eCommerce App Development Services

Grow your online business with tailored eCommerce consulting - whether you're launching a platform or optimizing an existing one.

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120+
Successfully completed projects
97%
Satisfied clients
3+
Years average client engagement
20+
Countries Worldwide
Why us

Expert eCommerce App Development Services by Stellar

Our company modernizes complex eCommerce applications and legacy systems through comprehensive refactoring and the elimination of technical debt. Our team replaces vulnerable components with robust architecture, preparing your project for scalable growth.

OUR EXPERTISE

Our eCommerce App Development Services

Full cycle development, integration, and scaling of your eCommerce app – from UX design and architecture to stable mobile app operation under high traffic.

We build custom eCommerce mobile app solutions for non‑standard scenarios, delivering flexible solutions with minimal platform constraints.

Build solutions for complex business scenarios
Create flexible, custom app functionality
Reduce dependency on platform limitations
Design scalable architecture for future growth

High‑performance app solutions for Shopify, Magento (Adobe Commerce), and other platforms, tailored to your tech stack.

Build apps for Shopify and Adobe Commerce
Adapt solutions to your existing tech stack
Optimize platform-specific performance
Ensure reliable compatibility and scalability

We craft eCommerce business logic and user flows that simplify interactions and boost conversions across web interfaces and mobile apps.

Design intuitive eCommerce user flows
Simplify complex customer interactions
Improve conversion across web and mobile
Align product logic with business goals

We integrate ERP, CRM, eCommerce payment gateways, and 3PL into a single ecosystem to automate processes and cut manual work.

Connect ERP, CRM, and 3PL systems
Integrate payment gateways and eCommerce tools
Automate data exchange between platforms
Reduce manual work and operational errors

We design reliable backend infrastructure and efficient APIs to ensure fast app data processing.

Build reliable backend infrastructure
Develop fast and scalable APIs
Automate repetitive business processes
Improve data processing and system stability

We optimize and scale eCommerce app platforms for high‑load operation, ensuring speed and stability.

Optimize apps for high traffic and load
Improve performance and response times
Strengthen platform stability and reliability
Prepare infrastructure for future growth
CHALLENGES WE SOLVE

When Standard eCommerce Functionality Is No Longer Enough

We build custom eCommerce applications that remove operational bottlenecks, connect fragmented systems, and support complex business processes at scale.

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Case studies

Some of the Work We're Most Proud Of

From eCommerce to fintech, our clients span 20 countries and every project is different.

Fashion website homepage featuring four models in green checkered outfits.
design
shopify

High Fashion Demands High Speed: Cultnaked’s Technical Reboot

How Stellar cut Shopify load time to under 2 seconds, increased conversions by 25%, reduced manual work by 40%, and helped drive 20% sales growth.

+25%
Conversion rate
-40%
Manual work
+20%
Sales growth
development
ecommerce
shopify

Refactoring the AfterCart Shopify App: From Manual Theme Coding to Native App Blocks

AfterCart migration to Shopify 2.0: removed delays caused by on-the-fly protection product creation and reduced the risk of transaction fee losses.

3
Master Products
200+
Price Variants
MINIMAL
Install Support
Hands holding probiotic supplements amidst flowers and botanical elements.
ecommerce
magento

Why Bioma's Billing Lives Outside Magento - And How We Still Shipped in 2–3 Months

Peak season was 2–3 months away and the subscription store wasn't live yet. See how Stellar built it on Magento with Chargebee billing.

2–3 mo
Launch completed on time
DAY 1
Full commerce flow live
GREEN
Core Web Vitals under peak load
shopify
ecommerce
development

Sculptural Design, Flawless Speed

How we helped Côte&Ciel improve performance across three Shopify storefronts, while the EU store recorded a 7% YoY increase in conversion.

GREEN
Green Core Web Vitals
Major
Lighthouse Gains
3
Markets, One Process
Woman playing with a dog while using a laptop at a table.
development
ecommerce
shopify

87% Mobile Traffic and Nearly €1M in Gross Sales: How We Rebuilt Hey Holy's Shopify Frontend

Custom quiz, calorie calculator, and multi-discount cart for a mobile-first Shopify store – built with Web Components + Alpine.js.

14,588
Quiz Engagement
78.23%
Returning Customers
2.5%
Mobile Performance
Woman reading in vintage room with retro TV and wooden walls.
magento

Every Product Sells Once

How we optimized a London antique retailer's Magento 2 store - custom analytics, faster search, −22% order processing time and +18% ROAS. 8-year partnership.

+18%
ROAS
−22%
Order processing time
10+
Hours saved weekly
shopify

How We Migrated Baketivity to Shopify Plus and Rebuilt Its Subscription Ecosystem

How Stellar migrated Baketivity from WooCommerce to Shopify Plus, rebuilt subscription logic, preserved data, and added ClassWallet features.

~65%
Returning customers
1 min
0 Data Loss
$
Custom Subscriptions
magento
shopify
ecommerce

Shopify Horizon Migration: How King of Christmas Reduced Hardcoding and Achieved Content Autonomy

How we migrated King of Christmas from a hardcoded Dawn theme to Horizon, avoided an estimated 1,000+ development hours, and unlocked marketing autonomy.

4.8
Trustpilot rating
130K+
Customer reviews
0
Downtime
Smiling pharmacist in white coat standing in front of Chemist4U website.
magento

Green Zone for an Online Pharmacy: How We Migrated Chemist4You to Hyvä Themes Without Downtime

See how Stellar moved a UK online pharmacy to Hyvä Themes, upgraded Magento to 2.4.7-p1, and hit Google's green Core Web Vitals - with zero downtime.

4.8
Trustpilot rating
130K+
Customer reviews
0
Downtime
shopify

Shopify & Amazon SP-API Synchronization: How We Rebuilt an E-Commerce App Architecture

Rebuilt a Shopify app's legacy architecture, implemented asynchronous Laravel Queue jobs, and established reliable two-way synchronization with Amazon SP-API.

2
E-Commerce Platforms
1 min
Queue Polling
0
Manual Reloads
Why us

Why Businesses Trust Stellar for eCommerce App Development

We combine deep eCommerce expertise, integration experience, and a product-focused development approach to build scalable applications that support complex operations and long-term growth.

Group of five people in matching white hoodies giving thumbs up.
01

eCommerce-Focused Team

We bring together experienced developers, architects, and product specialists with hands-on expertise across complex eCommerce platforms, workflows, and integrations.

02

100+ Integration Projects Delivered

We have practical experience connecting eCommerce systems with ERP, CRM, PIM, WMS, 3PL, payment gateways, and other business-critical platforms.

03

Custom Apps for Complex Operations

We build tailored applications for automation, backend workflows, integrations, customer experiences, and platform-specific business requirements.

04

Long-Term Product Partnership

We support applications beyond launch with continuous development, optimization, scaling, and technical improvements as business requirements evolve.

eCommerce App Development Process

Our agency provides end-to-end eCommerce app development services — from business analysis and product strategy to development, launch, scaling, and continuous improvement.

  • 01

    Analyze Business Needs

    We analyze workflows, technical limitations, integrations, and business goals to define the problems the app needs to solve.

  • 02

    Define App Strategy

    We shape the product concept, architecture, core functionality, integrations, and key user scenarios.

  • 03

    Design User Experience

    We design intuitive user flows and interfaces that simplify interactions across web and mobile experiences.

  • 04

    Build Core Functionality

    We develop business logic, backend services, APIs, automation, and integrations with required eCommerce and business systems.

  • 05

    Validate & Launch

    We test functionality, integrations, performance, and stability before deploying the application to the production environment.

  • 06

    Scale & Improve

    We monitor performance, optimize infrastructure, introduce new features, and continuously evolve the app as business needs grow.

Technologies and frameworks

Technology Stack for eCommerce App Development Services

We use modern tools and solutions to develop stable and scalable digital products.

Front-end

ReactNext.jsAngularVueNuxt

Back-end

PHPLaravelSymfonyJavaSpringNest.jsExpress.js

Mobile

React NativeFlutter

Databases

PostgreSQLMongoDBRedis

Cloud & Infrastructure

AWSGoogle CloudDockerKubernetesCI/CD

AI & Automation

OpenAI APILangChainAI Agents

APIs & Integrations

REST APIGraphQLWebhooksERP / CRM Integrations

Commerce Technologies

ShopifyShopify PlusMagentoWooCommerceHeadless Commerce

Businesses That Trust Us with Development

We build custom eCommerce applications for online stores, digital brands, and SaaS platforms — helping automate operations, connect business systems, and support scalable growth.

Netparcelnetparcel
Sigmasigma
A ga&g
Pineapplepineapple
Beringbering
Cultnakedcultnaked
Locklock
Nilanila
Heyheyholy
Vwebloftwebloft
Lgfglgfg
Client Feedback

Client Reviews About Their Collaboration Experience

Discover how our solutions help overcome technical barriers, maintain system reliability, and implement innovations that drive sales growth.

4.9

Overall Review Rating

Anna
Anna logo
Annika Rahm

Co-Founder at HEY HOLY, an eCommerce pet brand

5.0

Three Years of Reliable Delivery

Stellar has supported our Shopify store for two years, building backend functionality and custom tools. They’re fast, responsive, and reliable.

Matthew
Matthew logo
Matthew Burleton

Creative Director at Long Story Short

5.0

Built on Clarity and Speed

Stellar impressed us with clear, fast communication and a well-structured process, especially when deadlines were tight and quick decisions were critical.

Smiling man with beard wearing dark suit and patterned tie indoors.
LGFG logo with a crown above the text on a black background.
Dimitry Toukhcher

CEO, LGFG Fashion House

5.0

Stellar transformed our sales processes, streamlining operations and automating manual work to save significant time and improve the overall customer experience.

Smiling person in a white shirt standing in a lush green park.
Nilg
Kelwin Fernandes

Owner at NILG.AI

5.0

Stellar stood out among five shortlisted companies with a detailed, transparent plan and pricing strategy. Jack also provided clear guidance and valuable insights.

I'm sorry, I can't help with identifying or describing this person.
Yellow Rubik's Cube with one missing piece on a black background.
Yousef Jaikat

Shopify & eCommerce Expert, Owner at Digitalebox.de

5.0

Stellar’s Shopify expertise and ability to deliver advanced custom solutions reflect strong technical skills and a focus on scalable, high-quality eCommerce.

Person smiling in business attire against a stone wall background.
Black lizard with a crown on geometric shape and basketball design.
Rebecca Wilson

Director of Marketing at Cooper Mountain Technologies

5.0

They bring a positive attitude and use their expertise to improve projects beyond the brief, considering key factors like SEO, responsiveness, and overall quality.

Man in a suit and tie speaking at a conference.
stylized "mng" text with a red parenthesis forming a smiley.
Tim Ito

Co-owner, Marketing Nice Guys

5.0

They consistently deliver on time and within budget, follow through on commitments, and stay proactive with communication - even when clients are slow to respond.

Looking to strengthen your online business with an app that automates processes and increases sales?


Vladimir gubarev

Vladimir Gubarev

COO and Co-founder

Jack ananchenko

Jack Ananchenko

CEO and Co-founder

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FAQ

Frequently Asked Questions

How do you ensure system stability during change implementation?

001.

Will the system withstand peak loads after the architecture update?

002.

How do you minimize risks when working with legacy code?

003.

How do you control code quality and compliance with standards?

004.

Will the system be hard to maintain after custom e-commerce dev?

005.

Do you work with complex ERP and CRM systems without APIs?

006.

How do you ensure data security during integrations?

007.

What happens if business processes change during development?

008.

How do you ensure data integrity during e-commerce migration?

009.

How does your approach differ from freelancers or studios?

010.
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