Domain-driven design, although conceived in the early 2000s, was way ahead of its time. We are in the age of solving the most complex problems yet. Given the advancements in technology, there is an expectation to build these solutions a lot faster. While the overall cognitive complexity of the solution is directly proportional to the complexity of the problem, there is a need to effectively manage this complexity. DDD and its principles enable us to achieve this by breaking down complex problems into smaller, manageable parts. In this book, we have made an attempt to distill our experiences and provide a set of concrete techniques to apply DDD in your respective contexts.