The absolutely low hangingest fruit, highest ROI activity I recommend every candidate do as they're gearing up for a job search is to meticulously go through their past work history month by month or even week by week and dredge up the memories of all the things they've actually done leading up to this point in their career and then find another person and do the physical act of explaining each of the things so they know if they can even tell the story in a way that makes sense or not.

The reason I believe it's the highest ROI activity is because I keep on suggesting it to people and most people think it's a great idea and then they don't do it. It's gotten to the point where, for the people I really care about, I have to schedule a 3 hour block with them on a weekend and sit down with them just to actually have them do it and after it happens, everyone agrees the result is transformative but people have a weirdly high activation friction to actually doing this.

It should get to the point where I can quiz you on a "tell me of an example where you X" and they should be able to rapid fire answer back to me what example they would pick and we can do a round of 30 of these in 10 minutes. If they find themselves having an esprit de l'escalier moment of wishing they had picked different examples, that's a sign they should go back and revise more.

I have so many friends who have done so many awesome things in their career but then freeze up in the interview and just plain forget to mention the perfect relevant anecdote and they think it's some defect on them but, surprise, all of our recall is terrible and we all constantly forget details of things that happened years ago and the only way to get good is with discipline and practice.

Another technique I encourage every candidate to master is the classic politician technique of transforming every question into the question you wished the interviewer had asked in a seamless enough way that they don't notice. eg: One of my close friends who I coached was absolutely terrible at hypothetical scenarios, she would totally freeze up because that's not how her brain worked. I trained her so that whenever an interviewer asked:

"How would you design this theoretical feature for this made up example"

Her templated reply would go something along the lines of:

"Oh yeah, we faced quite a similar problem when I was working on [...] at [...]. The way I approached it was [...] because [...] and it meant that [...] for [...] stakeholders. So I guess in this scenario, I would apply those same techniques [...] to make sure that [...] met [...]'s requirements.

At the end of the day, we're generally all in denial about how much interviews come down to vibes and how vibes is a very trainable skill that it's very possible to reduce the error rate through practice (note: this is different from presenting a different vibe from how you actually are IRL which I generally advise people is long term counter productive). Engineers especially have a lot of emotion invested in how interviews "should" be that isn't at all concordant with any version of reality and they have hangups about investing skillpoints in things that empirically improve their interview performance because it goes against their mental model of what should improve their interview performance.