The functions of different canister smart contracts run on a single call stack. This makes them very insecure, due to re-entrancy, which has been one of the biggest sources of hacks on blockchain to date. Another problem is that transactions must run in sequence, which creates a firm upper bound on transaction throughput. On the Internet Computer blockchain, smart contract calls run in parallel, because smart contracts are "software actors." This removes a key security vulnerability and provides for the unbounded, efficient scaling of blockchain computation.
You can create a 100% on-chain and scalable auction house for NFTs, or a decentralized exchange for tokens. Or a software library that helps others with the new way of coding DeFi. Or code that interacts with other blockchains.
More inspiration and starting points:
Decentralized exchanges based on order books or automated markets makers (AMMs)
Port your favorite DeFi project from a synchronous platform and explore the differences
Have a look at https://dappradar.com/defi to see a list of the most used DeFi apps in the web3 ecosystem
Prediction markets to harness collective intelligence
Links to get you started:
- Video tutorials with sample code: Basic DEX example, ICP transfer
- Token standards: Ledger Canister, DIP20, EXT, IS20, DFT, DRC
- Transaction history and asset provenance: CAP
- Bitcoin Integration: How it works, Wiki,
- Mock implementation of ECDSA signing in canisters
- Dieter Sommer’s post on World Computers and Real-World Computers for DeFi
- More tutorials: An introduction to the ICP Ledger, Handling ICP Payments (Rust)