The interface should streamline the process from finding a product to placing an order. Start the design process by focusing on customers’ needs and the most common shopping scenarios.

User interface and features for customers

91% of internet users expect an online shop to be optimised for mobile devices. The app should therefore clearly display product images, prices, variants and availability. Make searching easier by offering category filters and suggestions. Customers can also find a product by taking a photo with their camera or selecting an image from their gallery. Voice search will be useful for those who prefer to say what they’re looking for. Each feature should assist with a specific step in the shopping process.

On the product page, clearly display the available variants and the Add to basket button. Simplify the checkout process: on a single-page order form, customers can populate their delivery address and telephone number using details from previous purchases. The app can also provide access to previously loaded pages, the basket, the wish list and your account whilst offline. These decisions impact customer convenience and engagement.

Wishlists, saved baskets and loyalty

A wishlist allows customers to save products for later, whilst a saved basket makes it easy to return to a shopping session they’ve started. Design both features so that customers can quickly recognise the items they’ve saved and proceed to checkout. If the app supports user accounts, place the wishlist in an easily accessible location. You can also link it to a notification about a change in a product’s price.

A loyalty scheme should clearly display the balance and how benefits can be used. For example, a customer can see their available points in the basket summary. Tailor the features to your business model: a brand whose customers make frequent purchases might develop rewards for repeat business, whilst a shop selling more expensive products might focus on saving and comparing offers. The interface should support sales and further growth, rather than adding unnecessary steps.

Image and voice search should be regarded as alternative ways of finding a product, rather than separate interface objectives. An e-commerce app can allow users to search for products using a photo taken with the device’s camera or selected from the gallery, as well as via voice commands. Place these options next to or right beside the search box so that customers can easily spot them. A brief prompt can explain whether the customer should take a photo, select an existing image, or say the product’s name or description.

Also ensure there is a clear transition from the selected method to the results. The customer should know that the search has started and be able to return to the search box to amend their query. This ensures that additional search options remain a straightforward part of the shopping experience and do not distract from finding the right product.

The stages of design, development, publication and maintenance

The process begins with workshops and the definition of the scope of functions, and concludes with testing and launch. The implementation of a mobile app MVP usually takes between 3 and 6 months, depending on the scope of the project.

Scope of the project

During the workshops, the team organises business objectives, customer needs and application tasks. It then divides the features into those required for the first version and those intended for further development. This division allows the team to assess the scope of work, interdependencies between systems and the order of implementation. The more precisely you define the features, the easier it will be to plan the subsequent stages of the project.

It’s worth starting a UX/UI project with a mobile-first approach: mobile views are created first, and then adapted for larger screens. Workshops and prototypes help to test the customer journey before coding begins. For brands such as Answear and Homla, the starting point could be various shopping scenarios, catalogues and customer needs. However, do not assume that every brand requires an identical layout.

Once the design has been approved, the developers implement the features and the team tests the user flows. They check the login, search, shopping basket and checkout functions on mobile devices, as well as performance and integrations with the shop’s back-end systems. Once any detected bugs have been fixed, the app is ready for release.

Development time and application maintenance

The delivery timeframe depends on the number of features, integrations and the scope of the first release. An MVP allows you to launch core purchasing features, with further developments based on data and user needs. Not every app requires a full-scale launch. Set priorities so that the team can focus first on the main purchase journey.

Following publication, plan to monitor for errors, carry out system updates and test the shop following any changes. Out-of-date integrations may disrupt payments or the display of orders. Maintenance therefore involves work on security, performance and ensuring that features remain compatible with developments in mobile platforms. The scope of these activities depends on the technology, the systems used and the pace of change within the shop.

If you are planning to develop your own solution, discuss the scope of the bespoke application and decide which features to start with.

An MVP takes 2–3 months to develop, whilst software development takes 3–12 months. Publication on the App Store, Google Play and Huawei AppGallery requires testing and the rectification of any faults.

Internet Stars: E-commerce conversion

Internet Stars supports the growth of online sales through e-commerce conversion, dedicated apps, online shops and automation. Get in touch with the team if your current shop isn’t meeting your customers’ needs, you’re planning a new shopping channel, or you want to integrate an app with your sales processes. Together, we can determine whether the best course of action is to develop your current solution, create a new app or optimise the shopping journey.

Before the meeting, prepare a description of your shop, the systems you use and your key objectives. This will make it easier to define the scope of the project and the features needed to support customers and day-to-day order processing. Start by outlining your idea and the challenges you face. Contact Internet Stars to discuss your e-commerce needs.

Turn your idea into the next stage of the sales process

Before starting the project, define what change the app is intended to bring about: easier shopping, more efficient service or a new sales channel. Choose an objective that you can assess based on customer behaviour. This is a good starting point for discussing the features and further development of the solution.

When developing e-commerce applications, the Internet Stars team helps translate a company’s needs into design and technological decisions. Working on applications, online shops and automation systems allows us to consider solutions within the context of a company’s day-to-day processes. Start by describing the challenge you wish to tackle and your customers’ current purchasing journey.

Do you have an idea for a new online shop, or do you want to improve your existing one? Get in touch with Internet Stars and discuss a solution tailored to your business. Take the first step and grow your e-commerce business the right way.

Frequently Asked Questions

How do you plan the development of a mobile e-commerce app?

First, identify the problem the app is designed to solve and which features must be functional from the outset. Draw up a list of integrations, user types and purchasing scenarios. An app for individual customers is planned differently from a tool for regular business clients. This information helps to describe the project precisely and compare possible options.

Why is it worth developing an e-commerce app?

The app can serve as an additional channel for engaging with customers and make it easier for them to use your services. Before you decide to develop it, determine how you will assess its usefulness: you can monitor user activity, their return visits to the shop or their use of selected features. When creating an e-commerce app, also specify who it is intended for and what task it is designed to perform better than existing channels.

What are the stages involved in developing an e-commerce application?

In addition to the schedule, establish the decision-making process for the project. Appoint a person responsible for approving mock-ups, functional specifications and test scenarios. Also set out the acceptance criteria, for example, the correct flow of an order from product selection to purchase confirmation. Clear rules minimise misunderstandings and make it easier to assess whether the finished feature meets the requirements.

How do you go about planning an e-commerce app project in Poland?

Before drawing up the project scope for a Polish shop, gather information about the product catalogue, order processing and the systems in use. Also, prepare a list of exceptions, such as made-to-order products, sets or different delivery options. These details affect how the application works and help distinguish between features that are essential and those that can wait until the next version.

Which technologies and platforms should you choose for an e-commerce application?

As well as the application’s requirements, consider how content and the catalogue will be managed. If your team frequently updates product descriptions, images or variants, plan where these will be sourced from and who will manage them. Also check whether the chosen platform allows you to develop new features without disrupting the shop’s operations. When developing an e-commerce application, the technology should support day-to-day operations, not just the initial launch of the solution.

A native or cross-platform e-commerce app – which should you choose?

Choose an approach that takes into account the frequency of app updates and the differences between versions. If the user experience is to be similar on iOS and Android, a shared codebase can facilitate consistent feature development. Where each platform requires distinct behaviour, factor this into your product plan from the outset. Also, decide who will make decisions regarding future changes.

An article by

Andrzej Klimek

Owner of Internet Stars since 2008