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December 22, 2023 - 6 Min Read

Serverless Applications 101: A Basic Overview and Best Practices

Advantages, challenges, and best practices of serverless applications.

Khawaja Shams


What Are Serverless Applications?

You can travel the whole world without owning a plane. All you need is an internet connection, a credit card, and a wild imagination on where you want to go—and you can buy an airline ticket to get there. The benefit here has little to do with owning the plane—because while it is expensive to buy, it is even more expensive to maintain. Next time you travel, think of all the maintenance you didn’t have to do, the design choices you didn’t need to make, and how all the safety precautions have already been taken for you. Personally, I forget to get gas half the time in my car, but I am glad I am not responsible for ensuring that my plane has enough fuel for the destination and the 14 backup plans I did not need to worry about so I could focus on my vacation!

That in a nutshell is a serverless architecture. You do not need to worry about what CPU type, how many instances, which AZs, etc. are needed to store or process your data. It just happens magically behind the scenes. It’s cheaper, more effective, more secure, and more available. 

Understanding Serverless Architecture

The best serverless services are the ones that blend so well in the background that you don’t even realize you have them! Many of us think that our enterprises are not using serverless because they are all-in on Docker or EC2. The Amazon Machine Instances (AMIs) for EC2 and the containers for your Fargate service are served from S3 without you even realizing it. 

Serverless services like Lambda help you decompose complex monolith applications into purpose-built microservices you can use to have a more modular and adaptable architecture. DynamoDB allows you to scale from 1 TPS to 1 million without ever having to worry about the number of instances. This also illustrates how serverless is so much more than serverless functions! You can have serverless services for your compute, storage, databases, workflow management, messaging, and caching needs. 

Advantages of Serverless Applications

Serverless services offer the fastest time to market for your applications. They eliminate the barriers to entry that typically show up in the form of cost or engineering complexity. 

Easy scalability

Get Going. Keep Going. captures the essence of serverless. Serverless services can scale from 1TPS to 1 million TPS without complex configurations. DynamoDB scaled to over 100 million TPS for Amazon Prime Day, while most Amazon engineers did not have to worry about how to build a very large scale database. 


Serverless services scale to zero and offer a pay-per-use pricing model. This means that when your services are idle or if your product does not take off, you do not have to empty your wallet to cover your cloud bills. 

Enhanced performance

Serverless services bake in all the best practices for security, availability, and even performance. These three are more intertwined than most people realize. When you run out of capacity, it impacts your availability and performance. Serverless services scale automatically so you can get consistent performance even during your busiest peaks! 

Hands-off server management

Why waste time managing servers when you have a business to build or an app to improve? Serverless architectures eliminate distractions! 

Challenges of Serverless Applications

Serverless architectures are often better–but you still have to put some thought into the design of your overall application. That said, many of the problems people typically talk about in serverless architectures are also present in alternatives: serverless just makes them more obvious and easier to debug. 

Cold start problems

Cold start problems are not unique to serverless. Serverless just makes it more obvious. Consider an EC2 cluster with autos-caling turned on. By the time you detect a spike, ask for new instances to pop up, and have those instances enrolled in your load balancer as target hosts, your existing capacity is carrying the additional load for minutes. This is a different form of cold start. Momento offers the best of both worlds by having a warm pool of capacity that we can deploy to your cache to absorb spikes instead of waiting for new EC2 instances to pop up. 

Too many microservices to keep track of

Because serverless is easy, customers often get carried away building many microservices and lose track of how their end-to-end workflow is functioning. To address this, we highly recommend investing in IAC (Infrastructure as Code) and Observability (like tracing) from the beginning. 

Security concerns

Serverless is actually good for security. Momento has security best practices built in and an SOC Type II report. We have end-to-end encryption and authentication by default. Many serverful services default to no authentication and no TLS (Transport Layer Security). Consider ElastiCache vs DynamoDB. In ElastiCache, a default deployment does not have passwords or TLS. However, DynamoDB requires IAM authentication and supports TLS by default without any configurations. 

Best Practices for Building Serverless Applications

Going serverless is easy! You don’t have to go all in at once – and you can incrementally move your applications to serverless models. The best place to start is with new apps that you are writing. 

Leverage managed services

There is a serverless service available for every part of your workflow, from compute to storage to databases to caches. Apply the serverless litmus test to ensure that the services are really serverless and not just posing as serverless—and really pay attention to your specific workflow needs to decide the most suitable solution.

Double down on Infrastructure as Code

Microservices explosion is real! If you don’t have IAC, you will quickly lose track of things. Sometimes, it’ll feel like it is slowing you down—but it will actually be speeding you up! 

Invest in observability from Day 1

Similar to IAC, having good observability will help you accelerate your investigations and learn more about your business. In addition to good metrics, you will need to implement tracing to help you debug problems faster. Momento has metrics built in with support for OTEL as well as CloudWatch Dashboards that you can view in your own accounts.  

To learn more about observability and hear from industry experts, check out Daniela Miao’s podcast, Co-Founder of Momento.

Maximize the Benefits of Serverless Applications With Momento

Momento is a truly serverless data platform. With pay-per-use pricing, scale to zero support, ability to handle millions of TPS or millions of users, and hand-tuned clients, it is the fastest way to get your applications to production and instantly scale when your app inevitably gets famous. It even has security best practices covered so your app is not just highly available at any scale, but also the safest experience for your customers.

Try us today!