Serverless architecture has revolutionized software development by offering scalability and reducing the burden of infrastructure management. However, to harness the full potential of serverless and ensure the scalability and maintainability of your applications, it is crucial to follow best practices.

In this article, we will explore five key practices that will help you develop serverless applications that scale effortlessly and are easily maintainable, even with diverse teams. We will provide clear explanations, real-world examples, and reference links to further resources.

It’s important to note that this recommendations are based on the actual state of the serverless development world.

Although, here at Skail we are working on a much more efficient and simpler way to leverage the serverless benefits to new standards, these recommendations are still very valid.

Modular Design and Microservices

Adopting a modular design approach and leveraging microservices architecture is paramount for building scalable and maintainable serverless applications. Break down your application into smaller, independent modules, each responsible for a specific functionality or service.

This allows for easier development, testing, and deployment, while enabling seamless collaboration among team members.

For example, imagine an e-commerce application that consists of modules such as product catalog, shopping cart, and order processing. By decoupling these functionalities into microservices, different teams can work on each module independently, leading to faster development cycles and simplified maintenance.In this article, Martin Fowler, will give you a complete understanding about how microservices works and answers a lot of questions abou this architecture.

In other words: Fine-grained Function Design.Break down your application logic into small, single-purpose functions. This approach promotes scalability, reusability, and better management of resources. Each function should handle a specific task and be designed to operate independently.

By following this principle, you can take full advantage of the serverless architecture and pay only for the resources your functions actually use.

Optimize Cold Start Times

Cold start refers to the delay experienced when a serverless function is invoked for the first time or after a period of inactivity. During this cold start, the serverless platform provisions resources and initializes the environment necessary to execute the function. Cold starts can introduce latency and impact the responsiveness of your application.To mitigate the impact of cold starts, consider the following techniques:

1. Regular Invocations: One way to keep functions warm is to schedule regular invocations, even if they don’t perform any business logic. By triggering the function periodically, you ensure that the underlying infrastructure remains active and ready to handle subsequent invocations without experiencing significant delays.
2. Provisioned Concurrency: Some serverless platforms offer the option of provisioned concurrency. This feature allows you to specify a minimum number of function instances that should be kept warm at all times. By configuring provisioned concurrency, you eliminate or significantly reduce cold starts, as there are always pre-initialized instances available to handle incoming requests.
3. Function Chaining: In some cases, you can design your application to utilize function chaining. Instead of having separate functions for every step in a workflow, you can combine multiple steps into a single function. This way, subsequent steps in the workflow can benefit from the warm environment created by the initial step, reducing cold start times for subsequent invocations.
4. Background Warm-up: Implement a background warm-up process that periodically invokes your functions to keep them warm. This approach ensures that functions are pre-loaded into memory and ready to handle real user requests. You can use automation tools or scheduled triggers to initiate the warm-up process at specific intervals.
5. Intelligent Scaling: Take advantage of intelligent scaling features offered by your serverless platform. These features automatically adjust the number of function instances based on the incoming request rate. By scaling proactively, the platform can maintain a sufficient number of warm instances, minimizing cold starts during traffic spikes.

It’s important to note that while minimizing cold start times is desirable, it shouldn’t be the sole focus of optimization efforts. Consider the trade-offs and the overall performance requirements of your application before implementing specific strategies. Continuous monitoring and testing can help you evaluate the effectiveness of your cold start optimization techniques and fine-tune them accordingly.

Stateless Functions

In the context of serverless computing, being stateless means that each function execution is independent and does not rely on any previous state or information stored on the server. When a function is invoked, it should include all the necessary input data within the invocation itself, and it should not assume any existing context or data stored on the server.The reason for this statelessness is scalability. 

Serverless platforms can scale functions automatically based on demand, spinning up multiple instances of the same function to handle concurrent invocations. If functions were designed with internal state, it would be challenging to scale them horizontally, as the state would need to be synchronized across all instances, leading to potential conflicts and bottlenecks.

To ensure statelessness, consider the following practices: 

1. Externalize State: Store any required state or data outside of the function itself. You can use databases, object storage, message queues, or other persistent storage options provided by your serverless platform or cloud provider. By separating state from the function, you allow it to be accessed and shared across different invocations of the function.
2. Use Function Inputs and Outputs: Pass all necessary information to the function through input parameters or event payloads. The function should take inputs, perform the required processing, and produce outputs without relying on any external context. This way, each invocation can be treated independently, and the function remains stateless.
3. Avoid Caching Inside Functions: As serverless functions can be short-lived, caching data inside the function may not be beneficial in many cases. It can introduce complexity and potential inconsistency when scaling and distributing function instances. Instead, leverage external caching mechanisms such as managed caching services or distributed caches if caching is required.

By designing your serverless functions to be stateless, you ensure that they can scale horizontally without conflicts or synchronization issues. It enables efficient resource utilization and allows your application to take full advantage of the elasticity and scalability offered by serverless platforms.

Leveraging Managed Services

One of the key advantages of serverless is the availability of managed services provided by cloud providers. Instead of building custom components, utilize these services for common functionalities such as databases, storage, authentication, and messaging.

Managed services abstract away the underlying infrastructure and handle scalability, availability, and maintenance, reducing the complexity of your application.

For instance, Amazon DynamoDB is a fully managed NoSQL database service that offers automatic scalability and high availability. By using DynamoDB instead of managing your own database infrastructure, you ensure seamless scalability and reduce the maintenance overhead.You can get more informations about Amazon DynamoDB here.

Effective Monitoring and Logging

Implementing comprehensive monitoring and logging mechanisms is essential for maintaining the health and performance of serverless applications. Monitor key metrics, such as response times, error rates, and resource utilization, to proactively identify bottlenecks and potential issues. Logging enables you to capture valuable insights about your application’s behavior, aiding in debugging and troubleshooting.

CloudWatch, a popular monitoring and logging service provided by AWS, allows you to collect, visualize, and analyze application logs and metrics. By leveraging CloudWatch, you can gain real-time visibility into your serverless application’s performance, identify potential scalability challenges, and optimize resource allocation.You can access more informations about AWS CloudWatch on this page.

Automated Testing and Continuous Integration

Implementing automated testing and continuous integration (CI) processes ensures the stability and quality of your serverless applications.

Establish a robust suite of tests, including unit tests, integration tests, and end-to-end tests, to verify the correctness of your application’s components and interactions. Integrate these tests into a CI pipeline, where code changes trigger automated builds, tests, and deployments.

Frameworks like Serverless Testing Framework and Jest enable you to write and run tests specifically designed for serverless architectures. By automating your testing process and adopting CI, you can catch bugs early, maintain code quality, and facilitate collaboration among team members.Access here the Serverless Testing Framework documentation.

Version Control and Collaboration

A basic one but fundamental.

Emphasize the use of version control systems and foster a collaborative development environment to manage code changes efficiently. Git, the most popular version control system, enables multiple developers to work on the same codebase simultaneously, tracking changes and resolving conflicts. Implement code review practices to ensure code quality and knowledge sharing within the team.

Hosting platforms like GitHub provide an effective collaboration environment, allowing team members to contribute, review code, and track modifications. By utilizing version control and collaboration tools, you ensure transparency, traceability, and smooth teamwork.

Conclusion

By implementing these five best practices in serverless application development, you can build highly scalable and maintainable software solutions. Modular design, leveraging managed services, effective monitoring, automated testing, and collaboration through version control are essential pillars for success. Real-world examples and references have been provided to support and guide your journey towards developing robust serverless applications that are easily maintained and scalable, even in teams with diverse members. Embrace these best practices and unlock the full potential of serverless architecture in your software development endeavors.