Plamen Ratchev has over two decades experience in the software architecture and development field. He has enjoyed building solutions for UNIX, DOS and Windows platforms, with main focus on SQL Server since version 4.21. Plamen is founder of Tangra, specializing in relational database applications analysis, implementation, and tuning. His particular interest is in design patterns, performance and optimization. Plamen has master's degree in computer science with specialization in algorithms and compliers, and holds MCSE, MCSD/.NET, MCDBA, MCSA, MCAD.NET, and MCITP certifications. He is a SQL Server MVP.