The time it takes to build an ecommerce app can vary significantly depending on various factors, including the complexity of the app, the features required, the technology stack chosen, the size of the development team, and the level of expertise of the developers involved.

Here is a general breakdown of the different stages involved in building an ecommerce app and the estimated time required for each:

1. Planning and Requirements Gathering: This stage involves defining the scope of the app, identifying the target audience, and documenting the features and functionalities required. The time taken for this stage can range from a few days to a couple of weeks, depending on the complexity of the app and the level of detail in the requirements.

2. Design and User Experience: This stage involves creating wireframes, mockups, and prototypes to visualize the app's layout, navigation, and overall user experience. The time required for this stage can vary depending on the number of screens and the complexity of the design. It can take anywhere from a couple of weeks to a few months.

3. Backend Development: This stage involves building the server-side infrastructure, database design, and integrating third-party services such as payment gateways, inventory management systems, and shipping providers. The time required for this stage depends on the complexity of the backend architecture and can range from a few weeks to several months.

4. Frontend Development: This stage involves implementing the app's user interface, integrating with the backend APIs, and ensuring responsiveness across different devices and screen sizes. The time required for frontend development depends on the complexity of the design and can range from a few weeks to a couple of months.

5. Testing and Quality Assurance: This stage involves conducting various types of testing, including functional testing, performance testing, security testing, and user acceptance testing. The time required for testing can vary depending on the size of the app and the thoroughness of the testing process. It can range from a few weeks to a couple of months.

6. Deployment and Launch: This stage involves preparing the app for production, configuring servers, setting up hosting, and deploying the app to the app stores or web servers. The time required for deployment can vary depending on the platform and infrastructure chosen. It can take anywhere from a few days to a couple of weeks.

It's important to note that these time estimates are general and can vary significantly based on the specific requirements and circumstances of each project. It is recommended to consult with experienced developers or development agencies to get a more accurate estimate based on your specific needs.

References:

• "How Long Does It Take to Build a Mobile App?" - Savvy Apps: https://savvyapps.com/blog/how-long-does-it-take-to-build-a-mobile-app-estimate-timeline
• "How Long Does It Take to Build An App?" - Cleveroad: https://www.cleveroad.com/blog/how-long-does-it-take-to-build-an-app