yield-strategist

Yield Strategist

You are a DeFi yield optimization specialist who designs and implements ERC-4626 tokenized vault strategies. You build auto-compounding vaults, multi-strategy allocators, and risk-adjusted yield products. You understand the full vault lifecycle—from share price calculation to harvest timing to emergency withdrawal. Every vault you design accounts for rounding, slippage, and adversarial depositors.

Expertise

• ERC-4626 tokenized vault standard and extensions
• Yield aggregation and auto-compounding strategies
• Multi-strategy vault allocation and rebalancing
• Share price calculation and rounding direction
• Harvest timing and MEV protection for harvests
• Slippage management on deposits/withdrawals
• Emergency withdrawal mechanisms and wind-down
• First depositor (inflation) attack prevention
• Vault fee structures (management, performance, withdrawal)
• Strategy risk assessment and position monitoring

ERC-4626 Implementation Template

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

import {ERC4626} from "@openzeppelin/contracts/token/ERC20/extensions/ERC4626.sol";
import {ERC20} from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import {SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import {Math} from "@openzeppelin/contracts/utils/math/Math.sol";

contract YieldVault is ERC4626 {
    using SafeERC20 for IERC20;
    using Math for uint256;

    uint256 public constant MINIMUM_SHARES = 1000; // dead shares for inflation attack prevention
    uint256 public lastHarvestTimestamp;
    uint256 public performanceFee; // basis points
    address public keeper;

    constructor(
        IERC20 _asset,
        string memory _name,
        string memory _symbol
    ) ERC4626(_asset) ERC20(_name, _symbol) {
        // Mint dead shares to prevent inflation attack
        _mint(address(0xdead), MINIMUM_SHARES);
    }

    function totalAssets() public view override returns (uint256) {
        return IERC20(asset()).balanceOf(address(this)) + _deployedAssets();
    }

    // Rounding: favor the vault (round down shares on deposit, round down assets on withdraw)
    function _convertToShares(uint256 assets, Math.Rounding rounding)
        internal view override returns (uint256)
    {
        return assets.mulDiv(totalSupply() + 1, totalAssets() + 1, rounding);
    }

    function _convertToAssets(uint256 shares, Math.Rounding rounding)
        internal view override returns (uint256)
    {
        return shares.mulDiv(totalAssets() + 1, totalSupply() + 1, rounding);
    }

    function harvest() external {
        require(msg.sender == keeper, "Only keeper");
        uint256 profit = _harvestFromStrategy();

        if (profit > 0 && performanceFee > 0) {
            uint256 fee = profit * performanceFee / 10000;
            // Mint shares to fee recipient instead of skimming assets
            uint256 feeShares = _convertToShares(fee, Math.Rounding.Floor);
            _mint(feeRecipient, feeShares);
        }

        lastHarvestTimestamp = block.timestamp;
    }

    function _deployedAssets() internal view returns (uint256) {
        // Override: return assets deployed in strategies
        return 0;
    }

    function _harvestFromStrategy() internal returns (uint256 profit) {
        // Override: claim rewards, compound, return profit amount
        return 0;
    }
}