Supplied - Building DAC7 compliance tooling from the ground up
DAC7 is a new EU regulation requiring digital platform operators to collect, verify, and report seller data to tax authorities annually, with penalties of up to €1 million for non-compliance.
When Supplied was founded, no tooling existed for this obligation. I joined as the sole designer and led design from zero to one, building the back-office product that takes fragmented seller data and turns it into a valid, submittable DAC7 report. The product now serves 100+ customers and the business raised €1.6M in seed funding.
DAC7 introduced a new compliance obligation that most platform operators were unprepared for. They needed to collect and verify seller data across 22 data points, manage it across fragmented systems, and produce a valid XML file to submit to tax authorities each year. There was no established process and no purpose-built tooling. The deadline was fixed and the penalties for non-compliance were significant.
Starting with a founder-built prototype and no design system or prior research, I shaped the back-office product platform operators use to manage their DAC7 compliance end to end. This covered supplier and seller management, data collection workflows, report building, and a data orchestration layer that takes fragmented seller data and turns it into a DAC7-ready report in a structured, auditable workflow. The output is a valid XML file operators can submit directly to tax authorities.
A few early calls shaped how the product came together.
DAC7 requires specific fields, and users needed to map their own data to those requirements. We considered a straightforward manual mapping interface. Instead, we built AI-assisted mapping, where the system suggests likely matches and users confirm or correct. This reframes the task from configuration to verification.
A second question was how to structure the data linking experience. We considered a single-column flow where users would select fields and see them accumulate in a list. Instead, we designed a two-column layout with sources on the left and the emerging merged dataset on the right. This made the task spatial rather than sequential, so users could see what they were building at the same time as what they were selecting from, without having to hold both in their head at once.
Alongside the product work, I built a design system that gave developers a consistent component library to implement designs and continue adding features independently, without requiring design involvement at every step.
