By Michael Sachar, Sr. Manager – Cognizant
     Pradeep Raju, Associate Director – Cognizant
     Raja GT, Cody Shive, John Gunn, and Saurabh Mathur – AWS

Connect with Cognizant-2

Today’s retail landscape continues to evolve, and eliminating shopping friction is pivotal to every retailer’s digital transformation.

Retailers continue to incorporate new technologies that reduce customer wait times at checkout while enhancing the overall in-store shopping experience. Until recently, most retailers have looked only to reduce friction at checkout; however, we’re seeing a shift to eliminating technology barriers, even at self-checkout, which is a technology shoppers have tolerated but still find cumbersome to use.

The first Amazon Go store opened its doors to the public in 2018, and the world had its first glance into the future of checkout-free retail—a world where customers simply walk into a store, choose an item from the shelf, walk out, and have a receipt of their purchases e-mailed within minutes.

Since then, we have seen retailers shift their sights from bettering their fleet of self-checkout robots to eliminating lanes altogether. But how does this technology fit with a legacy point-of-sale (POS) system that wants either a cashier to hit the “Total” button or the consumer to press “Finish and Pay” at a self-checkout?

To make Amazon’s shopping technology available to all retailers—so shoppers no longer must wait in line—Cognizant built a packaged solution for Amazon’s Just Walk Out technology called Cognizant Customer Concierge Solution. With this solution, Just Walk Out technology can integrate with existing POS and order processing systems, so retailers can quickly integrate “grab-and-go” capability with ease.

Cognizant’s solution, a platform built on Amazon Web Services (AWS), gives you the option to connect Just Walk Out technology with your existing systems including POS, Enterprise Resource Planning (ERP), Mobile Device Management, Customer Data Platform (CDP), and more. In addition, Cognizant offers a white-labelled shopper mobile app that retailers can brand as their own.

Cognizant is an AWS Premier Tier Services Partner and Managed Service Provider (MSP) that transforms customers’ business, operating, and technology models for the digital era by helping organizations envision, build, and run more innovative and efficient businesses.

Amazon Retail Integration Models

Just Walk Out technology provides flexible deployment options grouped in several retail integration models, allowing retailers to choose which functions Just Walk Out technology will perform and which will be delegated to the retailer to perform. Such functions include shopper identity, fraud and abuse checks, order and payment processing, and post purchase (receipts, returns, etc.).

This post focuses on one retail integration option: App Full Delegation (available in UK and US as of this writing). With App Full Delegation, Just Walk Out technology provides the gates and pedestal hardware, builds the virtual cart, and sends it to the retailer. All other retail functions are delegated to the retailer.

Cognizant actively facilitates the streamlined process of the App Full Delegation model using the Cognizant Customer Concierge Solution for Just Walk Out technology.

How it Works

At the core of the Cognizant Customer Concierge Solution is the Cognizant Retailer Technology Accelerator, which provides options and flexibility for managing orders, catalog, payments, and receipts. It also extends Just Walk Out technology’s functionality with support for loyalty and promotions, user identity, and transaction logs.

The Cognizant Retailer Technology Accelerator accomplishes this by supplying connectors required to interface with the retailer’s various systems.

The example below illustrates how the Cognizant Retailer Technology Accelerator works when using the Just Walk Out technology App Full Delegation Retail Integration model.

High Level view of the Cognizant Customer Concierge Solution for Amazon Just Walk Out – App Full Delegation Figure 1 – Customer Concierge Solution for Just Walk Out technology App Full Delegation.

As shown above, depending on the retailer’s systems different connectors are configured for bi-directional communication. Otherwise, they forward communication to downstream applications.

Bespoke integrations may be required, depending on the legacy system. However, Cognizant provides easy options for pub/sub and other flat-file capabilities, such as CSV file interchange. It also includes reporting and logging adapters for Splunk and Datadog solutions.

Business Flow

The Cognizant Customer Concierge Solution for Just Walk Out technology supports a complete frictionless shopping journey. Using the App Full Delegation Retail Integration model, at the end of the shopper’s journey, their virtual basket contents are forwarded by Just Walk Out technology to Cognizant connectors. From that point, the Universal connectors come into play, interfacing directly with the retailer’s existing POS system.

Cognizant Customer Concierge Solution for Amazon Just Walk Out technology App Full Delegation Business FlowFigure 2 – Customer Concierge Solution for Just Walk Out technology App Full Delegation Business Flow.

In Cognizant’s solution, illustrated in Figure 2, the business flow is clearly delineated by business function. Key business area functions are grouped together and include:

  • Retail Mobile App: The shopper entry point, having all of the functions required to work with the Just Walk Out technology store.
  • Just Walk Out technology and Cognizant Retailer Technology Accelerator: This is the dividing point between Just Walk Out technology and Cognizant’s Universal connectors which, in turn, interface with the retailer’s systems.
  • Universal connectors: The gateway to third-party POS systems that provides standard integration points allowing both commercial POS products, as well as home-grown POS, to connect with the Just Walk Out technology integration layer.
  • Retail POS: The group of services typical for most point-of-sale systems.
  • Big data processing, analytics, and push promotions: Includes an artificial intelligence (AI) promotion engine to engage the shopper with targeted offers. Offers are further refined during the analytics stage, where key performance indicators (KPIs) such as basket and shopper analyses are performed and, where appropriate and opted-in by the shopper, qualified promotions are sent to the shopper.

Architecture Overview

The Cognizant Customer Concierge Solution for Just Walk Out technology architecture leverages more than 20 AWS services to support the App Full Delegation Retail Integration model. As part of this architecture, Amazon provides gates, pedestal hardware, “in-store technology” like sensors and camera, and constructs the virtual cart while the Cognizant solution effectively manages the retailer functions. Customers can enter the store and pay using the mobile app/wallet.

Cognizant Customer Concierge Solution for Amazon Just Walk Out App Full Delegation Architecture Figure 3 – Customer Concierge Solution for Just Walk Out technology App Full Delegation Architecture.

The Cognizant Customer Concierge Solution for Just Walk Out App Full Delegation architecture, depicted in Figure 3, is comprised of eight groups of AWS services, detailed below.

1. Authentication

The shopper registers their account and provides a payment method in the retailer’s app before they enter the store. This is a white-label app that can be customized based on retailer requirements. The shopper can sign in through the Amazon Cognito user pool or federate through a third-party identity.

2. Cognizant QR Code Generation

QR code generation is one of the major components of the architecture. The shopper can create a QR code request using the mobile app. The request will be sent to the Amazon API Gateway and the QR code generator’s AWS Lambda function processes the request, returning the QR Code.

3. Cognizant Identity Connector

One of the critical steps to implement the Just Walk Out technology App Full Delegation model in a retailer’s store is to set up the identity connector. When a shopper scans their QR code at the gate, Amazon’s service calls the Cognizant Identity Connector API and passes the shopper’s identity key. The connector will validate the key and decide whether or not to authorize entry to the store. The identity connector treats each shopper interaction with an entry/exit gate as a unique event ID.

When the shopper scans the QR code, Amazon Just Walk Out technology sends the identity key, authentication event, request information, and store ID to the identity connector using Amazon API Gateway. The requests are then distributed to AWS Fargate clusters via Elastic Load Balancing. The Fargate containers will perform three different functions:

  • Validate the shopper in Amazon Cognito.
  • Perform fraud and abuse checks.
  • Call the payment service provider to reserve a pre-authorization amount on the shopper’s preferred payment method.

If the Just Walk Out technology API request to the identity connector is successful, the gate will open. However, if any checks are unsuccessful the gate will not open; a store associate is required to assist the shopper.

4. Shopper’s Experience

The shopper can begin their journey as soon as they enter the store. The innovative shopping experiences enabled by Just Walk Out technology’s computer vision, sensor fusion, and deep learning capabilities accurately track and manage the entire shopping experience. Just Walk Out technology continuously builds a virtual cart with the items selected by the shopper.

5. Cognizant Ordering Connector

Once the shopper exits the store, Just Walk Out technology sends a request to the Amazon Ordering Gateway which, in turn, sends the virtual shopping cart data to the Cognizant ordering connector.

The Cognizant ordering connector performs various functions, including:

  • Stores the virtual cart information in Amazon CloudWatch and in an Amazon Simple Storage Service (Amazon S3) bucket.
  • Calculates the cart total based on SKUs in cart and stores the cart information in Amazon DynamoDB.
  • If the cart total is successful, AWS Step Functions is triggered and updates the cart information in S3. It makes a payment request to payment service provider, and the payment status is updated in DynamoDB.
  • The updated stream record triggers a Lambda function which generates the receipt and stores it in an S3 bucket. It also publishes a message to an Amazon Simple Notification Service (SNS) topic, resulting in sending messages to both the mobile app and the retailer. The shopper can view the order details and receipt with the mobile app.
  • In the event of a processing issue, the status is updated in DynamoDB, and an alert is sent to the retailer using Amazon SNS.

6. DevOps

Cognizant Customer Concierge Solution for Just Walk Out technology App Full Delegation application software is continuously delivered and integrated using AWS CodeCommit, AWS CodeBuild, AWS CodeDeploy, and AWS CodePipeline. The build process generates Docker containers and deploys them to an Amazon Elastic Container Service (Amazon ECS) cluster. The infrastructure is built using AWS CloudFormation templates.

7. Security and Monitoring

The Cognizant Customer Concierge Solution for Just Walk Out technology App Full Delegation Model is built with security in mind. The solution adheres to the principle of least privilege with AWS Identity and Access Management (IAM) users, roles, groups, and policies. Amazon GuardDuty continuously monitors for malicious activity. The AWS WAF WebACL provides firewall protection to the API Gateway endpoint. Data stored in DynamoDB is fully encrypted at rest, while AWS CloudTrail is enabled to trace all user activity and API usage.

8. Universal Connectors

Universal connectors offer myriad choices for retailers. For example, you can load master data from external data sources into Amazon S3 and DynamoDB. Data source channels such as POS terminals, APIs, or external databases all interface with the application using the universal connectors.

Key Highlights and Value Proposition for Retailers

  • Retail can’t thrive by ecommerce alone. Ecommerce will cease to be a differentiator in the marketplace and blended experience will be the differentiator.
  • Advanced shopping technology from Amazon creates a safe and convenient customer shopping experience.
  • Packaged solution from Cognizant to facilitate implementation of Amazon Just Walk Out Technology in less than 3-4 months.
    • API/microservices-based integrations to POS and other systems.
    • AWS cloud serverless architecture enables a pay-as-you-go model, cost optimization, auto scalability, high availability, and secure and simplified development with event-driven, microservices-based architecture.
    • Pre-built connectors bridge AWS and retailer’s systems.
    • Offering as software-as-a-service (SaaS) model.
    • Offline/stand in processing.
  • Allows for human labor to be repurposed, adding incremental value back to the retailer.
  • Available and can be adopted across formats and verticals: grocery, travel, retail, university campus, sports and event Venues.


For retailers who want a Just Walk Out technology store and need help integrating it with their current point-of-sale (POS) system, the Cognizant Customer Concierge Solution gives you options to lower costs, risk, and reduce time-to-market when implementing App Full Delegation from Just Walk Out technology.

Cognizant puts you in the driver’s seat by doing the heavy lifting for you. Now, all you have to do is turn the key and get started. Learn more about Cognizant on AWS >


Cognizant – AWS Partner Spotlight

Cognizant is an AWS Premier Tier Service Partner and MSP that transforms a retailer’s business, operating, and technology models for the digital era by helping organizations envision, build, and run more innovative and efficient businesses.

Contact Partner | Partner Overview | AWS Marketplace | Case Studies