Code Architecture for Web Apps: How to Choose
Defining the web software architecture of your future product is among the most important decisions you have to make — you can face serious difficulties in case you choose the wrong basis for your project. Without proper architecture, your code can simply turn into a mess, and that’s it! We are here to help you to avoid such a problem, so keep reading to learn what web software architectures exist and which of them are the most suitable for you.
How Right Web Software Architecture Can Help Your Project
Before we will tell you all the details about the most popular web software architecture patterns, let us quickly explain why you actually need to choose one of them. So, building web software architecture means developing a plan describing different decisions and aspects which are important to the software itself. And here are a few reasons why web software architecture and decisions you make while building it are a must:
1. Reducing risks
The development of any product is exposed to diverse risks, and, unfortunately, your project is not an exception. Lack of knowledge and experience, potential hacker attacks, human errors… Obviously, this list is not full. However, strategic technical decisions can help you and your team to avoid the risks. For instance, training, using specific patterns in the code, and regular reviews can deal with the security risks, while the lack of knowledge can be solved by hiring experienced specialists or even an entire outsource team. As a result, the potential risk level will get lower.
2. Reducing development costs
Right software architectural decisions can significantly reduce the costs of your web product development. Here are several examples of how the expenses can be reduced:
- It is easier to maintain the software, as the code structure is visible. Therefore, a team will be able to find bugs quicker, so the testing phase will take less time and money.
- Having a clear automated testing policy can also considerably decrease the cost of dealing with the developer’s mistakes.
- Instead of creating new specific features, you and your team can use third-party services. This trick will save your time and, therefore, budget.
There are many more potential advantages, but they depend on your project, so we can’t provide you with more details. But there is one universal rule we can share with you: make your decisions as clear and simple as possible. This strategy will reduce the risk of misunderstanding and, therefore, decrease the development costs.
3. Creating a product which works within the quality constraints
The quality constraints highly depend on your product, so, again, we can’t provide you with the exact list. However, here are some examples:
- Performance (time for requests to response for certain functionalities)
- Resistance to errors (if there is a miscalculation in a certain part of the system, it should be detected quickly by another part)
- Availability (for instance, the system should be available at least 99% or even 99.9% of the time)
- Robustness (if there is a failure in one of the modules, it won’t cover the rest of the system)
Each of these and other potential constraints can have a huge impact on the structure of the system. Moreover, certain quality constraints may even require specific technologies to be used. But in any case, clear web software architecture simplifies developing a product which will work within the constraints without any problems.
What Web Software Architecture Patterns Exist
Those three reasons which we mentioned in the previous paragraph should be enough for you to start searching for the right web software architecture. To make your life easier, we have prepared a list of the most common web software architecture patterns.
The MVC, or Model View Controller, pattern divides app architecture into three parts. The first one is called Model, and it is all about data and core functionality of the product. The second one is View, and it displays info to users. The last one is Controller, and it deals with the input from users. You see, this web software architecture pattern has a very logical name! MVC is not the best choice for small applications, but it can be useful in case you and your team work on a web app.
- The development process is faster, as the MVC pattern supports parallel development
- The MVC pattern allows creating multiple views for the Model section, so the code duplication is very limited
- Changes in the Model section don’t affect the entire architecture
- The View and Controller sections are closely coupled with each other, so if you modify one of them, the other one will be affected
- Since MVC implies new levels of indirection, the solution becomes more complex
The event-sourcing web software architecture pattern means that instead of storing the model’s current state, you and your team will have to pay attention to the events happening to the model. For instance, a user changes their address. In this case, the value won’t be stored in the “Address” column of the database — instead, there will be the “AddressUpdated” (or something like this) event together with the new value. The old one can also be kept there. The event-sourcing web architecture works good for applications with complex domains, user interfaces, and asynchronous systems which have asynchronous data flow.
- The architecture is extended easily
- The architecture is adaptable to complex environments
- This pattern can provide an audit log out of the box
- In case the modules can affect each other, the testing can be pretty complicated
- It is impossible to simply edit the database to deal with the wrong data — the pattern needs some discipline
Using a set of microservices to create your product actually means developing a lot of different applications which will work together. Each of the developed microservices will have its own task, and can be created without regard to other microservices. Communication is the only dependency you and your team will have to work on, and the messages must be backwards-compatible. The microservices architecture can work for websites with a lot of small components, quickly developing web apps, and for products which development teams are located not in one place, but across the globe.
- Every microservice can be developed and maintained separately
- The microservice architecture is easy to scale
- Ensuring communication can be complicated, especially when different microservices are developed by different teams
- The web product will have more potential points of failure, as an action performed by a user may involve several microservices
- Splitting tasks into independent units can be challenging — in some cases, it may be even impossible
CQRS, or Command and Query Responsibility Segregation, is a pattern which implies usage of both read and write operations (they must be separated!). The data is supposed to be stored in different locations, and, besides, models used for read and write operations should be different. This is how this pattern works: a user performs an action, and then the application sends a command to the command service. This service retrieves all the essential data from the database, makes all the required manipulations, and then stores it back. As a result, the read service receives a notification, and the read model is updated. The CQRS web architecture is a good choice for apps with complex domains or apps which expect a lot of reads.
- CQRS allows avoiding complex queries
- Read models can be adapted to specific scenarios
- Command models can focus on validation and business logic
- It can be pretty complicated to synchronize everything
The layered pattern is a very popular choice, and its idea is splitting the code into a set of layers, with a certain responsibility for each of them (for instance, checking the data for consistency). Here are the most frequently used layers: presentation, application, business, infrastructure, and database. The presentation layer is all about graphics design and user interaction, and the application one is devoted to all the logic which product needs to meet its functional requirements. The business layer involves logic and models which are specific to the business problem you and your team are trying to solve. Then, the infrastructure layer contains the code essential to manipulate the final layer — the database one. The layered architecture is often used for developing e-commerce web apps and desktop apps.
- The pattern is simple, well-organized, and visible in the project
- Most developers have experience in working with this pattern
- All the objects of a given kind are kept together, so in case they require any changes, you will find them very quickly
- The layers are consistent in different projects — you may be able to use them again for another product
- It can be hard to organize the project in case it becomes too global
- Changes from a low-level layer can affect the high-level one, as there is no dependency inversion
What to Do After the Pattern is Chosen
Everyone knows that after you release the product, it is essential to test, check, and update it on a regular basis. Well, the same rule works for the web software architecture — after you choose the pattern and design the architecture, it is essential to check it every time a new component is created and integrated. Consider your web architecture unstable and review it in line with the speed of your team. Otherwise, even the most well-designed structure will bring you no benefits.
To check your code architecture, we recommend you to implement feedback loops. They should be used at the end of every stage of the development process, and, as a result, you and your team will understand if the code meets the requirements.
A really good web software architecture should be solid, flexible, and easy to maintain. And one of those patterns we described above can help you to deal with this task! However, keep in mind that it is pretty common to combine several patterns — for instance, CQRS and event-sourcing architecture sometimes look good together. We say “sometimes” because the choice of pattern or patterns highly depends on your product — there is no available universal solution. But if you have any questions or need a consultation regarding what web software architecture pattern to use, don’t hesitate to get in touch with us.