08 Jun 2023
  • Website Development

Boost Angular App Performance with Singleton Services

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By Tyrone Showers
Co-Founder Taliferro

Introduction - Singleton Services for Optimal Application Performance

In the domain of Angular development, efficiency, and modularity assume paramount significance. As applications become complex, managing dependencies and ensuring optimal performance becomes imperative. A potent tool in an Angular developer's arsenal is the concept of a shared core module. By leveraging a core module equipped with providers for singleton services, developers can amplify code reusability, streamline dependency injection, and optimize the initialization process for services that demand loading at application startup. In this discourse, I will explore the advantages and best practices of utilizing a shared core module in Angular.

core module

The core module is a centralized repository for crucial functionalities and services that find applications throughout the software. Unlike feature modules encompassing components and directives, the core module solely devotes itself to furnishing services and other utility functions. By segregating core functionalities from feature-specific components, developers can attain a heightened level of modularity, maintainability, and code organization.

One of the cardinal benefits of employing a shared core module lies in the capability to define and furnish singleton services. Singleton services are instantiated merely once and shared across the entire application. This approach confers several advantages. Firstly, it guarantees the existence of only one instance of a service throughout the application, obviating redundant initialization and conserving resources. Secondly, singleton services enable seamless data and state sharing between diverse components, facilitating efficient communication and curtailing the necessity for excessive event handling or callback mechanisms.

To implement a shared core module featuring singleton services, developers ought to focus on two pivotal aspects: module definition and provider configuration. The core module should be generated utilizing the Angular CLI command

ng generate module core --flat --module=app

with app representing the root module of the application. By designating the --flat option, we ensure that the core module is generated in the project's root directory, eschewing the need for a separate folder. This choice aids in upholding a lucid project structure and grants effortless access to the core module.

Subsequently, after crafting the core module, the ensuing step involves defining and configuring the singleton services within the module. Services can be generated through the command ng generate service core/my-service, where my-service embodies the service's name. Inside the core module file, the services should be enlisted as providers utilizing the @NgModule decorator's providers property. This configuration guarantees that the services are instantiated as singletons and remain accessible for injection across the application.

It is vital to note that the core module should not encompass any declarations. It is a pure services module devoid of components, directives, or pipes. This design decision fosters a distinct demarcation of responsibilities and forestalls conflicts or duplication with feature modules that might declare analogous entities.

To ensure the shared core module is duly imported and employed within the application, it should be imported in the root module (app.module.ts) utilizing the imports property of the @NgModule decorator. This step establishes the module hierarchy and facilitates the availability of the core module and its services throughout the application.

Developers can attain augmented code reusability and maintainability by harnessing a shared core module with singleton services. As the application scales in magnitude, the core module can be seamlessly extended to accommodate novel services or functionalities without impinging upon the existing codebase. Additionally, the segregation of responsibilities between the feature and core modules fosters a modular architecture that nurtures team collaboration and scalability.


Utilizing a shared core module in Angular, with a focus on singleton services, offers many advantages for application development. By adopting this approach, developers can enhance code reusability, foster modularity, and ensure efficient resource utilization. The core module is a centralized repository for essential functionalities, enabling seamless communication and data sharing between components. Furthermore, the clear separation between the core and feature modules promotes a scalable and maintainable codebase. Embracing the power of a shared core module with singleton services empowers Angular developers to optimize application performance, streamline dependency injection, and propel their projects toward success.

Tyrone Showers