Instructor since 2023
Jonas Lindqvist
Application security engineer helping developers write, review and test secure code
Sample
- Students
- 7,320
- Courses
- 4
- Instructor rating
- 4.3
- Reviews
- 28
About Jonas
I sit between development and security teams, reviewing code, tuning scanners and teaching developers how common vulnerabilities actually appear in real code bases.
My courses are written for developers first. We read vulnerable code, exploit it in a safe lab, fix it and add a test or rule so it stays fixed. Examples use Python, JavaScript and Java because that is what most teams I meet write.
I focus on the OWASP Top 10, API security, authentication, and tooling such as Semgrep, CodeQL and secret scanners. My aim is that security becomes part of your normal review, not a separate step at the end.
Courses by Jonas
What students say
Elif D.
Sample CVSS 4.0 finally makes sense
Scoring the lab findings and justifying each rating in a sentence was very practical.
Leo B.
Sample Review routine improved our pull requests
The routine and comment examples made our developers far more confident reviewing security relevant changes.
Ryo T.
Sample Code review checklist is great
The checklist from the last lesson is now part of our pull request template.
Daniel W.
Sample Webhook verification done right
Signature, timestamp, idempotency and fast response. Exactly the checklist I needed.
Yusuf K.
Sample Reporting section is gold
Rewriting weak findings into strong ones was eye opening. Our developers now actually read the reports.
Moritz A.
Sample Custom Semgrep rules finally make sense
Writing taint rules for our own request wrapper removed most of our false positives in a week.
Silvia G.
Sample BOLA explained with real code
Resolving access through the caller in the query itself changed how we write every handler.
Laura V.
Sample Finally practical OWASP training
Every category ends with a pattern and a test. Our team added access control negative tests the next sprint.