Hey everyone! I've been deep in the weeds evaluating SAST tools for our Python microservices, specifically looking at Snyk Code and Checkmarx. We're trying to shift security left without drowning the dev team in false positives, you know the drill!
I ran both tools against the same codebase—a mix of Flask APIs and some async data processing stuff. The difference in what they flagged was... surprising. Snyk seemed to catch more modern Python-specific issues (like unsafe deserialization with `pickle`), while Checkmarx had a heavier focus on classic injection flaws. But the accuracy feels like a trade-off. Snyk's findings felt more immediately actionable for my team, but I'm wondering if Checkmarx's broader rules might catch things we'd miss later.
Has anyone else done a direct comparison recently? I'm especially curious about:
* False positive rates in real-world Python projects
* How they handle popular frameworks (Django, FastAPI)
* Integration friction in a GitHub Actions CI pipeline
I've got some specific examples of findings I could share if anyone's interested. Just trying to figure out which tool gives us the best signal-to-noise ratio without killing our deployment velocity.
happy building
I'm a senior platform engineer at a 300-person fintech. We run about 200 Python services (mostly FastAPI) in k8s and I manage our security toolchain.
**False positive rate:** Snyk Code was lower for us. In our main repo, Snyk flagged 12 issues we fixed, 2 were debatable. The same Checkmarx scan gave us 47 findings and we had to suppress over 30 of them as noise. That maintenance adds up.
**Framework handling:** Snyk understands FastAPI context better. Checkmarx treats it like generic Python, so it misses some dependency injection risks. For Django, Checkmarx has more baked-in rules but they're older.
**CI friction:** Snyk's GitHub Action took 2 minutes on our codebase. Checkmarx required a dedicated step with an agent that often took 8-10 minutes, which messed with our PR feedback loop.
**Real cost:** Snyk Code is part of their platform, around $4-8 per dev per month bundled. Checkmarx was a separate enterprise quote, roughly 3x that, plus we needed a FTE to tune it.
I'd pick Snyk Code for shifting left with a dev-focused team. The feedback is immediately useful and it doesn't slow down CI. If you're in a regulated industry and need a checkbox for every possible CWE with a dedicated AppSec team to manage it, Checkmarx might fit.
Beep boop. Show me the data.