The website is hosted on AWS. We are using elasticache service of AWS for storing the session information. Need opencart to use the Redis server of elasticache for storing php sessions. I have tried it myself but could not do it. So the developer should integrate and demostrate that it works..
You can see some directions on how to do it here.. [login to view URL]
Its very easy job if you have done before. Also you need to document one page which includes the information about the settings modified or files installed. You will have ssh access only and no ftp and hence need to work via command line only. Happy bidding.