Hey everyone! 👋 New member here, super excited to join this community. I've been diving into the world of data pipelines and analytics engineering, and I keep hearing about Semgrep for code security in CI/CD.
My team is starting to talk about implementing static application security testing (SAST), and Semgrep is a top contender. Everyone loves the idea of catching vulnerabilities early, but I'm hearing some whispers from the devs about a big concern: **slowdowns during the merge process.**
From my data analytics mindset, I'm thinking about this like a pipeline. If you add a heavy validation step, it can bottleneck the whole flow. So I'm really curious about real-world experiences.
Could anyone share their setup or walk me through how you integrated Semgrep without causing merge delays? Specifically:
- What does your typical scan time look like? (e.g., for a medium-sized microservice)
- Do you run it on every PR, or on a different schedule?
- Have you tweaked rulesets to be more focused?
- Any tips on configuring it to be "fast feedback" vs. "deep scan"?
I'm hoping to gather some best practices to bring back to my team. The goal is better security without adding frustration or significant wait times for developers trying to merge their features. Thanks in advance for your insights!
It can slow things down if you treat it as a single gate. The key is segmentation.
We run a targeted rule set on every PR, only scanning the changed files. That takes under 30 seconds. The full repo scan runs nightly on the main branch. Trying to run the entire rule set on every merge is where you create the bottleneck.
You need to separate the "fast feedback" rules for critical issues from the "code style" or informational ones. Start with a small, high-impact ruleset for the PR check and expand the nightly scan.
Segmentation just moves the bottleneck. Your "targeted rule set" on changed files? It's still a gate. Now devs wait 30 seconds instead of three minutes, but it's still synchronous feedback they have to wait for.
And scanning changed files only gives you a false sense of security. The vulnerability is in the integration, not the diff. Good luck catching that with your nightly scan after the code's already merged.
You're just trading one slowdown for another.
If it ain't broke, don't 'upgrade' it.
You've got a point about the synchronous gate still being there. But 30 seconds versus 3 minutes is a huge difference in developer flow - it's the difference between a coffee break and a quick glance.
The vulnerability in the integration argument is valid, but it's why you combine the fast PR check with the nightly full scan. The trade-off is catching a large class of obvious, high-risk issues immediately, while the broader integration risks are flagged and rolled back the next morning. It's not perfect, but it's a practical pipeline. Isn't the goal to balance safety with velocity, not achieve perfect security?