Designing grocery substitution
Product Design · Just Eat
I led the end-to-end design of the Grocery Substitution feature, overseeing stakeholder management, research, copywriting, design operations, and QA as part of the agile development cycle. Through this project, I helped the business save €1,234,552 with a 95.71% adoption rate.
Role and Impact
Platform.
iOS/Android app,
Team.
Sole Designer (Lead Designer), 6 Product Managers,
1 Researcher, 1 UX Writer, 33 Engineers
€9,227,866 lost
Problem
Just Eat expanded into grocery with the vision of ‘Empowering everyday convenience’.
However, 1/5 groceries are either missing or out of stock which costs the business €9,227,866 in compensation.
⬇️ Reduce the compensation costs
by building a grocery substitution feature
Objective
Saved €1,234,552
compensation cost
Impact
This new feature reduced compensation costs by 13.38.% with a 95.71% adoption rate across all markets. It lets users quickly set grocery substitution preference for all items in the basket, while also offering flexibility for an individual item without interrupting the order flow.
“I don’t want to feel like
I’m shopping again”
Users
From previous research, I found that too many substitution decisions before ordering create cognitive load, feel unnecessary for customers., and potentially risk impacting conversions, as it reduces the perceived speed and convenience of fast groceries.
How might we make grocery substitutions easier and faster?
Hypothesis
We believe that enabling users to set a single global substitution preference for all items in the basket, with an option to change the preference for individual items, will help users receive their grocery substitutions without friction or frustration, therefore, increase the order completion rate.
Pro: Users can focus more on the actual item list without substitution creating too much noise.
Con: Substitution preference options are hidden one layer down in the bottom sheet.
Option A: Bottomsheet
Exploration
Option B: Buttons at item level
Pro: Users can easily access the substitution preference at both the basket and item level.
Con: Too many item-level buttons upfront can increase cognitive load.
Option A was clearer to users
User research
Through 2 user research sessions, option A was understood better by users due to its clarity. It also aligned with the business direction, as product team will be adding more substitution options such as contacting the customer in the future. Based on research insights, I refined and iterated the design for the final developer hand off.
Substitution
by default
Final solution
When users enter the basket after adding groceries, they can see if any items are unavailable, and they will be substituted by default. This creates a faster and easier grocery ordering experience for users and improves the adoption rate for the business.
Substitute,
Refund, or
Preference
on each item
Users can select between 3 options on a single screen without navigating back and forth, providing flexibility for those with allergies or specific substitution requirements.
For legal and safety reasons, the guidance for users with allergies is prominently visible.
Additional details on the impact of each options (substitution, refund, or preference on each item) are available under the ‘Show more’ link, as users want to understand this information, as previously identified from research.
Allergy & other info
Retrospective
I put myself forward to lead the design of the substitution feature for my growth. It was a challenging project with a complex and broad scope, involving 80+ colleagues across 3 teams, along with time pressure from the business.
However, I managed stakeholder relationships through proactive alignment and open discussion, quickly suggested solutions when disagreements arose among PMs, and iterated designs based on 163 Figma comments.
This contributed to effective communication and collaboration between 6 PMs, 2 design managers and 2 designers across teams, ensuring faster development and saving €1,234,552 for the business. This success was celebrated by senior leadership, including CPO and Senior Director of Product.
Feedback from the Principal Product Manager (initiative lead)
“Eunbi is in my top 3 of designers within JET I have been working with so far.
Overall very happy with the work that Eunbi did for substitution and enjoy working with her!
What I appreciate about Eunbi the most are
1. work ethics (very motivated, proactive, on top of things, organized, delivers what she promise) and
2. design quality (focus on customer understanding and problem to solve, usability testing, iteration based on feedback, competitor analysis, convincing others on the way to go supported by data, clear feedback on dev work).
Very proactive example is that she included her substitution work in another usability test to get feedback on-time. Also she showed a lot of flexibility in the scope changes we made.”
Thank you!