WhatsApp.<p>NEVER use whatsapp for work communication. it blurs you personal and work life, there's no boundaries, you are online 24/7, it drains you energy, chats are completely ephemeral (if 30h have passed since a message its gone forever), no pins, no task tracking, no onboarding, no search, no automation, it starts to fall apart with half a dozen people, insecure if they steal your phone, dumb ui, no scheduling, no nothing. Work and personal life must be separated, one app for each. work done? CTRL+W slack and done, offline mode, in whatsapp you cannot close it and its very unprofessional. Your boss hits u up at saturday 9pm and you will have that chat
unread lingering there and draining your energy till monday, constant context switch between work and personal. It's horrible.<p>If you are a startup founder, DO NOT use whatsapp for work comms.