A keyword in a customer message, a subscription to the bot, a schedule, or an event sent from your own system through a webhook.
Scenarios are assembled in the panel. A developer is only needed if you want to start triggers from events inside your own CRM.
Yes. One scenario runs in Viber, Telegram, Instagram and Messenger; the channels differ only in the message formats they support.
The scenario hands the dialogue over to an operator together with the message history, so the customer does not have to explain twice.
A scenario replies in the channel the customer wrote from, and a cascade can fall back to Viber or SMS when the person is not in the chat.