People want to shop with less plastic, but Zero-Waste shopping asks for containers, planning and time. Convenience wins, and the good intention dies at the supermarket door.
The solution
aPeso connects bulk stores and local markets in one app: order by weight, reuse containers, and pick up without planning your whole week around it.
Timeline
6 months (2023 – 2024, UDIT Master’s project)
The team
Cala Largacha – Product & UX Designer
UDIT Master in UX for Products & Services tutors
Local bulk-store owners and shoppers
aPeso zero-waste bulk shopping app mockupDrop image here
aPeso — key screens.
How might we make Zero-Waste shopping the easy option instead of the committed one?
My master’s project explored why sustainable intentions fail at the moment of purchase, and designed a service that removes the friction rather than the guilt.
🏢 Business problem
Bulk stores are small, scattered and invisible online, so they compete on values against supermarkets that compete on convenience.
👤 User problem
Buying in bulk requires remembering containers, knowing quantities and finding a store that stocks what you need — three failures before you leave home.
Sustainable shopping takes effortBulk buying made convenient
🎯 My role
Sole designer and researcher for the full service, from field research to a tested high-fidelity prototype.
•Field research in markets and bulk stores in Madrid
•Interviews with shoppers who tried and abandoned Zero-Waste habits
•Service blueprint covering ordering, containers and pick-up
•Interaction and UI design for the mobile app
•Usability testing and iteration on the ordering flow
User research
“The barrier is logistics, not belief.”
Everyone interviewed cared about plastic. What stopped them was carrying containers, guessing weights and not knowing which store had what. The problem moved from persuasion to logistics.
aPeso field research boardDrop image here
Journey map
“Intention, planning, store, checkout, repeat.”
The blueprint showed most drop-offs happening before entering the store. Designing the pre-shop moment — stock visibility and container handling — mattered more than the in-store experience.
aPeso service journey mapDrop image here
Product thinking
“Order by weight, not by package.”
Products are chosen in grams with common quantities suggested, so shoppers don’t have to translate recipes into packaging.
aPeso ordering flow diagramDrop image here
“Containers as part of the service.”
A deposit-and-return container model removes the ‘I forgot my jars’ failure entirely and links the app to physical pick-up points.
aPeso container service diagramDrop image here
Design + iterations
“Wireframing the market basket.”
Early flows tested how people shop across several stalls at once. The basket became multi-store with a single pick-up, mirroring how markets actually work.
aPeso wireframesDrop image here
“Warm, market-inspired final UI.”
The final interface borrows from paper labels and market signage: legible, tactile, and far from the clinical look of grocery apps.
aPeso final app designsDrop image here
Outcomes and impact
The tested prototype let participants complete a bulk order in under three minutes and, in interviews, they described it as the first version of Zero-Waste shopping they would actually keep doing.
Personal reflection
aPeso is where I understood service design: the app was only one part. The real design work happened between the store, the container and the person carrying it home.
Want the full walkthrough?
Happy to walk you through the research, the iterations and the final screens in detail.