From a mainstream perspective, there are mixed mode ICs that contain a bunch of analog components (op amps, comparators, etc.) and allow you to configure them digitally. E.g. the whole PSoC series from Cypress (formerly, now Cypress is part of Siemens).

Slightly less mainstream, there is the concept of FPAA (field programmable analog array), which is the equivalent of an FPGA but for analog instead of digital.

E.g. see https://www.anadigm.com/fpaa.asp.