Network Security Engineer / Architect (NDR)

Our client is a global technology and professional services company with a Cyber Center in Prague. The team serves enterprise clients across multiple industries and operates as a mature, production-grade security operation — not a lab, not a pilot. The Prague team is around 270 professionals. The security operations unit has ~80 people, including roughly 27 engineers who own the technical layer — SIEM platforms, detection pipelines, incident response tooling. English is the language of client-facing work; Czech is day-to-day inside the team. Why This Role Exists Now: The security operations team is expanding. Two new engineers are joining — this is one of two roles being filled at the same time. The other role goes deeper on cloud SIEM (separate ad). The team has experienced engineers who know the detection architecture well, and now is a good moment to join — the knowledge transfer opportunity is real and accessible from day one. If you've been in an MSSP environment where detection ownership stays with the vendor or a central content team — this role is built differently. Most MSSP setups give you the SIEM. This one gives you the rules.What Matters Most: We're not looking for someone who ticked every checkbox on a certification list. Three things actually matter: — SIEM hands-on time — you've worked with Splunk (SPL queries, correlation searches) or Microsoft Sentinel (KQL, analytics rules) for at least 2 years in a production environment — Linux system knowledge — you understand how logs are generated, how syslog works, what endpoint telemetry looks like — Detection thinking — you can write a correlation rule from scratch, explain why it's tuned the way it is, and recognize when a low-severity alert is worth investigating English needs to be solid for reading technical documentation and writing client-facing reports. If your background is primarily QRadar or ArcSight — that's a valid starting point. We care more about your engineering instincts than the vendor logo. Nice to Have: — Experience with Chronicle/Google SecOps — YARA-L rules, UDM data model — Familiarity with QRadar or ArcSight from client or previous employer environments — Security certifications: GCIA, CEH, CompTIA Security+, Microsoft SC-200, or Splunk Core Certified — Scripting for automation — Python, PowerShell, or bash for log parsing or playbook triggers Don't let the nice-to-haves stop you. If you have the three core things, the rest can be learned.Role / Mission: Your job is to keep the SIEM infrastructure healthy and make sure the detections it runs actually catch things worth catching. Day-to-day: monitoring and triaging alerts, maintaining log source pipelines, tuning correlation rules, and working with analysts when something escalates. You'll also write and maintain playbooks so the team doesn't reinvent the wheel during incidents. Tech context: the team runs Splunk and Microsoft Sentinel as primary platforms. QRadar and ArcSight in the mix from legacy clients. Chronicle/Google SecOps is present in some environments — knowledge there is a plus. Success in 12 months: you own your detection playbooks, you've added at least one meaningful improvement to the ingestion or detection layer, and when someone has a question about platform behavior, they come to you first. Key Responsibilities: — Monitor, triage, and investigate alerts across SIEM platforms (primarily Splunk and Microsoft Sentinel) — Build, tune, and maintain detection rules and correlation logic — SPL, KQL, or both — Maintain SIEM infrastructure: log sources, ingestion pipelines, platform health, onboarding new data feeds — Write and update incident response playbooks; support L1/L2 analysts during active investigations — Participate in on-call rotation; contribute to post-incident documentation and lessons learned What This Role Is NOT: — Not a pure L1 analyst position — you're here to engineer and improve, not just watch dashboards — Not a client-facing sales or advisory role — this is delivery, inside the engine room — Not a solo build-from-scratch project — you're joining an existing team with live infrastructure Operating Model: Standard working hours, no shift work. On-call is a shared rotation across the engineering team. Hybrid setup in Prague or fully remote is also possible. Reports to: Head of Security Engineering. English for client documentation; Czech for internal team communication. Travel is minimal.Interested? Let's Talk If this sounds like your kind of challenge, apply now — let's build something great together. Throughout the process, you'll be guided by a senior recruiter with hands-on IT experience. Straightforward, technically grounded, without unnecessary recruitment overhead. Send your CV or LinkedIn profile to or reach out via linkedin.com/in/jirisoljak Interview process: — Intro call with SITEQ recruiter — 30 minutes, we'll explain the role and client context — First interview with the team lead — get to know each other, talk about the team and day-to-day — Technical interview with a senior engineer from the security operations team — hands-on discussion, no trick questions — Offer Please note: this position is open only to candidates eligible to work in the EU without visa sponsorship, able to reside and work in the Czech Republic.

Leading international technology company specializing in the development and operation of payment systems. They rank among the most significant global providers of payment solutions — their technology and services are used daily by millions of customers and businesses across continents. The company continuously invests in innovation, including blockchain and digital currency technologies, ensuring secure and reliable real-time transaction processing. The Prague team manages core systems handling payment authorization and processing. This role is focused primarily on security perimeter and application delivery layer (CheckPoint & F5) within mission-critical infrastructure across Europe and the U.S.• Minimum 4+ years of experience in Network / Security engineering • Strong hands-on experience with CheckPoint firewalls • Strong hands-on experience with F5 BIG-IP LTM • Solid understanding of TCP/IP, routing, VPN, NAT, and security best practices • Experience troubleshooting across L3–L7 layers • Solid Linux administration skills • Familiarity with network monitoring and management tools • Communicative English; proficiency in Czech or Slovak required Nice to have: • CheckPoint or F5 certifications • Experience in high-availability enterprise environments • Experience with hybrid or cloud-integrated infrastructureAs part of the Network & Security team, you will take ownership primarily of firewall and load balancing technologies across enterprise data center and production environments. Your key responsibilities: • Administration and optimization of CheckPoint firewalls (R80+) – policy management, VPN, IPS, threat prevention, clustering • Management of F5 BIG-IP (LTM) – load balancing, SSL offloading, traffic management, HA configuration • Advanced troubleshooting across L3–L7 layers in production environments • Implementation of security segmentation and performance optimization measures • Monitoring and incident response, including participation in a weekly on-call rotation • Cooperation with the Security team on upgrades, migrations, and vulnerability remediation • Preparation of documentation and audit reports related to infrastructure compliance • Continuous improvement of network reliability, performance, and resilience Cisco routing/switching remains part of the environment, but the primary focus of this role is security and application delivery infrastructure, not general network operations. You will collaborate daily with colleagues from Europe and the U.S.Interested? Apply now and speak with a senior IT recruiter who understands both the technology and the people behind it. Please note: This position is open only to candidates eligible to work in the EU without visa sponsorship, residing in the Czech Republic long-term, with proficiency in Czech or Slovak.