The rise of big data and smart sensing, with the promise of more educated and informed decisions, has fuelled a shift towards more data-driven decision-making in local and national government. However, we are observing a disconnect between the people who are affected by these decisions and their access to tools and resources to collect data in order to provide the needed evidence for change. To truly democratise this process and for citizens to become active prosumers of data, new mechanisms of citizen data production are needed. In this paper we report on a two-year ethnographic and iterative co-design process with the local community. This work encompassed the design, development and deployment of SenseMyStreet (SeMS), a bespoke sensor commissioning toolkit that enables citizens and community groups to use and commission a city's scientific-grade environmental monitors, determining where they will be located on their streets and collecting data to evidence hyper-local issues. Unlike prior research, which creates alternative data sources to contest city data, our toolkit helps integrate citizen commissioned data into the city datasets used by citizens and decision-makers. Reflecting on the design process and evaluating the ways people engaged with the digital tools of the toolkit, we highlight how commissioning can be configured to promote equity in the smart city, empower citizens to take ownership of issues and facilitate the creation of community networks that utilise the data for local benefit.

In this paper, we present a socio-technical process designed to engage children in an ongoing urban design project-Streets for People-in Newcastle, UK. We translated urban design proposals developed by residents and the local authority to enable children to contribute ideas to the project. Our process comprised three stages: situated explorations and evidence gathering through digitally supported neighbourhood walks; issue mapping and peer-to-peer discussions using an online engagement platform; and face-to-face dialogue between children, residents, and the local authority through a 'Town Hall' event. We report insights gained through our engagement and show how our activities facilitated issue advocacy and the development of children's capacities, but also surfaced tensions around the agency of children in political processes. We reflect on the challenges of working in this space, and discuss wider implications for technology design and ethical questions that 'scaling up' such work might pose.