Merpay Backend Introduction - Mercari India DEV Meetup #01 Backend

WE ARE HIRING!!
https://careers.mercari.com/hello-india/

This is a team introduction of Merpay Backend.
Merpay, Inc. was established in November 2017 as a fully-owned subsidiary of Mercari, Inc., with the goal of starting a new business related to finance. Merpay’s mission is to build trust for a seamless society. Using the technological know how, vast user base, and foundation of data from the marketplace app Mercari, the company’s goal is not only to provide Merpay as a method of payment, but to create a new form of trust that could be used to provide various other financial services in the future.

This slide was presented at the first Mercari India DEV Meetup on the 20th August to introduce the Backend teams of Mercari group. The recording can be viewed from the link below.
https://youtu.be/w_khQWGhzic

- Speaker LinkedIn account
Karuna Murti: https://www.linkedin.com/in/karunamurti/
Rory How: https://www.linkedin.com/in/roryhow/

Please follow us on our LinkedIn account for the latest information!
https://www.linkedin.com/company/mercari-india/

#Engineering #MercariIndia #Backend

Transcript

1. By Karuna Murti & Rory
   @ Cash I/O Team & Payment Team
   Merpay Backend Introduction
   

   View Slide

2. Self-Introduction
   My name is Karuna Murti
   I’m from Indonesia
   Working in tech since 2005
   Worked with people from
   dozens of countries and dozens of cultures
   Hobby is hiking and Star Trek
   

   View Slide

3. Self-Introduction
   Hi, I’m Rory! 👋
   Originally from the UK, in Tokyo since April.
   Studied Computer Science at universities
   in the UK and Finland
   Working history primarily in tech consulting
   as a SWE
   Passionate about skiing, formula 1 and running
   

   View Slide

4. 　　
   Businesses

   4
   

   View Slide

5. 　　
   Merpay　
   5
   

   View Slide

6. Mission
   

   View Slide

7. What is Merpay?
   Merpay is a mobile payment service
   brought to you by the creators of
   Mercari, Japan's largest C2C
   marketplace app. It is operated by
   Merpay, Inc., under the Mercari Group.
   With Merpay, users can make payments
   on Mercari and at 2.64 million stores
   nationwide, by using the money earned
   from selling items they no longer need
   on Mercari, charging money from their
   bank accounts, or using Merpay Smart
   Payments.
   7
   

   View Slide

8. Mercari Group’s “Circular Finance”
   画像の英訳：
   好きなこと・やりたいこと＝ User’s dreams
   出品 = List
   モノ = Items
   お金 = Money
   決済 = Payment
   信用 = Credit
   利用実績 = Usage history
   信用情報 = Credit information
   売上金= Sales balance
   The addition of Merpay to Mercari’s item lifecycle creates a circular relationship between users’ items,
   money, and credit, facilitating the growth of “circular finance” that grants users greater freedom and
   flexibility. It provides users with a valuable, uniquely Mercari experience. 

   8
   

   View Slide

9. Merpay’s Three Focus Areas
   ● Lump-sum payment:
   　Defers payment to the following month
   ● Fixed-amount payment:
   　Pay in installments over several months
   ● Started services allowing users to
   　use their Merpay balance for
   　asset management and more
   Payment Credit Growing Wallet
   Lump-Sum
   Payment
   Fixed-Amount
   Payment
   Asset Management
   Pay for everyday
   purchases all at once
   the following month
   Treat yourself now and pay
   over several months at a fixed
   amount of your choice
   ●Providing a virtual card in addition
   to iD payment and code payment
   iD
   Code
   Payment
   Hold your phone over
   a reader
   Scan a code
   Virtual Card
   Input a number
   1. Launched March 3, 2021
   9
   

   View Slide

10. Payment
    

    View Slide

11. Merpay's Users
    The number of Merpay users1 is 12.92 million, with an 80% retention rate for first-time users2.
    1. Total number of unique users who are registered for Merpay Electronic Money, or used Merpay Code Payments, Online Payments, Merpay Smart Payments, etc. as of Sep 2021.
    2. The ratio of unique users who made a payment using Merpay for the first time at an offline merchant in May 2019, and made a payment using Merpay again the following month.
    This does not include users who made their first payment entirely using points awarded for free.
    Retention Rate of First-time Users
    Number of Users
    Over 12 million
    Merpay users
    11
    

    View Slide

12. *Includes select store locations where Merpay is not available.
    Merpay's Merchants
    2.64 million locations nationwide (March 2022)
    and more...
    12
    

    View Slide

13. Primary ↔ Secondary Distribution Cycle
    Receive money for
    sale/charge balance
    Receive item
    Sell unneeded
    items on Mercari
    Purchase new items
    using Mercari sales
    balance, etc.
    13
    

    View Slide

14. How to pay for something in Merpay
    ● Merpay balance
    ● Bank transfer
    ● Credit Card
    ● Apple pay
    ● Deferred payments
    ● Monthly installments
    ● Points from third party systems
    And others….
    But all of these need to work
    consistently, reliably and provide a
    good experience for our users.
    We also need need to ensure our
    systems are secure, and easily
    auditable. 14
    

    View Slide

15. Payment Core is the “beating heart” of these
    transactions
    For all items bought on the Mercari app or sites…
    For all payments made using Merpay to buy items…
    We will make sure that money goes from place A to place B
    quickly and securely.
    That’s A LOT of payments to handle!
    15
    

    View Slide

16. What kind of things do we deal with?
    Scalability - our features need to be able to
    operate efficiently for our millions of users. Even
    small changes can have a large impact on the UX
    of Merpay!
    Transactional consistency - how can we ensure
    that when something goes wrong, all of our
    backend microservices have been correctly
    updated?
    16
    

    View Slide

17. So, what have I enjoyed the most?
    ● Helping Japan move towards a cashless society
    ● Working on products with scale
    ● Always new challenges, new features and room to grow
    ● Great colleagues!
    17
    

    View Slide

18. What Cash I/O team do
    Cash I/O responsibility is connecting Mercari Group
    ( Mercari, Merpay, Mercoin, Souzoh, etc )
    with financial institutions
    (Banks, ATMs)
    and managing the connections afterwards.
    18
    

    View Slide

19. What Cash I/O team do
    Cash I/O major functions
    Cash In
    - Funds Recharge
    - Topup
    Cash Out
    - User Payout
    - Partner Payout
    19
    

    View Slide

20. Cash In
    Functions
    - Bank Account Registrations
    - Funds Recharge
    - Providing data to other services
    - Connecting hundreds of banks (300+)
    - Handling … funds recharge requests / s
    - Ensuring the availability and reliability
    of the services
    - Ensuring people’s money is in the
    right place
    

    View Slide

21. Cash In
    21
    

    View Slide

22. Cash Out
    Processors
    User Payout
    Partner Payout
    22
    

    View Slide

23. Credit
    

    View Slide

24. Merpay Smart Payments - A Credit Service Based on “Trust”
    *Deferred payment is not available to users under the age of 18. Users 18 or 19 years of age also have an upper usage limit of 50,000
    yen and require the consent of their parent or guardian.
    Fixed-amount payment is not available to users under the age of 20. Total usage limit for deferred + fixed-amount payments is
    300,000 yen.
    24
    

    View Slide

25. Merpay Smart Money - Small-sum Loan Based on Mercari Usage
    *Maximum borrowing limit is
    200,000 yen. Interest rate and
    borrowing limit are
    determined through a
    screening process based on
    the user’s Mercari usage
    history. Not available to users
    less than 20 years of age or
    over 70 years of age.
    25
    

    View Slide

26. Growing Wallet
    

    View Slide

27. Merpay Engineering Organization
    

    View Slide

28. Organizational Structure
    Cash-out Merchant Platform
    Product classification
    Backend 1
    Backend 2
    iOS
    Android
    Functional classification
    PM PM PM
    TL
    TL
    EM
    EM
    EM
    EM
    TL
    28
    

    View Slide

29. Architecture
    Tech Stack
    ● Microservices
    ● Google Cloud Platform
    ● Kubernetes (GKE)
    ● Cloud Spanner
    ● Go
    ● gRPC
    29
    

    View Slide

30. We Are Hiring!
    

    View Slide

31. New Tech
    Big Scale
    Grow Together
    The Charm of Merpay
    31
    

    View Slide

32. Who share the mission of “Building trust for a seamless society” and want to
    commit to it together with us.
    Who are willing to understand the complicated and difficult FinTech domains
    and has the passion and confidence to solve the social problems with
    technology.
    People we want
    32
    

    View Slide

33. Thanks!
    

    View Slide