Flexible General Automation. Competes with Workato but feels a bit more modern/flexible.
Tray is another heavy hitter in the "General Automation" space. It sits between Make and Workato. It is extremely flexible and can handle very complex logic branches. It is often used by SaaS companies to build integrations for their own customers (Embedded IPaaS).
A strong contender for the mid-market, but most will prefer Make for the price.
Medium difficulty. Easier than writing code, harder than Zapier.