Josef Cacek
Staff Software Engineer Security Researcher at Azul
Brno, South Moravia, Czechia
Summary
🤩
Rockstar🎓
Top SchoolJosef Cacek is a Senior Software Engineer with 14+ years building secure, high-performance backend systems for distributed platforms, currently shaping microservice-based infrastructure at SentinelOne. He specializes in vulnerability intelligence and precision threat detection—at Azul he built an AI-assisted triage pipeline and a bytecode-diff system that maps CVEs to affected Java classes to reduce false positives. A former Hazelcast Security Architect, he owned platform-wide security decisions, implemented LDAP/Kerberos/X.509 authentication, and led CVE lifecycle management and pentesting. Josef is an active open-source maintainer (jd-cli, JSignPdf) and contributor to projects like WildFly and jclouds, bringing practical improvements in Docker, LDAP, and security subsystems. Based in Brno, he blends deep Java expertise with cloud-native tooling (Kubernetes, Docker, Vertex AI) and a habit of turning legacy monoliths into scalable microservice clusters. An often-overlooked strength is his focus on data quality and reproducible pipelines—he pairs engineering rigor with pragmatic security.
14 years of coding experience
24 years of employment as a software developer
Master's degree, Informatics, Master's degree, Informatics at Masaryk University Brno
English, German
Stackoverflow
3,154reputation
215kreached
112answers
0questions
Github Skills (33)
ldap10
authorizations10
docker10
api-design10
testing10
hazelcast10
configuration-management10
authentication10
distributed-systems10
user-authentication10
dockers10
java10
security10
javas10
wildfly10
Programming languages (14)
Github contributions (5)
intoolswetrust/jd-cli
Sep 2013 - Dec 2021
Command line Java Decompiler
Role in this project:
Full-stack Developer
Full-stack DeveloperContributions:9 releases, 3 reviews, 93 commits in 8 years 4 months
Contributions summary:Josef implemented native libraries and integrated them into the Java decompiler, improving its functionality. They added control over the decompiler's behavior through system properties, enhancing configurability. Furthermore, the user refactored the code to improve performance and added new features such as STD_IN class reading for more flexibility.
jnajardecompileropenjdkjava
hazelcast/hazelcast
Apr 2016 - Jan 2023
Hazelcast is a unified real-time data platform combining stream processing with a fast data store, allowing customers to act instantly on data-in-motion for real-time insights.
Role in this project:Back-end Developer
Back-end DeveloperContributions:575 reviews, 422 commits, 842 PRs in 6 years 9 months
Contributions summary:Josef's contributions focused on adding or modifying features related to the Hazelcast configuration, specifically within the context of Java code. They added a `toString()` method to several configuration classes, which improves debugging. They also implemented improvements to the code related to managing the protocol version. Furthermore, they enhanced the project's functionality by preventing division by zero in operations.
computationstream-processingbigtablereal-timestreaming-data
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