Infosys’ Chennai development centre today celebrated its 20th anniversary. From the centre’s first steps in a two-floored office with 300 plus employees, the Bengaluru-based IT company expanded to sprawling campuses at Mahindra World City and Sholinganallur and increased employee strength to over 20,000. Chennai centre embarked on global sustainability practices. Some of its key initiatives include Building Management System for better monitoring and control of heating, ventilation and air conditioning, smart water metering and focused efforts in renewable energy, the release said.