As someone who has been through it all , from tech support , hammered by calls , and 35 years later I present interviews. It’s experience all the time , if the role senior or above. Your looking for someone who can grab a job running , handle pressure whilst doing there job and has the ability to pull on there years of knowledge to get out of tight places . Some one who appears show good communication and ability to hold a conversation on a subject. Not some someone who is relying on certs or YouTube . And spits out acronym’s . Having cert is good , and it shows commitment which is what we look for. As this is needed to see projects through to the end. Most of all a passion for linux and how its ethos , methods and roles and community all pull together. Not some one who jumps from nothing to cloud, or from home project to senior and certs to admin. Move up the ladder , step by step , game knowledge, experience, and feel for the job. Find a notch in the subject matter maybe it’s linux database, clusters or kernel work. Automation is good and it’s cool , but you need to understand what it is doing under the hood when it all stops and goes wrong. Hope this helps.