First of all, give an explanation about what happened. Asking for the candidates feedback about the technical issues he/she went through and work on this with the proper team. And make sure this will be fixed. Offer the candidate alternatives to get interviewed. If he/she is really interested in the company, I would expect an empathetic attitude and willingness to move forward with the process. Being in the same mood (comprehension, empathy, looking for solutions) will give us a lot of lights about each other.

To keep the candidate engaged, I would promptly acknowledge the technical issue, apologize for the inconvenience, and reassure them that we value their time and effort. I’d offer to reschedule the interview at their earliest convenience while ensuring a smoother process next time. In the meantime, I would keep them engaged by sharing company updates, exciting projects, or insights into the team and culture to maintain their interest and enthusiasm about the opportunity. This demonstrates professionalism and care for the candidate's experience.

Acknowledge the technical issues. And then offer to reschedule the interview for the job seeker. So that they aren't thrown off and anxious because of the issues. If they are okay. Apologise again and move forward.

-Instant communication with the candidate to state the issue and offer reschedule options at their convenience. - Make sure to offer alternative channels to resume the interview in case the technical issue may reoccur

Br prompt. First and foremost give a call to candidates and apologize for the inconvenience caused. Then proceed by rescheduling as per candidates availability. Meanwhile try to resolve the issue as soon as possible to ensure the importance of everyone's time.