<p>UCB is a pharmaceutical company working in neurology and immunology, whose stated ambition is to change the lives of people living with severe disease. Buzzworks built four frontend applications for iOS and web, between 2017 and 2020, that UCB uses to run and follow up clinical studies, applications that fit together as one set. The four are: eDiary, a patient smartphone app for recording daily activities, medication and questionnaires, designed so that filling it in takes as little effort as possible while the data behind it stays protected and correctly attributed; Investigator Portal, where a clinician reviews patient data, with access scoped so that a doctor only sees the patients they are authorised for; Site PRO, a tablet application used during a site visit to complete additional questionnaires, where the input has to hold even in the rush of a consultation; and Study Admin Webapp, the overarching application for managing patients, sites, clinicians and the access rights that determine who can see what across a study. Two requirements shaped the work: privacy, meaning patient data protected at every step with access strictly limited to those entitled to it, and data integrity, meaning every entry recorded accurately, attributed correctly and reliable enough to base clinical decisions on. Both sat in the architecture rather than in an audit just before go-live. Integrity was implemented through audit traceability, so that what a patient entered was exactly what a clinician saw later, and through defining a questionnaire once so that it behaved identically on phone, tablet and portal, giving a single source of truth instead of three interpretations of it. The project was run as genuine co-creation: Buzzworks developers worked in one team with UCB's stakeholder and product owner, UCB's project and domain experts and the quality assurance team, taking decisions on scope, behaviour and trade-offs together in the same room on a two-weekly cadence across the full three years of the engagement, so that questions about access rules, data handling or a regulatory requirement were resolved inside the team rather than through ticket exchanges. In the delivered set, patients record their day without spending long on it, clinicians get a clear view of what happens between two visits limited to the patients in their care, and the study team manages access and follow-up from one place. Because UCB's product owner and domain experts were embedded in the build, the reasoning behind every privacy and data decision stayed inside the team, so anyone changing something later does not have to work out first why it is the way it is. Buzzworks is based in Belgium and works internationally.</p>