@batjko @sudshekhar The validations include, validating client details against government databases, verify computation of front end again by calculating the same here with our own computation block. Check for data integrity of the user in some 3rd party vendor API etc and I need all that to be well under 10 seconds.

And, you are right, database access, read times and other parameters you mentioned are of paramount importance. So with all that in mind, I had Scala/Go/Java in my mind, but still wanted to se if there is any other framework which will be factory fit for such requirements.

Well, out of those validations, the database checks are in all likelihood going to be your primary bottlenecks. Reducing the cost of making those calls, e.g. by using caches, is going to be vital.

The cost of your computationally heavy validations may not be particularly high, since you only expect around 30 requests per minute, i.e. 1 every two seconds on average. Go is faster than Java or Java-derived languages, but any of the languages will do fine for you, performance-wise.

As I said above, your language choice here won't affect your performance much, but may be more around other requirements, incl. the ecosystem for libraries, ease of the learning curve or available expertise etc.