Introduction

The age of intelligent machines has arrived, and conversational interfaces are leading the charge. Over the past couple of years, we have been swarmed by a number of new kinds of machines and software collectively known as bots. Bots are automated hardware or software machines that are powered by the advances in Artificial Intelligence (AI) technologies. Recent developments in machine learning algorithms, such as deep learning and deep reinforcement learning, have improved the performance of AI tasks such as Automatic Speech Recognition (ASR), Natural Language Understanding (NLU), Text to Speech Synthesis (TTS), and Image Recognition. This has accelerated humankind's journey toward the technological singularity, the point in time when AI surpasses natural human intelligence by leaps and bounds.

One of the long-term goals in the field of AI is to build computer systems that can have human-like conversations with users. With recent advances in AI technologies, we are now one step closer to achieving this goal. Now, it is no longer fictional that we are able to interact with devices and gadgets in our homes and offices using nothing but voice. We still have a long way to go toward creating standards and building digital beings that are capable of seamless natural language conversation. However, a recent surge in interests and massive investments in pursuing these ideas suggest that we are on track toward evolving such a global standard. If you are excited about the recent developments in AI and automation technologies, this book is for you. We will embark on a journey toward a point in time in the future that the design guru Mark Curtis calls conversational singularity, when conversational devices disappear and conversation between man and machine is seamless and natural.

This is a book for programmers beginning to build conversational interfaces. Today, basic button-based chatbots can be built without even having to write a single line of code. In this book, that is where we will start. We will gradually move toward more complex and flexible architectures, and we will explore channels to use, such as Facebook Messenger, SMS, and Twitter. We will also be exploring tools for understanding natural language and conversation management as we proceed. Finally, we will end our journey by building voice-enabled bots on platforms such as Amazon Alexa and Google Assistant.