Amazon Cognito vs. AWS Lambda

Well Suited

1. B2C mobile and web apps with a high number of users.
2. Cheaper and cost-effective.
3. If the other pieces of the infra are already using AWS services like Lambda, S3, Pinpoint, etc.

Not Suited For:

1. Advanced use-cases (Biometrics based authentication) Email, and other MFA channels.
2. For any use-cases needing SCIM.
3. Customized flows of SSO, and MFA will need a layer on Lambda and other AWS services.

Incentivized

Lambda excels at event-driven, short-lived tasks, such as processing files or building simple APIs. However, it's less ideal for long-running, computationally intensive, or applications that rely on carrying the state between jobs. Cold starts and constant load can easily balloon the costs.

Incentivized

• Strong integration with React.js and client-side applications
• Easy to bridge Cognito identities with the rest of the AWS ecosystem
• Easy to store user profile data directly in Cognito rather than having to build additional services/endpoints
• Easy integration with AWS Lambda to extend and add sophistication to the service

Incentivized

• No provisioning required - we don't have to pay anything upfront
• Serverless deployment - it gets executed only when request comes and we pay only for the time the request is getting executed
• Integrates well with AWS CloudWatch triggers so it is easy to setup scheduled tasks like cron jobs

Incentivized

• Amazon Cognito has a bit of a learning curve. You need to learn its concepts and terminology. The documentation does not describe some topics comprehensively.
• Some Console screens would benefit from improved search and filtering options.
• When another AWS product (e.g., SageMaker) configures Cognito on your behalf, it is not clear what you're getting. For example, the expiration of a temporary password was configured but never communicated.

Incentivized

• Developing test cases for Lambda functions can be difficult. For functions that require some sort of input it can be tough to develop the proper payload and event for a test.
• For the uninitiated, deploying functions with Infrastructure as Code tools can be a challenging undertaking.
• Logging the output of a function feels disjointed from running the function in the console. A tighter integration with operational logging would be appreciated, perhaps being able to view function logs from the Lambda console instead of having to navigate over to CloudWatch.
• Sometimes its difficult to determine the correct permissions needed for Lambda execution from other AWS services.

Incentivized

Amazon Cognito is easy to use and implement if you don't need to implement custom policies. But if your security team requires something outside the box, then implementation becomes complicated and you risk wasting time. There is no option for customizable regex for passwords, which is a major deficiency. The standard password policy, allow to choose the length of the password, if it should contains at least one number, one special character, one uppercase letter and one lowercase letter.

Incentivized

I give it a seven is usability because it's AWS. Their UI's are always clunkier than the competition and their documentation is rather cumbersome. There's SO MUCH to dig through and it's a gamble if you actually end up finding the corresponding info if it will actually help. Like I said before, going to google with a specific problem is likely a better route because AWS is quite ubiquitous and chances are you're not the first to encounter the problem. That being said, using SAM (Serverless application model) and it's SAM Local environment makes running local instances of your Lambdas in dev environments painless and quite fun. Using Nodejs + Lambda + SAM Local + VS Code debugger = AWESOME.

Incentivized

Community support is excellent, many times even better and quicker then the offical AWS support. I really cannot recommend community support enough! Apart from that the service is relativily easy to use and does not have a huge learning curve. Examples are easy to follow and will help you start using the service.

Incentivized

Amazon consistently provides comprehensive and easy-to-parse documentation of all AWS features and services. Most development team members find what they need with a quick internet search of the AWS documentation available online. If you need advanced support, though, you might need to engage an AWS engineer, and that could be an unexpected (or unwelcome) expense.

Incentivized

They are ideal tools to create a secure and unique login experience for our applications. Thanks to its API authorization, Amazon Cognito ensures connections to applications that are secure.It is easy to use and provides easy access to files and applications that you need to complete your goal.

Incentivized

AWS Lambda is good for short running functions, and ideally in response to events within AWS. Google App Engine is a more robust environment which can have complex code running for long periods of time, and across more than one instance of hardware. Google App Engine allows for both front-end and back-end infrastructure, while AWS Lambda is only for small back-end functions

Incentivized

• ROI is great for Amazon Cognito Overall.
• It is included in the AWS Free Tier so you can use it for a good amount without paying, so the software can be tested beforehand.
• The paid pricing is also affordable, so a positive impact on ROI.

Incentivized

• Positive - Only paying for when code is run, unlike virtual machines where you pay always regardless of processing power usage.
• Positive - Scalability and accommodating larger amounts of demand is much cheaper. Instead of scaling up virtual machines and increasing the prices you pay for that, you are just increasing the number of times your lambda function is run.
• Negative - Debugging/troubleshooting, and developing for lambda functions take a bit more time to get used to, and migrating code from virtual machines and normal processes to Lambda functions can take a bit of time.

Incentivized