Interviews, in-person or remote are stressful for you. But it's 100x worse for the interviewee. Stress (and time) makes diamonds but makes most of us perform sub-optimally.
To get an objective and fair view of your candidate, you have to reduce stress during the interview. Making it a pleasurable, learning experience for the candidate regardless of the outcome. It promotes the company's reputation which pays future dividends too.
Go through the candidate's current progress and have some questions about the anomalies, curiosities or interesting things you find in their history. It shows you've taken the time and are interested in them.
Be early (including arriving at the exact time of the interview) and apologize if late with a reason.
Put them at ease by having a casual conversation (location/weather etc) and relate to things they say with anecdotes of your own, being warm where it doesn't hurt to be a little personal too.
Provide an agenda with time boundaries and expectations and indicate that you will leave the last 5 minutes for them to ask questions.
Remind them to relax and worry not about the outcome. Reassure them that it will be a learning experience and to think of it as a conversation between a bunch of nerds.
Take control of the situation and provide specific directions if things don’t work as expected (missing tests, slow connections or errors).
Always provide context with the questions you ask. Ask probing questions to steer them in the right direction without giving them the answer. You want to know if they can think on their feet.
Have affirmative body language when they are saying the right things.
Make it clear to them that they are in control and have the option to change the environment (own IDE or language if applicable) and search for things or even ask you so that they can solve the problem.
Emphasize that they can run their code frequently and fix syntax or logical bugs which won't be counted against them. Ask them and focus on getting to a working solution as a first step.
Walk through scenarios based questions, indicating all components of the problem, explicitly. Example: highlight the application's layers: database<>APIserver(s)<>LoadBalanaver<>client
Genuinely thank them for their time spent so far with take homes tests and interviews etc.
Walk them through the next steps and when they can expect a response allowing the team a generous timeline.
In the event you have to end the interview early because of time or a bad solution, highlight that the 'position' requires a more experienced skill set which deflects blame from themselves. Do remind them to look at it as a learning experience and indicate that you are happy to answer any questions they have about the environment or the company effectively steering them away from the result. If they insist on discovering why the interview is not favorable, list points from your notes and what didn't meet the roll's expectations and what things they should consider working on for future success.