DApps & Smart Contracts Deep Dive
What Are Dapps
How decentralized apps are built, secured, and governed.
In this lesson
- How composability powers DeFi
- Where a dApp's trust comes from
Key takeaways
- 1Contracts plug into each other like 'money legos'
- 2Trust comes from open, verifiable code
- 3Composability multiplies both innovation and risk
Lesson summary
Composability lets smart contracts connect like building blocks.
Mental model
What Are Dapps in plain terms
Composability lets smart contracts connect like building blocks. It makes DeFi fast to innovate, but it also means one dependency can affect many products at once.
- How composability powers DeFi
- Where a dApp's trust comes from
Mechanics
How to reason about dapps
A dApp can call another protocol for swaps, prices, lending, or yield.
Developers build faster by reusing open contracts.
Risk compounds when several protocols depend on the same oracle, bridge, or liquidity source.
- Contracts plug into each other like 'money legos'
- Trust comes from open, verifiable code
- Composability multiplies both innovation and risk
Example
A concrete dapps example
A yield vault may deposit into a lending protocol, hedge on a DEX, and read prices from an oracle. The vault is only as resilient as those dependencies.
Common mistakes
Where people slip up with dapps
Users often judge only the app they see, not the full stack it touches or the contracts that can fail underneath it.
Risk notes
Risk checks for dapps
Composability can transmit failures through contracts, oracles, governance changes, and liquidity shocks.
- Identify at least two dependencies.
- Check whether contracts are upgradeable.
- Understand what happens if one dependency fails.
Practice
Make dapps stick
- Identify at least two dependencies.
- Check whether contracts are upgradeable.
- Understand what happens if one dependency fails.
Review
Key terms
- DApp
- Decentralized Application — software whose backend logic runs on a blockchain via smart contracts.
- DeFi
- Decentralized Finance — permissionless, composable financial services built on smart contracts.
- Liquidity
- How easily an asset can be bought or sold without moving its price much.
- Oracle
- A service that feeds real-world data (like prices) to smart contracts on-chain.
- Bridge
- Infrastructure that moves assets or data between blockchains.
Source notes
Editorial references
These references are starting points for verifying the mechanisms, risk checks, and product context behind this lesson.
Before you continue
Can you do these?
- Identify at least two dependencies.
- Check whether contracts are upgradeable.
- Understand what happens if one dependency fails.
Related learning
Keep reading
Checkpoint
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Pass the check to save progress, then continue through the track in order.
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Answer every question correctly to complete the lesson.
Composability in DeFi means…