115thAirhacksQ&A.md

115thAirhacksQ&A.md

Ask questions and see you at October 2nd, 8 pm CET: youtube.com/c/bienadam

Also checkout recent episode:

Please keep the questions as short and as concise as only possible. Feel free to ask several, shorter questions. I will also cover some questions in my "shorts" youtube.com/@bienadam/shorts between the shows.

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New: the airhacks.tv discord server: discord.gg/airhacks

Hello @bytesarray,

Please don't use double for my bank account.
Actually, if you're working on Forex stuff, BigDecimal is enough. You only need to multiply as currency rates are one-way only. EUR to USD is not the inverse of USD to EUR.

Also, if you're printing on the web, the Intl.NumberFormat does a great job at printing currencies.

Hello @AdamBien,

I have two questions :

1. I was wondering how you manage your authentication and authorization. How do you get your end user in your controllers or how do you check its permissions ?
   With Spring Security, the SecurityContext can get you an Authentication which is roughly no better than an Object because you have to know the implementation to get anything out of it. There are some not so well-known conventions but no strict API therefore it is often pure chaos.
   Is it any better with Jakarta or microprofiles ?

2. Java 21 is now released (yay !) and Virtual Threads are soon (if not already) there with the LTS flag.
   Do you foresee any gain when using virtual threads for APIs using JPA ? As the database connection pool is limited, will virtual threads still help ?

Hello again,

Do you know any good zero-configuration formatting tool for java code out there ?

I'm tired of both debates over spaces, tabs, import order... and PRs full of formatting changes for just 3 lines of actual business line of code.

A tool like Prettier from the javascript world would be nice (and even there I have to fight so they do not put any configuration).

I watched your session about Fat Lambdas. As I understood you can run entire Quarkus microservice as one lambda. I understand that it's better to use Dynamo in AWS, but if we have to use Postgres, how we can replace connection pooling in Quarkus application with RDS Proxy or something else?

Hello Adam.
What do you think about Jakarta Data specification? How can we use it with BCE?

Thank you.

Hi Adam!
What do you think about using database ids on the REST API? I am trying to keep them out of my domain models as I consider them an implementation detail. Instead I try to use business keys. In case you do the same, how do you handle composite keys on the REST API?

Another question on identifiers: When I need to generate an identifier and I cannot use a database sequence (e. g. because I am on a client), then one option is using UUID. Now a colleague pointed me to ULID. What do you think about UUID vs. ULID, do you use it in your projects?

On AWS, when to use DocumentDB vs. DynamoDB vs. AuroraV2? What are your criteria for picking one of them because it seems that many developers are defaulting to relational database systems.

On AWS, when to use SQS vs. SNS vs. Kinesis? I have a use case where I need to notify a client application about data changes and I have different clients that are not allowed to see each others notifications. Would EventBridge also be an option to send events to client applications?

HI Adam

Is it possible to use S3 bucket as source from CodeBuild which has a VPC access. By default codebuild was working perfectly with S3, then I add codebuild to VPC and connection to S3 stop working. I added NAT gateway and I manage to get access back. Can I avoid NAT somehow - to reduce costs. Maybe use VPC endpoints are the solution?