Public-network-accessible server set 104 and non-public server set 116 include secure communication channel interfaces 112 and 124, respectively. Secure communication channel interfaces 112 and 124 are configured to securely couple public-network-accessible server set 104 and non-public server set 116, enabling secure communications between them, as discussed in greater detail below. Secure communication channel interfaces 112 and 124 communicate data through secure channel 114, which may include one or more communications links, wired and/or wireless, including a local area network, etc. Secure communication channel interfaces 112 and 124 pass encrypted data back and forth between the respective server sets. For example, pubic web app servers 108 of public-network-accessible server set 104 may use secure communication channel interface 112 to transfer private data 136 to non-public server set 116 to persist to storage 122. Likewise, data or web resources required for rendering web pages in public web app servers 108 may be retrieved from non-public server set 116 through secure communication channel interfaces 112 and 124 via secure channel 114.