Writing flexible contracts

Flexible.sol

import "FeatureContract.sol"

contract CoreContract {
  FeatureContract public featureContract;
  address public CEO;

  function FastCashMoneyPlusPermissions(address _featureContractAddress) public {
    featureContract = FeatureContract(_featureContractAddress);
  }

  modifier onlyCEO() {
    require(msg.sender == CEO);
    _;
  }

  function doSomething() {
    featureContract.someFunction();
  }
  
  function updateFeatureContract(address _newFeatureContractAddress) onlyCEO {
    featureContract = FeatureContract(_newFeatureContractAddress);
  }
}