The embassy in Singapore is highly efficient. One of the form that I submitted to NVC has an error. During the interview, I was told to correct it, upload, and then email to notify the embassy it's uploaded. My interview was Tuesday morning. I upload the correct form around noon and emailed the embassy. Three hours later I got the reply that they would process my case. Wednesday is national holiday in Singapore. The online visa status was changed to "Issued" Thursday afternoon, and I received an email Friday morning that my passport is ready to pick up. Super fast.