The problem DeFi Application solves

In centralized applications the web browser calls to the front part of website and it access backend but it doesn't works in the system like banks and crypto wallets, because in this anyone who has the access to handle backend can steal your money, where in the DeFi app instead of accessing to backend servers website talks directly to the blockchain, blockchain contains the smart contracts and these smart contracts are immutable programs, so codes cannot be changed, and all the data stored in public ledger which is also immutable and when we add new data to blockchain it will be publically verifiable.

Challenges I ran into

i was struggleing with the process of compilation in project i have two migration file one is for add data into the blockchain and the another one to deploy them to the server.., while i use truffle compile it shows some packages are missing and i have fixed them all with the help of internet and some experts.