Thank everyone for the reply. Regarding the KSUUID, understood. For the serverless part, lamda is limited to 15 minutes, that is right. But what do you think about the following design? 1. Have a bunch of lambda functions each corresponds to a certain event. 2. No data is stored in memory all go to Dynamo DB. 3. On the event triggered from FreeSWITCH Lamda queries the Dynamo DB for the config and related call data. 4. Lambda does processing and sends the commands to FreeSWITCH 5. Lambda updates the Dynamo DB. In case you agree that the above design might work, what do you think about the tech stack to use? I was thinking about python switchio ( https://github.com/friends-of-freeswitch/switchio), but 1) In the case of using serverless there is no need to use the async approach from the ESL engine 2) I am not sure it is developed anymore Maybe vanilla python ESL will work fine in this case. Please advise. Best regards, Nikolay Zaytsev