What's your top tip for doing well at interview?

My overarching advice would be to go in prepared and just be yourself. Do background reading on Phoenix and be prepared for competency based interview questions (ie. can you give me an example when you have demonstrated x,y,z). Think of the likely questions you may be asked given the role you're applying for, such as juggling multiple priorities, managing differing stakeholder views, etc. Think of examples where you've done this and you'll often find you can use the same core few examples for a range of questions. It doesn't have to be from the same sector either, for example, you could say when I worked in a cafe we were short staffed and so I managed customer facing activity with equally important back of house tasks such as ordering supplies, helping with potwash, etc as an example of juggling priorities. Finally be yourself as you're more likely to come across as genuine and relaxed.