The syncs are declarative, not imperative. They don't map 1:1 to API calls by design. You tell us what you want the destination to look like, and we figure out how :). Kinda like how a database creates the best plan for your SQL query before executing it.
Here's an example - https://i.imgur.com/05T5iKK.png. This sync maps your users table to Salesforce "Contacts" and the mapping interface also encodes the foreign key relationship between Contact:Account in Salesforce. Under the hood, we do all the lookups, caching, batch API calls using the bulk API, automatically handle rate limits, and only send changes from your database.
This is one of our key design differences compared to iPaaS tools like Tray, Zapier, Workato, Mulesoft, etc., which tend to just map actions to API calls 1:1. Data integration being declarative is something I'm really passionate about personally... wrote a blog with more examples at https://hightouch.io/blog/the-future-of-data-integration-wha...