SIGNAL London is an upcoming event that will take place on September 19th, with a variety of talks, hands-on learning sessions, and product announcements. The event features speakers from various companies, including Twilio, Transferwise, Google Cloud Platform, and more, covering topics such as Twilio's capabilities, security, machine learning, IoT, social impact, and more. The event aims to provide a platform for developers to learn and network, with a range of activities, including SuperClass hands-on learning sessions and a $bash after-party. Tickets are available now, and attendees can use the promo code PNASH20 to receive 20% off their ticket price.