The most important thing: don&#x27;t worry about it.<p>You will probably feel overwhelmed on your first day, probably in your first week too. That&#x27;s normal. It takes time to get used to how the company works, how the codebase is structured, who&#x27;s responsible for what in the organisational structure.<p>If it&#x27;s a good company, there should be someone who you will be able to ask anything you need, no matter how often you need it. I&#x27;ve run multiple projects with perhaps a dozen programmers, and I try to make it very clear to new recruits that they are never bothering me. They don&#x27;t usually believe me at first, but I mean it! Any significant codebase has a huge amount of knowledge and structure known only to its developers, and new guys save so much time if they can just ask a quick question than dig around for themselves. So don&#x27;t be afraid to ask questions incessantly. Definitely form your question sensibly, but don&#x27;t sit around feeling stuck.<p>Honestly, I feel the most important thing you can learn in your first day&#x2F;week is who is the best person to ask about each part of the code that you&#x27;ll be using, and a bit about the general structure of the code. You shouldn&#x27;t expected to produce anything straight away.<p>Also, have fun! I still really enjoy programming after doing it full time for 15 years and hopefully you will too!