Architecting and administering a hybrid infrastructure running on AWS and leveraging a wide range of their resources & services.Coordinated and performed the migration of the whole infrastructure from bare-metal hosting provider to AWS (my 3rd such migration).Provisioning and configuring distributed stacks with apps written in Python, JavaScript, PHP, Java, etc. and running them directly on VMs, in containers and even as serverless applications.Responsible for introducing and enforcing "The Twelve-Factor App" principles.Worked with the devs in a tight collaboration to apply various semi- and fully-automated processes from the beginning of the app-feature's lifetime:- code analysis- git workflows integrations- app build (env. agnostic)- app deploy (across 4 envs.: local, testing, staging & production)- logging- monitoring (incidents management)That latter allowed to better engineer the reliability of the systems by having a self-healing infrastructure and to integrate easier and faster with external agencies for collaboration purposes.Trained and empowered other departments (ERP, BI and CM) to use Ansible for automating the configuration management and applications' build & deploy (via CI & CD workflows). This brought them to interact with monitoring services and other systems in a self-service fashion.Refactored all Ansible roles and playbooks by following the TDD process and leveraging Docker containers via CI (Jenkins). Unit and integration tests (using the "Golden Master" technique). Because "when your app doesn't have tests, at least your infrastructure does."Enforced the least privileged/deny all security principle and policy in both public-facing and internal systems.Hardened systems (RHEL-based, Debian-based distros) by applying other best practices and standards (patches, thorough monitoring & logging, firewalls, requests throttling, auditing, keys and passwords rotation, etc.), meanwhile integrating with the legacy, VPN-based networks.

Following, there's just an excerpt of some my work at this high paced, agile start-up:DevOps minded System Administrator, introducing and enforcing DevOps best-practices in the IT Dep. as well as 'Documentation as a habit' throughout the company.Responsible for a high-availabilty infrastructure in both a traditional DC and Cloud (Site Reliability Engineering).24/7 On-Call with comprehensive reports, documentation and low Incident MTTR. Setting up procedures and measuring various KPIs for the team, infrastructure and applications effectiveness, strict security policies (both in processes: to the extent of the employees on/off-boarding, infrastructure: starting with the "deny all" and more).Architecting geo-aware, highly available and performant web infrastructures and orchestrating datacenter migrations, disaster recovery solutions and rock-solid security systems.A normal day in the office consists of low-level work with the following self-managed (most of which have been compiled from source + extended/trimmed to achieve the sweet-spot for performance, security and reliability): Varnish, NGINX, Apache, Unicorn, PHP-FPM, MySQL Clusters, Postgres Clusters, MongoDB, Logstash, Elasticsearch, Redis Clusters, Memcached, Graylog2, Nagios, Munin, PagerDuty, NewRelic, Smokeping, Postfix, Xen, Vagrant, iptables, OpenVPN, Bind, distributed file systems.Proficiency-to-advanced knowledge of AWS (2+ years): Route53, CloudFront, S3, VPC, EC2, RDS, ELB, EBS, Redshift, Elasticache, SES, IAM, CloudWatch, CloudTrail and CloudFormation.Collaborating, tracking, chatting, etc., all with the Atlassian stack (both hosted and on-demand solutions).Tool of choice: Ansible - used to do cloud-based configuration management, provisioning, rolling deployments with no downtime and orchestrate DC migrations (essentially what is called Code as Infrastructure). For some projects, used the TDD method.

Administering a fleet of over 30 servers in an extremely demanding environment that pushes data to and fetches it from third parties such as banks, rating providers, payment service providers in a high-standard, fault-tolerant setup. Usually, a normal day would be comprised of monitoring the running systems, planning the new infrastructure in terms of servers, networking, load balancers, deployment mechanisms, monitoring tools; tuning and writing new bash scripts which are a critical part of the whole system.Applications: Guardean, Pentaho, vtiger, MicroStrategyVoIP/PBX: Gemeinschaft‎Programming Languages and scripting: Bash, PerlOS: Debian, Ubuntu, Windows 7Web Platform: Linux (Apache, Nginx, Lighttpd, Tomcat, Java on JBoss)Database: Postgres, MySQLFirewall: iptablesMonitoring: Xymon, Nagios, Munin, M/MonitNetworking: HP switches, OpenVPN tunnels, OpenWrtMail: Exim + ExilogAutomation: PuppetImaging server: FOGRepo management: Apache ArchivaCode Inspection: SonarWiki: ConfluenceTicketing system: JIRADNS: Bind9AV: ClamVirtualization: VMwareBackup: BackupPCRevision control system: SVNDistributed processes: Spread toolkit

• Migrating resources of clients from their previous environments over on our servers• Administering a setup of two DNS servers that provide services for the domains of our clients• Implementing and managing the on-site and off-site backup policies and services for all the servers and workstations• Monitoring the services and servers availability, optimizing and improving their reliability• Administering and implementing firewalls, access lists and security policies that are needed to achieve PCI-DSS compliance.• Hardening the security of the office network environment and of the collocated servers. I managed to achieve the highest level of security needed for PCI-DSS v2.0 compliancy as requested by the level of being a service provider (SAQ-D). Minimizing the scope, deploying new, security-hardened servers, networking rules, ACLs and firewalls• Enforcing and applying security best practices and hacks in order to obtain the highest level of trust for the company’s services and applications (TOTP authentication, password policies)• Redesigning and restructuring the whole servers fleet to obtain a highly redundant, load balanced, extremely scalable clustered environment as well as achieving great reliabilityEnvironment: Programming Languages and scripting: Bash, Perl, PowershellOS: Debian, Ubuntu, Windows Server 2012 (AD, NAS, DHCP, DNS, Exchange, WDS, GPO), Windows XP/7/8, Cisco IOSWeb Platform: Linux (Apache, Perl, Mason, PHP and Postgres)Database: Postgres, MySQLAWS: EC2, VPC, VPN, Multi-AZ RDS, SES, IAM, EBS, CloudWatch, S3Firewall: Shorewall, iptablesMonitoring: Nagios, ZabbixNetworking: Cisco routers and switchesMail: Exchange, Exim, PostfixProxy: SquidDNS: Bind9AV: ClamVirtualization: ProxmoxBackup: Bacula, Mondo Rescue, Duplicity, Windows Server Backup + iSCSI NASHIDS: Samhain + Yule + BeltaneWAF: ModSecurity + OWASP Rule Set + Custom RulesRevision control system: SVN

Day-to-day management of a fully scaled IT Infrastructure in two work points.Always aiming to combine the power of Linux with that of Windows to obtain performance, reliability and security for a modern, hybrid IT infrastructure. While implementing a full-scale DLP system, throughout the company, I carefully adjusted the thin line between empowering productivity and having a paranoid lockdown security.My duties included the negotiation of software acquisition (ERP Software), which I had to calibrate and moderate between the company’s legal department and software provider from a software analyst standpoint, while underlining our requirements and terms.Project Manager and main implementation person for a complete, over 40 HD cameras, surveillance system, biometric access-control, employee clock in system and fully featured, multiple working points-aware ERP system.Designing, deploying and maintaining all the servers (Linux & Win) in the Data Centre of the company (Web Server, Storage, Mail, ERP, Surveillance, DLP) I constantly met with the company’s board in relation to pointing new directions and changes in the IT environment.Environment: 3 engineers, 2 sites, 70 workstations, 9 serversProgramming Languages and scripting: Bash, Perl, Cisco IOS, MS SQL & MySQL, XMLApplications: Charisma & B-Logic ERP, SAGA, Siemens NX & Solid Edge, Dassault Systemes Catia & SolidWorks, progeCAD, Endpoint ProtectorNAS: Win Server 2008, OpenfilerWHM: cPanelWeb Platform: Linux CentOS 5 (LAMP)Active Directory: Windows Server 2008Email: CourierVirtualization: VMware, ProxmoxRemote Access: VNC, SSH, RDPBackup/Restore: Windows Server Backup, WHM Backup & rsync VoIP & PBX: Cisco UC540 & Siemens HiCom 150 OfficeComNetwork: Cisco Smart Switches, Cisco 2911 & RV220W Router, numerous Cisco and other brands APs and switches Security & Firewall: Server-side AV system as well as client-side AV, Cisco ProtectLink, Cisco IOS Zone Based Firewall

Administering up to 3 RHEL 5 dedicated servers, developing Bash and Perl scripts to administer 700+ domains with WordPress instances and other CMSs, optimizing websites for better traction and visibility. Designing and building online shops, communities boards, etc. using PHP frameworks.Responsibilities and duties included:• Choosing the servers technical specifications based on the current load and on the forecasts of the client base• Provisioning the servers with the Red Had Enterprise Linux 5 (later migrated to CentOS 5) and Plesk or cPanel• Hardening the servers security by adding numerous security layers• Designing and implementing a fault-tolerant, on-site & off-site backup system, projecting and simulating the Disaster Recovery Plan (both software & hardware –through advanced RAID configuration)• Helping in maintaining the customer satisfaction level through the support subscriptions and ticketing systems• Creating periodical audits and undergoing assessments based on the firewall logs, resources usage logs, traffic logs, etc. in order to always improve the load balancing, security filters and identify new possible requirements or adjustments.• Offering support 24/7 for numerous incidents, or in case of hacking attempts, suspended services or resources, etc. • Working with third-party developers to constantly improve the satisfaction level of our customers• Constantly researching for the best, cost-efficient and reliable hosting environment. Environment: Programming Languages and scripting: Bash, Perl, HTML, CSS, JavaScript, Ajax, jQuery, SQL, XMLEmail: Qmail, Courier IMAPApplications: Various WAMP web applications and frameworksHosting Control Panel: PleskRemote Access: SSHBackup/Restore: Plesk Backup Manager and rsync based scriptWeb Platform: Linux CentOS 5 (LAMP)Support Ticket System: Redmine, osTicket

This was a position for which I volunteered during my high school studies, as a personal hobby project. Responsibilities and duties included:• Administering the gaming servers (Linux Servers running with AMXX) for the GameLink entertainment division.• Responsibility for the recruitment of new gaming servers administrators• Attendance and facilitating biannual meetups with the purpose of reviewing the proficiency metrics and suggesting new measures to be increasingly competitive as a service provider for our community.• Designing the community’s website and integrating it with the forum that I also installed, configured, maintained and modified according to the needs