Ecommerce Architecture: Design and Types

Feb 28, 2023 by

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Carlos Padilla

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Carlos Padilla

This article breaks down the most common ecommerce architectures; Monolith vs. Microservices, Two- vs. three-tier
Ecommerce Architecture: Design and Types
An ecommerce architecture refers to the overall technical design and infrastructure of an ecommerce online store, including the hardware and software components, such as servers, databases, and programming languages.
Systems architectures also include the flow of data between different components and how the website or application is built to handle traffic and perform functions such as processing payments and managing inventory.
Ecommerce architectures can vary greatly depending on the business's size, complexity, and specific requirements. Choosing a particular ecommerce architecture is a fundamental decision. It will impact several critical aspects of the business, like scalability, maintenance, upgradeability, cost security, and performance.

Ecommerce Architecture Types

There are several common ecommerce architecture patterns, including monolithic architecture, microservices, two or three tiers architecture, composable, headless, serverless, or cloud-based architectures.
Architectures have different trade-offs, and the best one depends on the specific needs of the business and the resources available.

Monolith Vs. Microservices Ecommerce Architecture

Monolith Architecture

The monolithic architecture model is a unified system that includes all features in a large codebase. In this type of architecture, the ecommerce solution connects to a database. It contains components such as a user interface, data access layer, and business logic layer.
While monolithic architecture is a traditional method of software development, it has some benefits and drawbacks.
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Pros of a Monolithic Architecture

  • It's simple to implement and maintain as all the functionality is contained in one place.
  • There are fewer external components and less probability of things going wrong because everything is integrated.
  • Developing and testing new features is quicker because all the functionality is in one place.
  • Less expensive to set up and maintain than more complex architectures.

Cons of a Monolithic Architecture

  • As the business and traffic grow, scaling can become challenging and may lead to bottlenecks.
  • Inflexible and demanding to change, making it hard to adapt to new business requirements or integrate with other systems.
  • Updating, testing, or replacing one system piece can be difficult and risky because all the functionality is combined.
  • A failure in one component can affect the entire system, which makes it hard to isolate and fix the problem.

Microservice Architecture

A microservice architecture involves breaking down the ecommerce system into small and independent services that communicate with each other through APIs. The main advantage of this approach is that each microservice operates as a subsystem with its specific business logic. This architecture allows for greater scalability and flexibility.
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Pros of a Microservice Architecture

  • Easier to scale individual services as needed without affecting the entire system.
  • More flexibility regarding technology choices and distribution of tasks among development teams.
  • Microservices can be developed, deployed, and scaled independently.
  • The failure of one service does not affect the entire system allowing for a more fault-tolerant system.
  • Better integration with other systems complementing a commerce website, such as CRM, CMS, or payment gateways. Businesses benefit from best-in-breed solutions without the need to reinvent the wheel.

Cons of a Microservice Architecture

  • More complex to implement and maintain, especially for teams with less experience.
  • There is increased communication overhead, which can slow down the system and increase the risk of errors.
  • Development, deployment, and maintenance can be more expensive than a monolithic one. It requires more infrastructure and specialized skill sets.

Two- Vs. Three-tier Ecommerce Architecture

Two-tier and three-tier architectures are different ways of organizing the components of an ecommerce system. The three-tier architecture has an extra layer between the client and server, allowing for more scalability and new features.

Two-tier Architecture

A two-tier architecture is where the client (interface layer) communicates directly with the ecommerce platform's data layer. This architecture is straightforward but can become limiting as the business grows. It makes it challenging to add new functionality or scale the system.
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Pros of a Two-tier Architecture

  • Easy to understand and work with because all the functionality is contained in the client. It's quicker to develop, add and test new features.
  • Reduces network traffic and improves data processing efficiency by optimizing input-output and using buffering techniques.
  • The server uses transaction control to prevent concurrent modifications to the same records.
  • Less expensive to set up and maintain than more complex architectures.

Cons of a Two-tier Architecture

  • Challenging to scale and may lead to bottlenecks as the business and traffic grow.
  • Inflexible and challenging to change, making it hard to adapt to new business requirements.
  • The business logic and data presentation may be the same for multiple client applications, increasing the need for resources.
  • It doesn't provide an additional layer for protection and validation, making it more vulnerable to attacks.

Three-tier Architecture

A three-tier architecture contains an additional "middle tier" between the client and the server. This middle tier typically manages the client and server data flow. It can also handle authentication, security, and data validation functions.
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Pros of a Three-tier Architecture

  • Each layer can be developed by a separate development team, which gives more flexibility regarding technology choices.t
  • Components can be reused across different platform parts, allowing for cost savings and faster development.
  • It provides an additional layer for security and validation, improving data integrity as the client lacks direct access to the database.

Cons of a Three-tier Architecture

  • Different layers may only be able to handle an increase in traffic or data volume with significant modifications. It makes it difficult to scale
  • A three-tier architecture's development, deployment, and maintenance can be more expensive than a two-tier one.
  • Maintenance and upgrades can be more complex and time-consuming, as changes must be made to multiple layers and components.
  • More steps are involved in processing a request, which can lead to increased latency and slower response times for customers.

Composable and Headless Ecommerce Architecture

Headless Architecture

In a headless ecommerce architecture, the front-end presentation layer of the ecommerce platform is separated from the back-end functionality.
The front-end (head) displays the user interface and handles user interactions. On the other hand, the back-end (body) handles specific functionality such as inventory management, order processing, and payment processing.
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Pros of a Headless Architecture

  • Greater flexibility in terms of the technologies used for the front-end and back-end.
  • Better integration with other systems, such as CMS, CRM, or payment gateways.
  • Better separation of concerns can improve performance, making it easier to optimize the front-end for a faster and better customer experience and the back end for better scalability and security.
  • Future-proofing for more straightforward adaptation to new technologies and emerging trends, such as Progressive Web Applications (PWAs) and voice assistants.

Cons of a Headless Architecture

  • More complex to implement and maintain, especially for small businesses with a limited developer team.
  • Increased communication overhead can slow down the system and increase the risk of errors.
  • Development, deployment, and maintenance can be more expensive than traditional commerces.
  • Requires a different set of skills, expertise, and more robust integration between the front-end and back-end.

Composable Architecture

A composable commerce architecture is an approach where the ecommerce platform comprises small and independent services. They can be combined and configured differently to meet specific business needs.
These services can be developed and deployed independently. Also, they can be composed to create a customized composable commerce solution that can be easily scaled and adapted to business requirements.
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Pros of a Composable Architecture

  • Different services can be swapped in and out as needed.
  • New services can be added to the platform without affecting the existing functionality.
  • Services can be scaled independently, depending on the usage.
  • More control over the ecommerce platform to optimize it for specific business needs.
  • Code and functionality can be reused across different services, resulting in cost savings and faster development.

Cons of a Composable Architecture

  • More complex implementation and maintenance, especially for teams with less experience.
  • The system can slow down and increase the risk of errors because services communicate through APIs.
  • Higher operational costs because it requires more infrastructure and specialized skill sets.

What Ecommerce Architecture to Choose

A well-designed architecture can improve the platform's performance, scalability, and security, making it easier to adapt to new business requirements. On the other hand, a poorly-designed architecture can limit the growth and success of the business.

Consider your Current Architecture

When evaluating the current architecture of an ecommerce platform, it's essential to consider the following factors:
  • Scalability: Can the current architecture handle large quantities of users and transactions? Will it be able to drive future growth?
  • Flexibility: Can the current architecture adapt to new business requirements and changing technologies? Can ecommerce be easily integrated with other systems?
  • Performance: Is the current architecture optimized for fast load times and responsive user interactions?
  • Security: Can the current architecture protect sensitive customer data and transactions from potential security threats?
  • Reusability: Is the current architecture designed to allow code and functionality to be reused across different platform parts?
  • Cost-effective: Is the current architecture cost-effective for development, deployment, and maintenance?
Once you have assessed the current architecture against these factors, you should clearly understand whether it fits your business's needs. If the present architecture works, keep using it. If not, look for an alternative that better fits your business needs.

Find the Architecture that Best Fits your Future Ecommerce Needs

Knowing your business's future requirements allows you to make an informed decision about the architecture and features of your ecommerce platform. This ensures your business's growth and success.
The ecommerce landscape constantly evolves, and new technologies and trends are always emerging. Ensure your platform is up-to-date with trends and tech to keep growing and succeeding.
For example, ecommerce businesses looking for a simpler and cheaper solution can use a monolithic or two-tier architecture. However, companies that need to scale and customize their business quickly may benefit from microservices, headless, or composable architectures.
Modern ecommerce systems could choose three-tier or composable architectures if they need security, performance, and integrations with other systems.

Medusa’s Ecommerce Architecture

Medusa provides a set of open source ecommerce building blocks for developers to build bespoke commerce setups. This way, businesses avoid platform lock-in and gridlocks and can instead start from a scaleable foundation.
Different services in Medusa are independent and can be combined differently. Businesses can add or remove features as needed and easily integrate them with other systems. This allows companies to improve the performance of their ecommerce store and adapt to new technologies and emerging trends.
Medusa allows developers to build and customize ecommerce functionality using pre-built services and APIs rather than starting from scratch. This approach allows for faster development, improved scalability and flexibility, and better integration with other systems.
In addition, Medusa's plugin system allows developers to add new functionality to the ecommerce platform without modifying the core codebase. This system will enable developers to create custom plugins that can be used to add new features or extend existing ones. It allows the platform to be customized to meet the specific needs of a business by completing requirements quickly and easily.


Choosing the correct architecture for a business ecommerce can be overwhelming for developers. They must compare each architecture's advantages and disadvantages before selecting an option that could fit the business's necessities.
Medusa is a good alternative for businesses seeking a modular and open source ecommerce architecture. Its modular architecture allows different services to be combined and configured to meet the business's specific needs.
Using Medusa results in cost savings and faster development, particularly for companies with high levels of customization. It has improved integration with other systems and a supportive developer community for assistance with customization and maintenance.
If you’re interested in Medusa, you can get started by following the quickstart guide.
Should you have any issues or questions related to Medusa, then feel free to reach out to the Medusa team via Discord.

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