Aleksandar Kostadinović je sistem administrator u Registru nacionalnog internet domena (RNIDS). U svojoj dugogodišnjoj karijeri radio je i na poziciji Web Audit Managera u kompaniji ABC Srbija, koja je deo globalne federacije IFABC (International Federation of Audit Bureaux of Circulations). Poseduje čak četiri Microsoft sertifikata: MCSE (Microsoft Certified Systems Engineer), MCP (Microsoft Certified Professional), MCSA (Microsoft Certified Systems Administrator) i MCDBA (Microsoft Certified Database Administrator).