Tal Sabadia

Administered hundreds of production Linux servers, mainly RHEL, supporting university applications and core services; evaluated AlmaLinux and Rocky Linux in test environments after the CentOS changes.

Managed F5 BIG-IP LTM across multiple partitions, including pools, virtual servers, monitors, iRules, HA, troubleshooting, and vendor-assisted upgrades.

Wrote F5 CLI helpers to recreate and manage application services during network migrations, reducing repetitive work and making cutovers more consistent.

Moved Linux and F5 services into protected networks behind Palo Alto firewalls. Prepared IP ranges and DNS TTLs, validated policies and service paths, staged cutovers, and checked traffic afterward with little to no noticeable user impact.

Designed Redis Sentinel HA for Moodle with six Redis instances per server; failover was seamless to users and improved performance and resilience.

Upgraded and maintained Zabbix, changed templates, wrote custom Linux checks, supported Grafana-Zabbix, and used Kibana during investigations.

Resolved email-authentication and legacy-system compatibility issues across Postfix, Cisco IronPort, SMTP, SPF, DKIM, DMARC, and DNS; coordinated with the Microsoft 365 and Google Workspace owners.

Built Bash and Python tools for backups, Zabbix checks, Postfix message handling, and F5 operations. Used teammate-built AWX workflows for provisioning and contributed operational requirements.

Set up a new Moodle exam environment in OCI ahead of launch and supported selected Azure-hosted servers.

Built and led a systems team of up to three engineers, interviewing and training two team members while staying hands-on with delivery, troubleshooting, and escalations.

Managed production Linux, web, and email infrastructure and handled customer incidents across operating systems, application services, DNS, and network protocols.

Improved performance and reliability in hosted environments through focused troubleshooting, better monitoring, and targeted configuration changes.

Designed custom infrastructure solutions, including a VPN service that rotated IP addresses automatically from defined triggers.

Managed Linux and Windows servers for customer web, email, and hosting services.

Expanded monitoring and alerts so service issues were visible earlier.

Troubleshot server, application, DNS, and network incidents in a customer-facing hosting environment.

Troubleshot Linux, routing, DNS, firewall, VPN, GRE, NAT, and load-balancing issues using monitoring, reachability tests, traceroute/MTR, interface state, and routing context.

Automated firewall and gateway setup, tunnel and VPN provisioning, access restrictions, monitoring integration, and reachability checks.

Correlated alerts, tunnel state, endpoint relationships, timing, and recovery behavior to separate host failures from wider path or provider issues.

Prepared new IP ranges and DNS TTLs, validated required firewall policies and service paths, coordinated staged cutovers, and verified traffic after migration.

Migrated Linux servers and F5 services into protected networks behind Palo Alto firewalls; prepared IP ranges and DNS TTLs, validated service paths, and staged the cutover.

Verified traffic afterward and finished with little to no noticeable user impact.

Designed and implemented Redis Sentinel HA for Moodle with six Redis instances per server.

Delivered seamless failover for users and improved performance and resilience.

Built a separate LISTSERV delivery path with dedicated Postfix gateway and relay tiers.

Kept promotional traffic away from primary mailing lists, reducing complaint and blocklisting risk for the main mail path.

Built a Zabbix environment with custom templates, triggers, alerts, checks, and Telegram notifications.

Used Ansible and CIQ Ascender for repeatable provisioning, configuration, and maintenance across independently managed servers.

Migrated selected core systems from CentOS 7 to RHEL 8/9; mapped application and dependency compatibility, rebuilt servers, and staged validation and cutovers.

Resolved migration issues while maintaining service continuity.