How do you handle out-of-stock and substitutions?

We build substitution logic into the picker app with customer-controlled preferences per product category. When a preferred item is unavailable, the picker offers an approved alternative in real time and the customer approves or declines before the order is packed.

Can you build for both delivery and click-and-collect?

Yes, and many clients run both from the same platform. The order routing logic differs between fulfilment methods, but the catalogue, customer account, and picker app are shared. We scope both together from the start rather than building one and retrofitting the other.

How do you handle age-restricted products?

Age verification for alcohol, tobacco, and other regulated categories is built into both the checkout flow and the picker and driver handoff. The specific verification method depends on your state’s requirements, confirmed during discovery.

How long does it take to build a grocery delivery app?

Click-and-collect apps typically take eight to fourteen weeks. Full delivery platforms with picker apps, driver dispatch, and inventory sync take twelve to twenty weeks or more depending on catalogue size and the number of integrations required.

Grocery Delivery App Development Company

Grocery delivery has a different failure mode from restaurant delivery. A missed food order is a disappointment. A grocery order with three substitutions the customer did not want, two out-of-stock items marked available at checkout, and a delivery window that slipped by an hour is a customer who cancels their account and tells their household not to use the service again. The margin for error is narrower because the expectations are more practical.

The operational complexity is also higher. A grocery app is not managing one menu with twenty items. It is managing a catalogue of thousands of SKUs, each with real-time stock levels, weight variables, age-restricted categories, and substitution preferences the customer set three orders ago. Every one of those data points has to be accurate at the moment a picker reaches the shelf, or the order falls apart before it reaches the door.

01

Customer Ordering and Delivery

Browsable product catalogue, scheduled delivery slots, substitution preferences, order tracking, and in-app communication with the picker mid-shop.

02

Picker and Driver App

A dedicated app for in-store pickers with optimised pick routes, substitution workflows, weight capture for variable items, and handoff confirmation before the bag leaves the store.

03

Inventory and Catalogue Sync

Real-time stock levels, product availability, and pricing pulled from your inventory system so customers only see what is actually on the shelf.

Fulfilment from a purpose-built micro-warehouse rather than a retail store, with picking optimised for speed and delivery windows measured in minutes rather than hours.

Customers order online and collect from the store or a designated pickup point, with the picker app managing preparation and a collection notification when the order is ready.

Multiple grocery retailers on one platform, with the customer choosing by store, postcode coverage, or product availability rather than being locked to a single retailer.

Grocery customers who have used Instacart or Amazon Fresh have a reference point. They expect the catalogue to be accurate, substitutions to be offered in real time rather than discovered at the door, and the delivery window they selected to be the one the driver actually arrives in. Missing any of those three does not produce a complaint — it produces a cancellation and a switch to whatever platform does them correctly.

The substitution workflow is where most grocery apps fall short. A customer who selected semi-skimmed milk does not want full fat as a substitution without being asked first. A customer who is lactose intolerant should never receive a dairy substitution for a dairy-free alternative. Building the preference logic and the real-time substitution approval flow into the picker app rather than leaving it to a phone call is what separates a grocery app that retains customers from one that frustrates them.

05 features

Product browse with category, brand, and dietary filters
Delivery slot selection and management
Substitution preferences per product
Real-time order status and picker communication
Order history and easy reorder

Customer ordering with in-store picking and collection notification, without a delivery fleet. These typically fall in the lower five-figure range and launch in eight to fourteen weeks.

Full delivery with picker and driver apps, slot management, and inventory sync for one store or a small chain. These sit in the mid five-figure range with a twelve to eighteen week build.

Marketplace or chain-wide platforms with centralised catalogue management, dark store support, and driver network tooling. These run into the high five and six-figure range.

These are market ranges, not fixed quotes. We give you an itemized number after a short discovery call.

01Discovery

We map your catalogue size, your inventory system, your delivery model, and your picker workflow before any design decisions are made.

02Design

We prototype the customer ordering experience and the picker workflow separately before development, since they have very different interaction requirements.

03Development

We build in sprints with regular check-ins so your operations and store teams can review real picking and delivery flows throughout the build.

04Testing

Every build is tested with real catalogue data and simulated pick scenarios before release so substitution logic and stock accuracy issues are found first.

We build customer and picker apps in React Native or Flutter for both iOS and Android. The backend runs on Node.js for real-time order events and slot management, with PostgreSQL for catalogue, order, and inventory data. Redis handles live order state and slot availability. Payments process through Stripe. Inventory sync connects to your existing ERP or WMS through API integration or EDI where required.

React Native
Flutter
TypeScript
JavaScript
Node.js
PostgreSQL
Redis
GraphQL
Stripe
AWS
Google Cloud
Firebase

01

Inventory Sync Accurate At Pick Time

02

Substitution Logic Built Into The Picker App

03

Slot Management That Reflects Real Capacity

04

Support Through Every Catalogue And Zone Change

Grocery delivery fails at the shelf, not at the checkout. We build the picker app with the same care as the customer app because that is where the order either succeeds or becomes a substitution complaint.

Grocery delivery fails at the shelf, not at the checkout. We build the picker app with the same care as the customer app because that is where the order either succeeds or becomes a substitution complaint.

Grocery delivery fails at the shelf, not at the checkout. We build the picker app with the same care as the customer app because that is where the order either succeeds or becomes a substitution complaint.

Grocery delivery fails at the shelf, not at the checkout. We build the picker app with the same care as the customer app because that is where the order either succeeds or becomes a substitution complaint.

01

Inventory Sync Accurate At Pick Time

02

Substitution Logic Built Into The Picker App

03

Slot Management That Reflects Real Capacity

04

Support Through Every Catalogue And Zone Change

Yes. We integrate with major WMS and ERP systems to pull real-time stock levels, pricing, and product availability. The integration approach is confirmed during discovery based on what your system exposes, before any development is scoped or priced.

Grocery Delivery
App Development

Why The Grocery Delivery Market Needs The Right App