This post was written by Philip Miller, CISO at H&R Block, and published by Rein.
I’ve spent more than two decades in application security.
In that time, I’ve seen wave after wave of “innovation” promise to fix AppSec- new tools, new platforms, new acronyms. And yet, despite all of it, the core problem hasn’t gone away. In many ways, we’ve made it worse.
Today, we’re in the middle of another massive disruption. AI is connecting everything in new ways, and the temptation is strong to chase the next shiny object. But I’ve learned that this is exactly when discipline matters most.
In times of dramatic change, fundamentals are always your safe spot.
For application security, the fundamental isn’t better dashboards, posture scores, or incremental improvements to the network. The fundamental is creating more secure applications. And too much of AppSec has drifted away from that goal, adding layers of tooling that dress up the problem instead of solving it.
The industry has also developed a habit of chasing what’s easy instead of what matters. It’s far simpler to deliver a five or ten percent improvement than to take on the eighty percent problem head-on. But real security doesn’t come from stacking partial solutions on top of each other. It comes from solving the biggest risks at their source.
That’s why Rein caught my attention.
Rein is the only AppSec solution I’ve seen that provides a true backstop inside custom code. It sits directly in the line of every application call. That architectural decision changes everything. Instead of guessing, sampling, or proxying, Rein operates in the reality of production- where risk actually exists.
Because of that, it doesn’t just add visibility or improve hygiene. It actively stops real threats, shows exactly what happened, and pinpoints the precise line of code involved. It’s the same leap forward we saw when security moved from antivirus to EDR: from “something bad might have happened” to “this was happening, and we stopped it.”
Restoring confidence in appsec.
Just as importantly, Rein restores something AppSec has been missing for a long time: confidence. It gives confidence back to both AppSec and AppDev.
AppSec teams can finally prioritize what’s actively risky, knowing there’s protection in place while fixes are being worked on. Developers know they’re being asked to fix issues that genuinely matter- not another long list of theoretical findings. That shift alone has the potential to repair a relationship that’s been strained for years.
I don’t say this lightly: this is the first AppSec solution in 20 years that I’ve been genuinely excited about. Not because it’s flashy, but because it’s focused. Rein doesn’t chase symptoms. It tackles the root of the problem- and that’s exactly what AppSec has needed all along.
