We specifically hired a "support engineer" and got lucky finding an excellent person for the role. She understands how software works so can debug strange thin

We specifically hired a "support engineer" and got lucky finding an excellent person for the role. She understands how software works so can debug strange things without needing developers to get involved, but is also extremely patient and understanding with people that just don't know how to use our tools or have technical issues from clients. Prior to her being here we had a rotating developer system going. That had an upside of forcing developers to learn odd parts of the system they hadn't seen before, but mostly frustrated people since developers didn't like doing that sort of work. We had also tried the Slack bot system, but nobody wants some automated answer or queue when they have a sales call in an hour and need some reports fixed up now. People just learned to skip that and ask developers directly, which was frustrating, but also probably the right decision given the scenario and available options. Some things aren't high priority and our support engineer uses a ticket system to keep things sane, but is still always available as a real person first. Having a real person can cost more than some automated system but in our experience, has been well worth it. TLDR: Pay for quality.