Nodejs Website Deployment on Beanstalk

Hello.

If you are considering production operation and are unsure of the amount of load that will occur, why not choose an M-based instance type?
M-type instance types are highly versatile, so I think you should start with an M-type instance type first and then change to another instance type depending on the load etc.
https://aws.amazon.com/ec2/instance-types/?nc1=h_ls

If the load is small or medium-sized and there is almost no load, I think the T-type instance type is fine.
However, with T-series instance types, once the CPU burst credits are consumed, the performance will drop to the baseline throughput, which may affect application operation in some cases.
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/burstable-credits-baseline-concepts.html

RDS also has M-based instance types.
https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/Concepts.DBInstanceClass.html