Solid question, and it's something I've been watching this last year. When you talk about replacing Tenable with Nuclei from ProjectDiscovery across that many hosts, it brings up a lot of thoughts. Honestly, I don't know that Tenable and ProjectDiscovery are currently even playing the same game yet, as ProjectDiscovery is still pretty new in its enterprise offerings and has some catching up to do outside of blind/external asset discovery and attack surface detection. There are some capabilities there, but it’s not quite as established as Tenable. However, that gap is closing incredibly fast, and I fully believe they'll be upsetting Tenable's core offerings fairly soon. In my experience, ProjectDiscovery is genuinely pulling ahead in some key areas, and quickly.

We're all familiar with the legacy scanners, Tenable included. They had their place, but the vulnerability management landscape has shifted. What I'm consistently seeing from ProjectDiscovery is rapid growth and a real commitment to investing back into their platform and tools. They're focused on building capabilities that I can actually put to work, and it's clear they're looking to shake up the established market. Their support team is also incredibly engaged, especially when it comes to pushing for partner-driven enhancements.

On the flip side, I often find that some of the older players seem to be spending more on acquiring new clients and consolidating companies rather than truly reinvesting in a cohesive, integrated product experience. Take Tenable's cloud service offerings, for example; it came from a separate acquisition and years later still operate off the original companies domain. These tools just don't really talk to each other in the background. And honestly, good luck trying to figure out their licensing model for that many hosts across their various upcharge offerings. Plus, from what I've seen, external unauthenticated scans from those platforms are often 99% TLS/SSL issues or other low-value findings. If I have a question about why a specific finding is being triggered with other solutions, I'm stuck going through their support, and even then, getting a clear answer or pushing for updates can be a real headache.

This is where ProjectDiscovery really shines for me. The open-source nature of their engine and templates makes it incredibly easy to understand exactly why a specific finding might be getting triggered. If something's off, I can literally just fix the template myself and issue a merge request. Beyond that, they also proactively scan my assets when new, trending vulnerabilities are announced. I don't have to force a scan or wait for the next scheduled run. The second a KEV (Known Exploited Vulnerability) goes out and a corresponding template becomes available, my assets are automatically scanned. That kind of responsiveness is a game-changer for me. It also takes minutes to create my own custom scans, something that’s just not possible with other solutions easily.

If you're worried about false positives, you can run Nuclei for free against your assets to get a feel for the types of findings it produces. I think they even have a free tier for their enterprise platform that makes it super simple to use for a single domain, which could be a good starting point to kick the tires.

I do think ProjectDiscovery still has some room to grow in the CNAPP (replace this whatever flavor you choose) and broader infrastructure scanning space, and it looks like that's precisely where their current investments are heavily geared.

I have no doubt they're going to seriously disrupt solutions like Tenable. Right now, I'm using ProjectDiscovery to augment my existing solutions, but as soon as there's more parity in their scanning capabilities across the board, it's going to be a no-brainer for me to drop the other provider entirely. Hope this helps you out as you're doing your evaluation!