Formal (not freelancing), full-time (not as a client value-add in an IT role) development? More than a decade.
After school (non-traditional college grad)? A few months after getting an IT degree I no longer had any interest in using (but got just to show that I knew what I already knew for SysAdmin jobs I was no longer looking for upon graduation), and a month before I began my second degree program (this time for development, and again just to prove I knew what I already knew, just as useless as the first).
I advise neither the shotgun nor the sniper approach to applying. Get yourself a nice kitted-out AR-15 instead. You want both accuracy and capacity; taking not a few, but rather several, well-placed shots.
What do I mean by this?
Set up catch-all templates for both your resume and your cover letter, but apply with variations on the latter at the very least.
a. Your resume shouldn't change much. You're just adding skills and experience (and/or education/certs). When you add, chances are you'll want every company you apply to to see it. Only tailor it if there are things in your skills section obviously irrelevant to that particular role.
b. You cover letter needs to be personalized, or else it's pointless; not just to the job description, but based on your own research of the company, its stated vision/mission, and any opportunities you may have identified in said research (Stack Overflow Careers makes this easy by pre-populating the cover letter you filled in from your last application).
Your application is unique, though you may still be able to form a text template based on recurring questions you encounter (no matter how stupid they may be, e.g. "In 150 characters or less, tell us what makes you a great fit").
Think long and hard about what a company reveals about its culture by making the application needlessly difficult. This includes those who ask you to upload a resume and then still expect you to manually fill your employment/education/certs, those who try to exploit "Quick Apply" (for greater reach) but then hide "Send an email to blah@blah.blah to apply" to filter out those who actually use the mechanism, or those who expect you to record a one-way video interview (because they can't be bothered to give you their time, while expecting you to give yours). Such behaviors are red flags about what it's like to work for them, and your time is better spent on other potential employers.
"Real projects" need not be huge. I love it when applicants create utilities. Maybe it's an ESLint config, or some nifty little CLI tool, or a shell script to provision a fresh Mac or Linux install. If they're useful, give them repos and link to them on your portfolio site (note to self, both GitHub and portfolio are ridiculously out of date).
(adding to the gun metaphor, defend those you care about): Don't ever waste your time on someone who demands your references upfront (most likely a staffing agency). You depend on these people, they're doing you a favor, and you need to protect them from overexposure (which they will get if you submit them for preemptive reference checks).
Formal (not freelancing), full-time (not as a client value-add in an IT role) development? More than a decade.
After school (non-traditional college grad)? A few months after getting an IT degree I no longer had any interest in using (but got just to show that I knew what I already knew for SysAdmin jobs I was no longer looking for upon graduation), and a month before I began my second degree program (this time for development, and again just to prove I knew what I already knew, just as useless as the first).
I advise neither the shotgun nor the sniper approach to applying. Get yourself a nice kitted-out AR-15 instead. You want both accuracy and capacity; taking not a few, but rather several, well-placed shots.
What do I mean by this?
I submit that an AK would be better than an AR, and the trigger should be on single shot (maybe burst, at a push). Never full auto.
The most important part, is the gunmanship. Are you standing right? Are you holding it right? Are you breathing correctly between shots? Etc.
But I think the gun metaphor still holds up in both our cases.