Ask HN: How to overcome fear of the unknown when applying to jobs
I'm looking at applying elsewhere and I have ambitions to move to one of the larger tech companies. I applied to one of the major startup fin-tech companies in the UK not too long ago, interview process went pretty well, got to stage 5/6 and did very well in technical discussions (discussed messaging systems, transaction integrity with multiple approaches etc), however fell short in the programming task (a program heavily focused on a certain aspect of programming, something I didn't have a massive amount of experience with so got tripped up when trying to convey the intricate details of what exactly the program was doing, though it was completely functional).
Since then, I've improved massively in that part of my skill set, however it has left me with a feeling/fear that I could apply to another company and face the same problem of getting tripped up by a single thing where my knowledge isn't up to scratch, despite my pretty abundant knowledge in other areas. Is this something commonly experienced and if so what can remedy it?