Fargate and Lambda: Everything About AWS Serverless

A simple guide to understanding the serverless concept and the difference between Fargate and Lambda in this context.

Are Fargate and Lambda serverless?

Yes, both are serverless services.

But… they don’t mean the same thing, and they aren’t used for the same needs.

1. Definition of “Serverless” (in plain English):

Serverless = you don’t have to manage a server.

You don’t configure a machine, an operating system, or updates. You just focus on your code or your container, and AWS takes care of the rest.

Comparison of the serverless model:

	AWS Lambda	AWS Fargate
Serverless?	Yes	Yes
Do you manage a server?	No	No
What do you deploy?	A function	A Docker container
Automatic scalability?	Yes	Yes
Pay-as-you-go?	Yes (per invocation and duration)	Yes (per second or minute of runtime)
Execution length	Short (up to 15 min max)	Long (hours, days…)
Event-triggered?	Yes (e.g., S3, API Gateway…)	No (it’s an app that runs or listens)
Ideal for?	Small functions, automations	Containerized web apps/APIs

Level of completeness (which one is the most “complete”?)

If you want to know which one lets you do more:

• Fargate is more complete because it lets you run any type of application, as if you had a traditional server (but without having to take care of it).
• Lambda is more limited but ultra simple for running specific tasks.

Clear summary:

You want to…	Use…
Run a function when an event occurs (sending an email, processing an image)	Lambda
Deploy a full API, a Node, Python, etc. backend in a container	Fargate

Concrete Examples

With Lambda (Serverless Functions)

• Send an email when a form is submitted
• Process an image when it’s uploaded
• Back up data when a file changes

With Fargate (Serverless Containers)

• Full website with a database
• Backend API running 24/7
• Continuous data processing service

Benefits of Serverless

1. No Infrastructure Management

• No servers to configure
• No system updates
• No server maintenance

2. Optimized Costs

• Pay only for what you use
• No fixed costs
• Automatic scalability

3. Focus on Code

• Faster development
• Less technical complexity
• More time for features

Best Practices

For Lambda

• Keep functions short
• Optimize execution time
• Handle errors properly

For Fargate

• Optimize container size
• Configure auto-scaling
• Monitor costs

Conclusion

Serverless, whether with Lambda or Fargate, lets you focus on your code rather than on infrastructure. The choice between the two depends on your needs:

• Short, event-driven functions? → Lambda
• A complete, continuously running application? → Fargate

Additional Resources

• AWS Serverless Documentation
• AWS Lambda Documentation
• AWS Fargate Documentation
• AWS Free Tier
• AWS Training