, A]
```
]

---
# Custom error type ala Monix BIO or ZIO

<br>

.eighty-two-left[
```scala
trait IO[`E`, A]
```
]

---
# Custom error type ala Monix BIO or ZIO

<br>

.eighty-two-left[
```scala
trait IO[E, `A`]
```
]

---
# Custom error type ala Monix BIO or ZIO

<br>

.eighty-two-left[
```scala
trait IO[E, A]
```

<br>

```scala
def fetchUser(id: UserId): IO[`UserNotFoundError`, User]
```
]

---
# Custom error type ala Monix BIO or ZIO

<br>

.eighty-two-left[
```scala
trait IO[E, A]

type Task[A] = `IO[Th