Purchases API and Dashboard

Configurable insights about users and purchases.

Insights

Dashboard provides information about users activity and purchases based on the date selected by user and configuration options in config. Please find queries explanation in scripts directory.

Users activity

Depending on user behaviour and configuration options, dashboard highlights three types of users: active, churned and inactive.

Active

User is considered active when he made X purchases during last Y days/weeks/months. See query explanation.

X = config.activitySettings.activePurchases
Y = config.activitySettings.activePeriod

Churned

User is considered churned on a day when his last purchase was between X and Y. See query explanation.

X = SELECTED_DATE - config.activitySettings.churnDelay
Y = SELECTED_DATE - config.activitySettings.churnDelay - config.activitySettings.churnDuration

Inactive

User is considered inactive when his last purchase was earlier than churning start point X. See query explanation.

X = SELECTED_DATE - config.activitySettings.churnDelay - config.activitySettings.churnDuration

Purchases statistics

Dashboard displays number of users who made purchases on selected day, on that’s day week and month, and in period from that day till today.

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Tools and technologies

Backend

• Node.js and Express
• MongoDB Native Node.js driver
• ava.js for testing

Frontend

• React with help of create-react-app
• SCSS

Frontend part is located in separate repository meetfrank-assignment-frontend.

Installation, running and testing

Prerequisites

$ node -v
v10.13.0

$ mongo --version
MongoDB shell version v3.6.3

$ yarn -v
1.12.3

Installation

1. First, install dependencies: yarn.
2. Make sure your mongod is up and running.
3. Then restore database from dump: yarn restore.

Running

1. yarn start
2. Visit http://localhost:3000

Testing

1. yarn test

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Demo

Demo video

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Further improvements

Fix date selecting on iOS

For simplicity now user selects desired date using <input type="date">. On iOS Safari, native datepicker lacks support for min and max attributes. When user picks date that is out of available data boundaries, it just reverts to first or last available date.

Improve caching mechanism

For simplicity, all heavily calculated data is cached and stored in app.locals. There’re definitely better cache storage choices.

Provide trends on activity stats

There’s possibility to provide some kind of trend information about user activity, e.g. number of active users dropped by 4%.

Elaborate more metrics

Like activity rate or churn rate