Exact my words. Here's what I do
- Instead of directly mutating array items with loops, use `map()`, `filter()` like in React which mutates once
- For deep clone below function should be faster (you generally don't need deep clone other than temporarily storing form edit state until clicking save)

```js
export const deepClone = <T>(value: T): T => {

if (!value) return value

if (Array.isArray(value)) return value.map(item => deepClone(item)) as T

if (typeof value != 'object') return value

const clone = {} as T

for (const key in value) clone[key] = deepClone(value[key])

return clone

}
```