Send a follow-up when it adds value
A follow-up is usually most useful when you want to thank the interviewer, reinforce a genuine point of fit, or send something you promised during the discussion.
It is less useful when it becomes a way to chase too early or to repeat your whole application in email form.
Keep the note short and specific
A few lines are enough. Thank them for their time, mention one point from the interview that confirmed your interest, and close politely.
The strongest follow-ups feel grounded in the actual conversation rather than copied from a template.
Know when to wait
If an employer gave you a timescale, respect it. If that date passes, then a gentle check-in is reasonable.
Repeated chasing rarely improves the outcome. One thoughtful follow-up is stronger than several anxious ones.