Welcome to Q&A and thanks for posting your query here.
First I would suggest you to make sure that the "Always On" option (available in configuration blade) is turned on so that cold starts are avoided. Please note that, this is applicable only for function apps running on dedicated app service plan and elastic premium sku.
Concurrency and batching is where performance can be improved from Functions platform perspective. It is upto you configure the number of messages that needs to be processed in a batch and you can have upto 16 concurrent sessions under the sessionhandler options. We can add sessionhandleroptions under the host.json file
"sessionHandlerOptions": {
"autoComplete": false,
"messageWaitTimeout": "00:00:30",
"maxAutoRenewDuration": "00:55:00",
"maxConcurrentSessions": 16
}
Host.json reference : https://learn.microsoft.com/en-us/azure/azure-functions/functions-bindings-service-bus#hostjson-settings
Please try this configuration and let me know the outcome.
I hope this helps!
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