Alex Dafnis
Verified Expert in Engineering
Cybersecurity Developer
Zielona Gora, Poland
Toptal member since February 27, 2026
Alex is a dedicated cybersecurity professional specializing in B2B security services for startups and Fortune 500 enterprise environments. His core focus is on incident response, threat hunting, risk reduction, compliance, and driving security operations center (SOC) maturity. Alex has extensive experience operating within global 24/7 SOCs and delivering multi-client operations, frequently managing security for more than 20 clients simultaneously.
Portfolio
Experience
- Security Monitoring - 5 years
- Cybersecurity Operations - 4 years
- Cyber Threat Hunting - 3 years
- Incident Response - 3 years
- Splunk - 3 years
- SOC Analyst - 3 years
- Data Loss Prevention (DLP) - 3 years
- FortiSIEM - 3 years
Preferred Environment
Linux, Splunk, Microsoft Sentinel, FortiSIEM, FortiSOAR, FortiEDR, FortiAnalyser, ISO 27001, NIST, General Data Protection Regulation (GDPR)
The most amazing...
...achievement has been optimizing alert triage across over 20 clients, reducing false positives by 85% and escalating threats in under 20 minutes 91% of the time.
Work Experience
Security Operations Center (SOC) and Network Operations Center (NOC) Analyst
Freelance Clients
- Monitored combined dashboards for over 30 clients, acting as the first line of defense for security alerts and network performance availability.
- Assisted in tuning security information and event management (SIEM) alert thresholds to reduce background noise, helping senior analysts focus on critical events.
- Contributed to a 15% reduction in the daily incident volume by identifying and whitelisting repetitive false positives.
- Documented standard operating procedures (SOPs) for routine alert triage and client communication.
Security Support Specialist
Freelance Client
- Assisted with the deployment of data loss prevention (DLP) agents to workstations to prevent unauthorized data transfer.
- Performed periodic user access reviews to ensure adherence to the principle of least privilege (PoLP) for sensitive financial folders.
- Conducted periodic user access reviews for sensitive financial directories to meet PCI-DSS and ISO 27001 access control requirements.
- Identified and remediated more than 50 unencrypted endpoints, bringing the fleet into full compliance with General Data Protection Regulation (GDPR) and California Consumer Privacy Act (CCPA) data privacy standards.
SOC Analyst
Freelance Client
- Performed real-time monitoring of security queues, specifically looking for indicators of compromise (IoCs) related to network traffic.
- Escalated validated threats with detailed triage notes and packet capture evidence.
- Analyzed phishing emails reported by employees and blocked malicious sender domains in the email gateway.
- Participated in shift handovers to ensure continuity of monitoring for high-priority banking assets.
Experience
Enterprise SOC Lab Deployment
Certifications
Certified Ethical Hacker (CEH)
EC-Council
NIST SP 800-53B
NIST
NIST SP 800-53A
NIST
SIEM Engineer
LetsDefend
Blue Teal Level 1 (BTL1)
Security Blue Team
Incident Responder
LetsDefend
Malware Analysis
LetsDefend
SOC Analyst Certification
LetsDefend
Project Management
Vellum Global Educational Services SA
Network Defense
EC-Council
Splunk Core Certified User
Splunk
Cybersecurity Specialization
Cybersecurity Analyst
IBM
Skills
Tools
Splunk, Wireshark, Microsoft Intune, Nagios
Languages
Bash, Python
Paradigms
Penetration Testing
Platforms
Linux
Storage
ClickHouse
Other
FortiSIEM, Security Monitoring, Incident Response, Cybersecurity Operations, SOC Analyst, SOC 2, Cyber Threat Hunting, Microsoft Sentinel, FortiSOAR, FortiEDR, FortiAnalyser, ISO 27001, NIST, General Data Protection Regulation (GDPR), FortiGate, fortiEDR, Data Loss Prevention (DLP), PCI/PA-DSS, MITRE ATT&CK, Microsoft Defender XDR, Cybersecurity Consulting, Enterprise Cybersecurity, Splunk Enterprise Security, Network Security, IT Project Management, Malware Analysis, SIEM engineer, SOAR Engineer, NIST SP 800-53A, NIST SP 800-53B, IT Security
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