The document discusses decentralized finance (DeFi) and developing interfaces for blockchain-based financial protocols. It provides an overview of DeFi, including how it works without intermediaries by using open source protocols on Ethereum. Major DeFi applications currently include lending/borrowing platforms like MakerDAO and Compound. The presenter then discusses a service they developed to aggregate cryptocurrency portfolio data across protocols. They propose future work to automate portfolio management and showcase additional DeFi applications their system could support.

1. Developing an interface
for blockchain-based protocols
in decentralized finance
applications
Daisaku Yamamoto
TimeTicket, Inc.
ethcon Korea

2. Daisaku Yamamoto
Director, TimeTicket
Tokyo, Japan
Twitter @daisaku
P2P skills
marketplace

3. Developers should create
financial services on Ethereum
right now

4. What is DeFi
(Decentralized Finance)

5. What is DeFi
A movement that uses open source and distributed
networks to transform traditional financial products
into a reliable and transparent protocol without
intermediaries.

6. Traditional finance
Financial intermediaries
Decentralized finance
• Requires trusted, centralised
intermediaries
• Batch clearing and settlement
• Higher fees and costly infrastructure
Blockchain protocol
• No intermediaries required
• Faster processing and management
• Lower fees and reduced infrastructure
cost
Source:Blockchain for Digital Transformation in Banking, FLOYD DCOSTA

7. Unbundling of financial intermediary functions
Lending/Borrowing
Investing
Exchanging
Transferring
Traditional
Banks
Banks/Exchanges
Exchanges/Brokers
Cash
Fintech
Lending Club
Robinhood
TransferWise/Revolut
DeFi
Tokenized P2P Debt
Tokenized financial
Products
DEX
Cryptocurrency

8. Benefits
Benefits and Concerns of DeFi
Concerns
• Permissionless
• Censorship Resistant
• Immutable
• Reduced Counterparty Risk
• Transparent
• Open Source
• Programmable
• Efficiency
Source: Decentralized Finance (DeFi) Thematic Insights, Delphi Digital
• Regulatory risks
• Limited product/market fits
• Potential for high
spreads & low liquidity
• Limited on-chain throughput

9. DeFi Map
Source: Mapping out Ethereum’s DeFi, THE BLOCK
Payments
Infrastructure
KYC&Identity
Stablecoins
Insurance
Custodial Services
Exchanges&Liquidity
Investing
Derivatives
Maketplaces
Prediction
Markets
Credit & Lending
100+

10. The total usage volume of DeFi
Locked about 2.2% of total ETH
Source: https://mikemcdonald.github.io/eth-defi/ Source: https://defipulse.com/

11. Major services of DeFi
MakerDAO
CDP Portal
https://cdp.makerdao.com
83% of ETH locked of DeFi
Compound
https://compound.finance
4% of ETH locked of DeFi
Dharma
https://www.dharma.io
4% of ETH locked of DeFi

12. A use case of MakerDAO
Margin trading
(Long position on the ETH/DAI pair)
MakerDAO
CDP Portal
Exchange

13. A Service I have developed

14. A problem that I felt using DeFi
Portfolio management is difficult

15. A service to aggregate crypto asset information
• account balance and
transaction history
• present value
• DeFi portfolio
Watch your all crypto portfolio in a single page
Cross protocol position
monitoring

16. Demo movie

17. System
EthereumMy AppUser
Ethplorer API
Ethereum tokens data
LoanScan API
DeFi activities data
CoinMarketCap API
Cryptocurrency data
Etherscan API
Ethereum accounts data
• DONE: Monitoring account balance and transaction history
• TODO: Automatic aggregation of DeFi portforio

18. Crypto Asset Management services
InstaDApp
https://instadapp.io
Zerion
https://zerion.io
Fetch
https://hellofetch.co
Blockchain-based protocols for DeFi

19. Future Development
My AppUser
Ethereum
Smart
contracts
Lending, Borrowing, Exchanging, Transferring

20. Automated Portfolio Management
My AppUser Smart
contracts
Automatically selects protocols
with higher annual percentage rate
Lend APR
11.0%
Lend APR
13.6%
Lend APR
15.67%

21. Future of DeFi
System infrastructure
Users
Company
Financial
Services
Chances in the gap

22. Developers should create
financial services on Ethereum
right now

23. Thank you!
ethcon Korea
Daisaku Yamamoto
Twitter @daisaku