Twilio

Twilio provides programmable building blocks that let software send and receive communications. Developers call its APIs to send text messages, place and route phone calls, or reach customers on WhatsApp, and pay according to usage. Twilio Verify sends one-time codes to confirm a user's identity, Twilio SendGrid delivers transactional and marketing email, and Twilio Conversations manages multi-channel message threads. On top of these sit two larger products: Twilio Flex, a contact center that companies customise in code, and Twilio Segment, a customer data platform that collects events and routes them to other tools. It is used by engineering and product teams, from startups to large companies, for notifications, authentication and customer support.