Its not about what the employee wants, its about what the employer wants. You negotiate AFTER the company is interested, not before. If it doesn't interest you don't apply. Leave the big dick, fuck you, what can you do for me attitude at home. You're not a rockstar so don't act like it. And if it's tech you're definitely not a rock star or a ninja or anything else.

Be able to speak to everything on your resume, don't put it on there if you can't, ie AI resumes.

Go over the job requirements, know where you've already done xyz.

There is usually a chance to ask interviewers questions at the end, have a few handy like is this a new role or replacing somebody, why did they leave, how is success measured etc...NOT what are the perks, what is the pay, do you have ping pong tables?

If you know who the interviewer is go on Linkedin and scout them out. Scouting the company is good too but know more people post complaints online than compliments so glassdoor is going to skew negative.

I could go on but you get the idea.