I’ll save you the “back in the day” dreck, but suffice it to say what got us here will not take us there. Here’s a few observations I’ve noticed.
The first major change is the amount specialization and expertise required. When I started, it was enough to just be a smidge more technical than your salesperson, and the sales folks could get away with being the "dumb sales guy" and rely 100% on the SE s for anything technical. Seems farcical now, but at the time the amount of information that was available online was a fraction of what it is today, so customers were forced to take a call and see a demo to "learn more". Now, 80-90% of product research is done online prior to a company ever even contacting a vendor.
This is is generally good news. When customers get in contact, it's most likely because they've seen something on your company website that struck a chord with a use-case or some pain they're having, which in turn leads to less woody demos. This also means there just aren't that many places to hide for a mediocre SE anymore. The entire sales motion has been shifted in a technical direction, so the SE better have some proper in-depth content and detail to share because the salesperson is going to take care of all the generalist stuff. The prospect has likely seen a full demo on youtube already anyways.
Following this same line the technical barrier for senior positions is much higher. You can still be a SE and do demos, but this is now a Sales Development position (SDE) and you’ll probably be on the marketing team and mostly work trade shows. Any sales rep who’s worth their salt can do a demo overview now and qualify 90% of the deals. SE’s time is now spent doing the tricker stuff like deep-dives with larger audiences, pilot planning, success-criteria definition, scoping, etc. Nothing that wasn’t already in a senior SE’s repertoire, but this is now the focus rather than the outlier.
With this comes a whole new set of skills that are moving from “nice to have” to “required” on a typical SE job rec. What got you hired as a senior SE 10 years ago would not get you hired for the same position now. In cybersecurity specifically, thinking that because you have a C|EH and a business degree will get you hired as a senior SE position right out of the gates is a recipe for disappointment. Unless you already have 5+ years experience I would probably pass on your resume for one of my open positions. I need folks who can write to an API, script in Python, know their way around network infrastructure properly and can rock a mic at a tech talk.
The third major change is the blur between pre and post sales. With technical know-how requirements continuing to increase, it’s only natural a bit is going to bleed over past the P.O. Nearly all software companies have pivoted to a subscription-model where the customer renews every year at 100%. When looked at objectively, it doesn’t take a genius to realize that throughout the lifetime of a customer, nearly ALL the revenue potential lies in post-sales. Once a deal is closed is when the real work starts.
For leaders, the breadth of understanding is more extensive than ever. With all these hyper-technical SEs on your teams, you need to understand what they know and constantly be shuffling folks around where they can make the most impact. I've always said that the best SE teams I've ever been a part of, either IC or coach, have been very diverse crowds. As a leader, you need to foster those skillsets and make sure that talent is being put to the best use.
One of my tactics to help calm nervous testers is to let them know how many friends I have in the post-sales org and that I would never send them a customer where our software wasn’t a fit out of respect. Now however, I sure as hell wouldn’t do it because chances are I’m still going to have to support the roll-out long after the hammer drops. If you're working a territory like most sales teams, you're going to have to re-engage with the post sales folks if there's anything above and beyond a renewal that comes up the following year. If you threw something over the fence and post-sales managed to iron it out, is that customer really going to trust buying from you again? Doubtful...
TL;DR: Technical chops and specialization are the name of the game for SE IC folks, and broad understanding is key for leaders. The industry is getting more difficult, but that also means more job security and more money if you're working for the right org.