2025
https://medium.com/@AlexanderObregon/how-spring-boot-implements-feign-clients-for-rest-apis-8a4108fa248c
    https://habr.com/ru/companies/otus/articles/909336/
2023
https://reflectoring.io/create-openfeign-http-client/
https://habr.com/ru/post/719934/
https://habr.com/ru/post/717610/