As a product owner, your job is to make assumptions, or hypotheses. (Hypothesis-driven product discovery, anyone?) You assume that your priorities will be the best outcome, the shortest time to market or something else. But how good are your assumption when it comes to reality? Did that sale increase occur and was it thanks to your great mind or just pure luck? Do people around you understand and help you with your assumptions? Impact mapping is a lightweight tool that helps you with quantifying and communicating your assumptions.
Continuous discovery means an open backlog where everything is considered speculation and hypothesis. Continuous validation means that the user experience is validated for each release, rather than up front. This may sound like big budget to you, but let me give you a case study, about how a single team accomplished it on a tight budget.
A small team with a small budget has the advantage of not losing its head with big ideas from experts in different fields, be it architecture or user experience. The budget constraint sharpens your effort in a way that could be healthy even to a larger team.
Do you, a developer, have a feeling that the user stories your product owner is but a list of ideas prioritized on gut feeling only? That the relationship between them and their purpose are vague? Impact Mapping is an agile conversational tool by Gojko Adzic that may be primarily for product owners but hey, a developer needs a purpose too!