If nothing else, it's a useful tool when doing reviews with your manager, or when you're trying to evaluate your personal growth.
It comes in really handy when you're interviewing or looking for a new job.
Julia Evans calls it a "brag doc": https://jvns.ca/blog/brag-documents/
It doesn't have to be super detailed either. I tell people to write 50% about what the work was, and 50% about what the purpose/value of the work was.. That tends to be a good mix of details and context.
Writing in it once a month, or once a sprint, is enough. Even if it's just a paragraph or two..
dude maintained a "me wall" of achievements, commendation medals, etc. plus a file full of other crap. he mentioned he got a lot of promotions because you have a section to fill out where you describe all the shit you did over the least year, and he always came with examples...
Honestly, putting those details in writing in a way that I retrain after leaving might leave me vulnerable to claims of violating my corporate NDA. But legalities aside, yes, it would help with these kinds of interview issues - prospectively only of course, not retrospectively.
Annoyingly, it's also exactly the kind of doc that's difficult for people with ADHD to create and maintain rigorously, even though people with ADHD are more likely than average to need the reminders of those details. A lot of ADHD problems are that kind of frustrating catch-22, especially when interacting with a world that is largely designed around more typical brain types.
If I can ask a follow-up question: Is it the act of writing it down, or the whole recall aspect of it that is challenging? Or something else?
I've personally starting using audio transcription with a voice recorder to capture ideas more easily when I'm not at my computer (I hate typing on my phone keyboard) and that has made building these kinds of diary/log/notes documents a lot easier because I can just speak my ideas into the recorder whenever it is convenient for me, instead of waiting until I'm at a computer.
I would definitely not expect someone out of work for a while to have any meaningful side projects. I mean, if they do, that's cool, but I bet the sheer stress of not having a job kills a lot of creativity and productivity. Haven't been there, so I can only imagine.
For such a candidate, I'd probably want to offer them a time limited freelance gig rather quickly, so I can just see what they work like. For people who are already in a job, it's more important to ensure fit before they quit there, but your scenario opens the door to not putting that much pressure on the interview process.
Beyond immigration types of obstacles, somehow recruiters and hiring managers rarely consider how many bad managers, bad executives, and bad companies there are when evaluating gaps and short tenures in an employee's resume. But equally, discussing those matters during an interview risks being seen as unprofessional and unreasonably negative. "Why did you leave this company?" "Oh, the warnings I got about the leadership from a former employee before I joined turned out to be true, and they didn't want to hear professionally presented necessary feedback about emotional safety in an emergency incident response situation, so they fired me without a single meaningful 1:1 discussion other than trying to assign blame." / "Oh, the CEO was enough of a problem that the investors eventually replaced him in a subsequent funding round despite him being the majority shareholder, but that was long after I had resigned or been fired due to that CEO's particular problems." / "Oh, they communicated in a very idiosyncratic way which didn't work for me and which I haven't seen at any company before or since." / etc. Most of that doesn't fly in an interview, but equally, even if it did, saying too much of that sounds like making up excuses for oneself even when it's 100% true. Same thing for why a job search doesn't succeed quickly.
Ours is a messy and imperfect industry, and it sucks that interview candidates have to pretend otherwise to seem like they'll be reasonable employees. Meanwhile the companies and executives that act in those ways get to present whatever positive and successful image they want, and they get to praise each other for firing fast or cutting costs with attrition or layoffs.
One of the problems I see in big corporates is that feedback cycles for bad policy can be so long, whoever caused something is far away when the effects hit. AKA nobody really cares. But to be fair, I've always tried to care, and worked with many others who do.
Especially people with ADHD don’t remember details as long as others, even though ADHD does not make someone a bad hire in this industry (and many successful tech workers have it).
I do prefer take-home challenges to live coding interviews right now, or at least a not-rushed live coding interview with some approximate advance warning of what to expect. That gives me time to refresh my rust (no programming language pun intended) or ramp up on whichever technologies are necessary for the challenge, and then to complete the challenge well even if taking more time than someone who is currently fresh with the perfectly matched skills might need. I want the ability to show what I can do on the job after onboarding, not what I can do while struggling with long-term unemployment, immigration, financial, and family health concerns. (My fault for marrying a foreigner and trying to legally bring her into the US, apparently.)
And, no, my life circumstances do not make it easy for me to follow the common suggestion of ramping up in my “spare time” without the pressures of a job or a specific interview task. That’s completely different from when I can do on the job or for a specific interview’s technical challenge.