Zoho’s instant messaging app Arattai witnessed a 100x jump in traffic in the past three days, co-founder Sridhar Vembu said on Monday in a post on X. The new sign-ups crossed 350,000 from 3,000 a day. The Chennai-headquartered software firm intends to add more infrastructure to the Arattai app, which is seen as a potential homegrown peer to WhatsApp. “We are adding infrastructure on an emergency …