Istanbul, Istanbul, Türkiye
Managing and leading enterprise network & security operations, including design, configuration, troubleshooting, patching, and lifecycle management of critical infrastructure components such as switches, routers, firewalls, VPN gateways, IDS/IPS systems, and wireless access points across multi-vendor environments (Juniper, Fortinet, Palo Alto, Check Point, Cisco, HPE, Dell, Arista). Responsible for end-to-end network and security service availability, operational stability, and continuous improvement of infrastructure systems. Leading operations involving: Layer 2 / Layer 3 network design, routing, switching, and troubleshooting IP-based network protocols and enterprise connectivity solutions Network performance, capacity, and availability management Enterprise backup and configuration management strategies Overseeing and supporting enterprise infrastructure platforms: SIEM environments (Splunk) for log management, monitoring, and incident correlation Monitoring platforms (Nagios) for system, network, and application availability Web filtering infrastructure (McAfee Web Gateway / TMG) Linux server environments including patching, hardening, and troubleshooting Windows, Linux, and macOS administration, including Active Directory, Exchange, drivers, printers, and system-level troubleshooting Driving security and compliance initiatives: Infrastructure hardening aligned with security standards and best practices MFA integration into VPN infrastructure (Duo Security) Secure access and identity validation enhancements Managing physical and hybrid infrastructure components: CCTV and storage systems (Milestone, QNAP) in alignment with security and compliance requirements Supporting enterprise infrastructure services: DNS, DHCP, SMTP, FTP, TFTP, SSH, SFTP SNMP-based monitoring systems (PRTG, Cacti, MRTG, Opmanager, Zabbix ) Additional responsibilities: Incident management, root cause analysis, and advanced troubleshooting across network, application, and hardware layers Technical documentation and architecture diagrams using Microsoft Visio Cross-team coordination and stakeholder communication Ensuring high availability, resilience, and operational continuity of IT services Strong analytical thinking, problem-solving capability, and communication skills with a focus on maintaining secure, stable, and scalable enterprise infrastructure environments.
Experienced Network & Security Team Lead with a strong background in enterprise infrastructure, data center operations, and mission-critical network security environments. I lead and contribute to the design, implementation, and operation of complex network and security infrastructures across production environments, ensuring high availability, resilience, and secure service delivery. My experience spans across: Enterprise network design and operations (L2/L3, routing & switching) Security infrastructure (next-generation firewalls, policy management, segmentation) Load balancing & application delivery (Citrix ADC / F5 environments) DDoS protection and controlled testing scenarios Data center migration and transformation projects Change management (CAP / CAB processes) in high-risk environments Incident and problem management in production-critical systems Vendor and third-party coordination for infrastructure operations I have been actively involved in large-scale infrastructure transformation initiatives, including data center migration projects and high-impact operational changes where service continuity and risk management are critical. Beyond technical execution, I take ownership of operational stability, cross-team coordination, and ensuring that changes are delivered with minimal business impact in highly sensitive environments. Currently focused on strengthening my expertise in network automation, cloud networking, and security architecture, while progressing towards broader infrastructure leadership and architecture-oriented roles.
As part of my current role, I am entrusted with the responsibility of diligently monitoring all network devices and servers utilizing professional tools such as Grafana and OpManager network monitoring systems. This encompassing monitoring effort includes tracking critical metrics such as bandwidth utilization, uptime, downtime, CPU usage, memory usage, and disk usage on network devices. Furthermore, I meticulously observe CPU usage, memory usage, and disk usage on the server-side. Additionally, I ensure the effective monitoring of essential services on specific servers. At Paycore, our team assumes full accountability for managing the comprehensive network and security operations. This encompasses proficiently overseeing Checkpoint Firewalls, Palo Alto Firewalls, Fortigate Firewalls, Juniper Firewalls, Cisco Firewalls, and associated network devices. Moreover, I expertly administer and leverage the capabilities of Citrix and F5 load balancers for efficient load balancing. To further enhance my professional expertise, I am actively engaged in acquiring knowledge and skills pertaining to IBM QRadar, which serves as our security information and event management platform. Furthermore, I am entrusted with the on-premises management of Radware DDoS devices, ensuring their optimal functionality and bolstering the overall security posture. By diligently fulfilling these responsibilities, I play a pivotal role in fortifying the network and security infrastructure at Paycore, thereby upholding peak performance, unwavering reliability, and resilience against potential threats.
During my tenure as Director of Splunk SIEM for a period of 4.5 years, I was responsible for overseeing all operations related to Splunk and the associated servers. The Splunk environment primarily operated on CentOS versions 6.0-6.5. Upon completion of this role, I successfully transitioned the management of Splunk SIEM to the EMEA SOC Team. Currently, my responsibilities encompass the management of Splunk Network and Security logs. On the Linux side, I adeptly managed two CentOS 7.5 servers and one Debian 9.0 server. Additionally, I took charge of various servers, including Nagios Server, DHCP server, and new Splunk servers deployed on these systems. Furthermore, I proficiently administered numerous embedded Linux servers, such as Mcafee web proxy servers, Qnap servers, and Synology servers. In terms of monitoring, I implemented comprehensive network monitoring using PRTG and Nagios. This involved the monitoring of network devices and servers, encompassing aspects such as bandwidth utilization, uptime, downtime, CPU usage, memory usage, and disk usage. Critical services on select servers were also subject to monitoring. Throughout my tenure, I single-handedly managed the entire network and security operations at Teleperformance in Turkey. This included the administration of Checkpoint Firewalls, Fortigate Firewalls, Juniper Firewalls, Cisco Firewalls and Network devices, as well as the Pulse Secure SSL VPN device and IP Camera system. Additionally, I assumed responsibility for managing FortiManager, FortiAnalyzer, and FortiAuthentication specifically for the Fortigate firewall. Overall, my professional experience entails a comprehensive scope of responsibilities and successful management of diverse systems, ensuring the smooth operation of network and security infrastructure.
In my professional role, I served as a technical support specialist, providing assistance to end-users and small to mid-sized companies in resolving their computer-related issues. Through my expertise and in-depth knowledge, I effectively addressed a diverse range of technical challenges faced by clients, ensuring the smooth operation of their computer systems.