Design a mobile app that allows users to easily buy and sell used books.

Question

Design a mobile app that allows users to easily buy and sell used books.

Define facts like what is the scope of the app, who would be the audience etc.

Break down the problem into parts (Define the different types of users, what actions can a user take and what this would result in).

Think of an end to end solution for different kinds of possible users for this app. Think about what elements you think should be there on any given app screen and what would be the user journey. (Wirefeames & user flows)

Screens & Information architecture (What options will be shown where, how will one screen be linked to the other)

User flows for different scenarios and user types

Asked at Google over a year ago

4.3k views

Product Design category

Asked at

4.3k views

How to answer Product Design questions

Interview Guide

Top Product Design interview questions

How would you design a web search engine for children below 14 years old?36 answers | 42.9k views
Design a library for the future.25 answers | 23.5k views
How would you design a consumer application for a scooter sharing business?21 answers | 18.6k views
See Product Design PM Interview Questions

Invite members
Invite by email

Add another

Bharat Rathi · Answer 1 · 2020-05-13T03:52:16+0000

Clarifying question-

· Is it applicable for any specific segment or cohort of the users?

o Interviewer - No, applicable for everyone using phone.

Geography – US Market

· What type of books will be traded on the site?

o Interviewer- All kind of Physical books across genres

· Is there any specific similar service available in the market? If yes, what is the problem with current service

o Interviewer – There is no dedicated online marketplace available to Buy and Sell used books.

Solution - I will segment the Book readers in to a specific matrix to define the MVP segment so that Product can be launched in a seamless way

	Course Book	Fiction	Non-Fiction
5- 18	MVP 1	MVP 1
18-25	MVP 1	MVP 1
25-40	MVP 1		MVP1
40-55			MVP 1
55

Justification for the Age group and Genre for the MVP 1

1. Age 5-40 are very friendly with Mobile devices and are open to use new apps

2. Course books can be easily commoditized i.e. - A student will be willing to sell of his books once he/she has passed a specific grade and a student joining the same grade will welcome to buy such books are cheaper price

3. Fiction ( Sub-genre ==> Comics) is the most popular and most circulated category amongst the 5-25 age group and it

4. To ensure that the App is not being branded as a Course book and Comic trading marketplace- Targetting 25-55 age group with Non-fiction genre is important

Product Design-

Features	Urgency	Ranking
Frictionless account creation · Sign up with email address Create Profile- Seller/Buyer Set your interests	Must Have	1
Search Book Genre Seller Author	Must have	2
Cart Management	Must Have	3
Secure Payment	Must Have	3
Review Book Author Seller	Should have	4
Return or Cancel	Could Have	6
Similar books	Could have	7
Share your book catalogue Allow users to share the books ready for sell Allow users to share the upcoming books	Must Have	2
Number of people watching the book	Could Have	8
Book FAQ	Should have	5

Alan · Answer 2 · 2020-04-14T22:26:07+0000

Clarify the question.
1. Is there a specific demographic age you want to focus on? Children's book, Adult, etc.? Nope, all age is fine
2. Is there a location to focus on? Up to you
3. A specific customer segment? Define it.
Customer segment:
1. students purchase books for their class (Middle school and above)
2. Avid book enthusiasts
3. Parent's reading to their children
Prioritize my focus on #1 - the student who purchase books because this seems to be a problem when I was a student myself and would like to provide some solutions to fix this.
Painpoints of students purchasing books for school.
1. Expensive
2. Purchase the book for a few months and is left untouched or thrown away
3. A hassle purchasing the book and edition required
4. Sold out
Some potential improvements to the pain points:
1. Create an algorithim similar to Slickdeals on the new mobile application that will analyze the cheapest option of the same product, but this application will make it a few dollars cheaper for the students.
2. and 3. Create this mobile platform where students know will take the class next quarter or semester to join the wait list. This will generate a notification to the student who has the book and will be selling the following quarter. Once there is a match similar to Hinge (both parties agree on buying and selling), they can chat and proceed with the transaction.
3. If the book is sold out or not enough sellers out there, the application will provide additional resources such as an E-version from the mobile book application to reduce competitos.
I think I would focus on #1, #2, and #3 for the sake of a student in debt and having trouble finding the book that they need and those who don't know what to do with their book after finishing the class.
Product vision Step by Step:
1. Student downloads and signs up for the application
2. Prompt user to verify their school, school email, address, and a profile picture
3. Enter credit card information (if under 18, enter parent's information with same verified information)
4. Sellers will post the books they have for sale and the application will give them the highest price they can sell for with location they are at
5. Buyer filters the application for location and book. Once they join the wait list for that specific book,
6. Matches the seller and they can chat and proceeed with the transaction (Like dating apps)
7. Note: Seller is still finishing class, but allows him to know that he can has already sold the book 4 weeks in advance (Reduces the hassle already). Buyer does not have to stress buying a book last minute and has it 4 weeks before class begins.
Pit Falls:
1. Sellers may result to other competitor sites because they can sell for more
  1. Answer: Amazon and other websites take a large percentage, which becomes the same price. In addition the ease and accessibility on this mobile platform gurantees book being bought and sold
2. Seller does not sell or loses the book
  1. Answer: Seller to refund the money directly to the buyer without needing to meet each other as everything is done through mobile credit card transaction process (no cash)
Metrics: DAU, MAU, Converstion rate, Retention rate, application feedback

talkhuda · Answer 3 · 2020-07-04T19:40:03+0000

We would like to design a mobile app that allows users to easily buy and sell books. This makes it more convenient for them to find books that they want, recycle the books that they have with being cost and time efficient.

Goal of the app is to get as much number of books bought and sold through the platform.

User personas:

Buyers

Sellers

And some that could be both

Let’s assume that the seller is most likely a buyer in this case.

We can look at different type of use cases:

Academic – students

Academic - professors

Fiction

I will focus on the students since they will be the highest in terms of frequency of usage. They are tight on money and need to sell

User needs:

1. Create account

2. Create Product

3. Search Product

4. Make a Payment

5. Fulfill Product

6. Product review

7. Returns and cancellations

Given this is the MVP, what the focus needs to be on based on priorities is 1, 2, 3 & 4

Solutions:

1. Seamless account creation

2. Upload image of the book

3. Input price and shipment costs

4. Optimize the image

5. Auto suggest a price for the book based on comparable (AI)

6. Paypal integration

7. Provide shipment label

8. Filter buyers within a certain radius

9. Offer different methods of fulfilment: pick up, shipment

	Frequency of usage	Impact	Value	Effort
Seamless account creation	High	High	High	low
Upload image of the book and price	High	High	High	Low
Input price and shipment costs	High	High	High	low
Optimize the image	High	High	Low	High
Auto suggest pricing	Medium	Medium	Medium	High
Paypal integration	High	High	High	Medium
Provide shipment label	High	High	Low	Medium
Filter buyers	Medium	Medium	Medium	Medium
Different methods of fulfilment	Medium	High	Medium	high

Based on the above, I would focus on 1, 2, 3 and 6.

To summarize, since this is an MVP, focus should be on account and product creation and payment.

Amit Aggarwal · Answer 4 · 2020-05-15T16:35:19+0000

Clarifying questions

1. What the users are trying to do?

2. Who are the user group

User groups:

1. Sellers

Customer Segments

1. Readers who have used their books like Students

2. Dealers who want to sell the used books like online Oxford Booksellers

2. Buyers

Customer Segments

Readers who want to buy the used books

Customer Needs of the seller group ( including both customer segments )

1. Upload the books to sell on the portal

2. Provide the information of the which buyer might be interested in before buying the book like description, price, condition

3. Update the payment information where money should be deposited after being sold.

4. Refund the money of the buyer in case of conflict

5. Enable or disable the book review

6. Make the particular book out of stock

7. Accept payment on the portal itself

8. Seller want to monitor the number of visitors

9. Enable or disable the chat with the customers to clear their doubts

10. Enable or disable the question and answer with the customers to clear their doubts

10. The seller would like to know about the questions raised by the customers so that it can be answered.

12. Reduce the cost of the cost incurred for delivery of the book

13. Sell the book at a good margin possible.

14. Modify the account information

15. Change the price of the books

16. Protection against the fraud transactions

17. Manage used books inventory when multiple books are available to sell

Customer needs of the buyer group ( Including all customer segments )

1. Search for the book based on book attributes like title, description, ISBN

2. Filter the book based on the condition of the book

3. Filter the book based on the price range

4. Compare books from multiple sellers based on price, condition of book, refund policy etc

5. Get the book delivered

6. Clarify the questions and answers from the seller

7. Notify as soon as seller answers his/her questions

8. Buy the book in the best condition but in minimum price

9. Search for a book on the portal through image search

10. Rate the seller

11. Get informed when the book of his/her interest comes in stock.

12. Buyer want have payment options on online as well as cash on delivery

13. Cancel the order within a given timeframe

14. Get the money refund.

Minimum Viable Product

Target Customer segments in MVP 1. Seller Customer Segment

1. Readers who have used their books like Students

2. Buyer

Customer Segment

1. Readers who want to buy the used books

Prioritize the customer needs of the seller group

Customer Needs	Customer Segment	Priority
Reduce the time it takes to upload the book information on the portal	Readers / Dealers	Must Have
Provide the information of the which buyer might be interested in before buying the book like description, price, condition	Readers / Dealers	Must Have
Refund the money of the buyer in case of conflict	Readers / Dealers	Must Have
Change the price of the books	Readers / Dealers	Must Have
Receive the payment in the account when books are sold	Readers / Dealers	Should Have
Enable or disable the question and answer with the customers to clear their doubts	Readers / Dealers	Should Have
The seller would like to know about the questions raised by the customers so that it can be answered.	Readers / Dealers	Should Have
Protection against the fraud transactions	Readers / Dealers	Should Have
Enable or disable the book review	Readers / Dealers	Could Have
Sell the book at a good margin possible.	Readers / Dealers	Could Have
Modify the account information	Readers / Dealers	Could Have
Enable or disable the chat with the customers to clear their doubts	Readers	Could Have
Accept payment on the portal itself	Readers	Wont Have
Make the particular book out of stock	Dealers	Could Have
Seller want to monitor the number of visitors	Dealers	Could Have
Reduce the cost of the cost incurred for delivery of the book	Dealers	Could Have
Manage used books inventory when multiple books are available to sell	Dealers	Could Have

Prioritize the customer needs of the buyer group

Customer Needs	Customer Segment	Priority
Search for the book based on book attributes like title, description, ISBN	Readers	Must Have
Get the money refund.	Readers	Must Have
Cancel the order within a given timeframe	Readers	Must Have
Filter the book based on the condition of the book	Readers	Should Have
Filter the book based on the price range	Readers	Should Have
Clarify the questions and answers from the seller	Readers	Should Have
Notify as soon as seller answers his/her questions	Readers	Should Have
Compare books from multiple sellers based on price, condition of book, refund policy etc	Readers	Could Have
Buy the book in the best condition but in minimum price	Readers	Could Have
Search for a book on the portal through image search	Readers	Could Have
Rate the seller	Readers	Could Have
Get informed when the book of his/her interest comes in stock.	Readers	Could Have
Buyer want have payment options on online as well as cash on delivery	Readers	Could Have

Solution

1. Allow buyers and sellers to signup to the portal through facebook and google.

2. Sellers can upload the book data through mobile. Sellers can scan the ISBN number of the book to fill the standard information which is needed by the portal.

3. Sellers can set the price of the book.

4. Sellers get notified if any question is posted by the buyer so that buying process can be expedite.

5. Disimburse money to the sellers after certain locking period.

6. Allow buyers to search for the book based on title, descriptions and condition of the book

7. Buyers can filter the books based on the product price range.

8. Buyer can post a question to the seller which could help him to expedite the buying process.

9. Allow buyers to add the product to the cart

10. Allow buyers to order the book

11. Buyers can cancel the order within given lockin period.

Product Metrics

1. Average time taken by the sellers to register on the app

2. Average time taken by the buyers to register on the app

3. Average time taken by the sellers to upload the product

4. Click through rates on the book search page.

5. Number of orders cancelled per month

6. Number of questions resolved per month

7. Average time taken by the seller to answer the buyers questions

8. Number of refunds requested per month

Business Metrics

1. Number of successful orders per month

2. Number of Refunds per month

3. Buyers Acquisition Rate

4. Sellers Acquitision Rate

5. Seller LTV

6. Buyers LTV

RS. · Answer 5 · 2020-05-15T01:24:02+0000

Clarifying questions:

Do we sell only hard copy books? - Yes
Do we sell anything else? - No
Goal of the app - Revenue or user adoption? - User adoption
Any target market or geography? - you decide
1. can I assume all market segments in the US? - sure
Is it only to list (like craigslist) or complete the transaction (like eBay) - let's see based on time
Target platforms? you suggest

User Segments

Based on the types of books studied, I see the following categories:

Academic
- maths, science, grammar, etc.
Professional
- programming courses, interview prep guides, etc.
Fiction
- novels, kids' reading books
Hobbyists
- health and hygiene, art, culinary, etc.

I believe the above segments are also in order of their priority since I believe students are the most popular used books buyers. They are biggest consumers for books, they are low in disposable income and use the books for a short period. Hence the biggest target segment. However, we are expected to target all segments. I will use this as a representative user keeping in mind the needs of all users. Does that sound okay? - Yes

User Needs

Get rid of books after use
Buy used books in time - time is a need for students, more than others
Safe transaction - especially with professionals who might be buying from complete strangers
Review the book's condition
Feedback on the book - especially for fiction and hobby readers
eBay like - online purchase and shipping options

Solution and prioritization

to get rid of the books, the user must register as a seller. Listing of books could be form-based or AI-based that will do a quick search from uploaded photos to tag and categorize books and potentially gauge the condition to rate it. While the latter is amazing and is a capability that is doable, it will take a much longer time. If are plannig to build an MVP, this could be put away for a while.
Users to be able to register as buyers. This registration could also be form-based or upload of an ID card to automatically validate and register users.
For ensuring a safe transaction, I would have the following considerations
1. ID verification - driver's license, etc.
2. Phone number validation
3. Optional photo upload
4. Reviews received from other buyers/sellers
- while i would recommend usign this to authenticate users, I would reveal this info only on a need-basis like Airbnb releases the phone number and address only after a successful booking. btw, by "I" I meant the app.
Reviews - this would be self- appraised condition of the book like eBay. However, unlike eBay that deals with a multitude of items, here we are considering only books. So, we could ask for a questionnaire to be filled to gauge the condition and provide details to the buys.
- on reviews, I would also consider the option to provide review/feedback by buyers and sellers on the app to give an overall rating to the user.
Feedback on the books can be provided by
1. other users, including the seller - this makes it more personal and more relatable. But it would take time to build up and wouldn't be able to add value in the meanwhile.
2. sought from other websites - this is more standardized, which users will be able to seek outside of the app. However, if we could easily link to another seller (like Amazon that sells new books of the same), and get the rating/review (like IMDB allows to), it would be good. Antoher consideration over here is that we cannot source it from multiple sources for different books because then the reviews wouldnt be standardized for our users

Metrics:

Primary: # of new users per month

Secondary: MAU, # monthly transactions/user, # of books unsold for more than a month (studying them will help to evaluate if we are not having enough buyers or whether need price guidance), # of searches NOT resulting in purchases ((studying them will help to evaluate if we are not having enough sellers or whether need price guidance)

If the above path looks good and we have some time, do you want me to move to the eBay plan and evaluating which platform to go first? - sure

eBay Plan: To provide an end-to end experience, the app could also provide options like UPS pickup/drop off/printing labels and books could be sold. To measure the use of this, I would focus on %sellers listing and %buyers (who have this option) choosing this option.

Mobile Platform: since the target market is in the US where iOS is the market leader, I will recommend going with iOS app if we have to choose which platform to adopt.