Symfony (at least 2 years exp in this framework specifically), preferably exp in Symfony in versions 4-6 but some combinations like ver 2/3 and then version 5/6 is also OK
rest API - both integrating with external APIs as well as creating their own, JWT/OAuth2 authentication mechanisms
Docker/Vagrant/Ubuntu - good exp in using at least one of them
good knowledge of MySQL and/or PostgreSQL
good OOP practices and practical knowledge in using design patterns (ex. MVC, Dependency Injection, factories, adapters, singletons and more)
Nice to haves:
exp in working with cache, ex. Redis, Memcache, ElasticSearch, Varnish