During one of our recent implementations, CRM Bitrix24 was used as a backend for another external system - for a student's account. Through an account interface, students can apply for training in the chosen course, upload the necessary documents, monitor the status of their application, pay tuition bills, and also interact with their curators. All this is very deeply integrated with Bitrix24 business processes. For such a deep integration of Bitrix with a third-party system, we lacked standard REST methods - the logic for using requests became too complicated and confusing.
AWS, Python, Dynamo DB, MongoDB, Serverless, NoSQL, AWS Lambda, Bitrix24, PHP, SQL, MySQL