Case Study — 2025

Pronto
Groceries, redesigned

UX/UI Designer
10 weeks
iOS Mobile App
Redesign / Case Study

01 —

When speed matters, friction is unforgivable

Pronto is a grocery delivery app promising 30-minute delivery. The product worked — logistics were fast, prices competitive, selection solid. But the app itself told a different story: confusing navigation, a checkout flow riddled with friction, and a home screen that buried the most-used features.

Users were abandoning carts at a 61% rate.

This was a self-initiated redesign — I took Pronto's existing app, conducted a full UX audit, ran guerrilla usability tests, and redesigned the three most critical flows: home discovery, product search, and checkout.

The goal: make a fast product feel fast to use.

"I know what I want. I just can't find it. By the time I do, I've given up and called my husband to stop at the store."
— Usability test participant, 31, working mom

02 —

Diagnosing the real problems

I ran a 3-part research sprint: a heuristic evaluation against Nielsen's 10 principles, 5 moderated usability tests with grocery app users (ages 26–44), and a teardown of 4 competitor apps.

Problems clustered around three specific moments in the user journey. Fix those three, and you fix 80% of the experience.

61%
Cart abandonment rate
Primarily caused by checkout friction — unexpected fees revealed at the last step.
4.2
Avg. taps to find a product
Users needed 4.2 taps to find a specific item. Industry best practice is 2–3.
0
Personalization on home screen
The home screen showed the same content to every user regardless of past orders.
Pain 01
Home screen has no hierarchy
Promotions, categories, featured items, and banners compete for attention. Nothing signals what to do first.
Pain 02
Search returns poor results
"Milk" returns 47 results with no smart sorting, no dietary filters, no "buy again" shortcut.
Pain 03
Delivery fee revealed too late
Users only see the final delivery fee on the last checkout step — after entering payment. Rage-quit central.
Pain 04
Order tracking is buried
After placing an order, tracking is three taps deep into Account → Orders → Active. Generates anxiety.

03 —

Before & after

The redesign focused on three screens that carry the most user weight: home screen, checkout, and order tracking.

Screen 01 — Home

Before
  • 5 competing visual zones with no hierarchy
  • Two promotional banners above the fold
  • No personalization for returning users
  • 5-tab nav bar is overwhelming
After
Good morning, Sofia Deliver to: Home ▾ 🛒 🔍 Search groceries... BUY AGAIN 🥛 🥑 🍞 SHOP BY CATEGORY 🥦 🥩 🧃 🍦 🔍 👤
  • Search is #1 element — front and center
  • "Buy again" shortcuts for repeat buyers
  • 3-tab nav — simplified, no cognitive overload
  • Clear hierarchy: task → category → browse

Screen 02 — Checkout

Before
Checkout Subtotal: $34.00 + Delivery fee: $4.99 + Service fee: $2.50 ← surprise!
  • No progress indicator — feels endless
  • All fields on one screen — overwhelming
  • Fees only revealed at the very last step
  • No order summary visible during checkout
After
Checkout 1 2 3 ORDER SUMMARY 3 items · Subtotal $34.00 Delivery fee $4.99 + free over $40 → DELIVERY ADDRESS 🏠 123 Main St, Rochester MI Change address DELIVERY SLOT Today 2–3 PM Today 5–6 PM CONTINUE → Total: $38.99
  • 3-step progress bar — always know where you are
  • Order total + fees visible from step 1
  • Pre-filled address — reduces typing to zero
  • Persistent CTA with running total

04 —

Projected impact

After two rounds of usability testing with 10 participants, results validated every major decision. Task completion improved dramatically, and qualitative feedback shifted from frustration to confidence.

Participants consistently described the redesigned app as "faster," "clearer," and "less stressful" — aligning directly with the brief.

−38%
Reduction in checkout abandonment in prototype testing — from 61% to ~23%
2.1
Average taps to find a product — down from 4.2. Cut in half.
100%
Of participants found their active order immediately — vs. 40% in the original flow

05 —

What I learned

01

Audit before you redesign

The heuristic evaluation before any wireframes revealed that most problems weren't visual — they were structural. Fixing the architecture first was key.

02

Friction has a business cost — make it visible

Tying UX problems to metrics (61% cart abandonment) made the case for change undeniable. Designers who speak in business impact get decisions made faster.

03

The best feature is removing one

Collapsing 5 nav tabs to 3 felt risky — but testing showed users didn't miss anything. Subtraction is underrated.

Portfolio
complete.

Three case studies. Three different design challenges. Three distinct visual systems. This is the range of Paulina Zentella, UI/UX Designer.

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