Configuration and management of over 100 Linux servers that runing services software: Apache,Nginx,Varnish DDoS protection and Security Java Tomcat,Jetty Qmail,Postfix,Zimbra Oracle database(DataGuard,RAC..),Mysql FTP,SSH Server Samba,LDAP,BIND Firewall, Proxy and caching server Advance shell scripting Distribute filesystem(DRDB,GlusterFS..) Media transcoding,LiveStreaming(rtp,rtmp,hls..) Media streaming system CDN system Coding html,css