It is perfectly fine to ask questions during the interview, before the interview, and after the interview. You may ask any reasonable questions about the future job, about the colleagues, about the managers, about the company's culture, rules, policies...
Even though the companies prefer to maintain a monopoly, the interview is actually bidirectional. You are allowed to ask as many questions as needed, to evaluate the company and the job - and they are morally required to truthfully answer those questions. You are totally entitled to reject a company and a job, even if they are willing to have you - if you notice unacceptable red flags.
The reality may occasionally disappoint, of course - but that is life.
If the company / interviewers become uncomfortable when you ask questions, consider that as very red flags. And ask yourself really seriously if you really want to be with them at any costs. Most likely, there will be significant costs, sooner or later.
- before the interview, it is most suitable to ask questions about the interview itself: time, place, tools you need to have (e.g., personal laptop), information you need to have prepared in your mind, and details about the interview itself - including what programming languages would be used.
- after the interview, you might ask questions you forgot to ask during the interview (hopefully not too many), or to discuss the impact of the changes that might have occurred after the interview - e.g., if the start of work can be delayed for XY time for xy reason.