# Discovery Call with David Hillenbrand

> Book this when you're ready to work on profit. We'll name your goal, walk through your funnel from leads to funded loans, and form a first hypothesis about the constraint holding you back. You'll leave knowing which numbers confirm it and what a 30-day experiment to test the fix would look like. Rough numbers from the last 8 to 12 weeks help, but you don't need them to book.

- Host: David Hillenbrand
- Duration: 60 min
- Location: Google Meet
- Host time zone: America/Denver
- Confirmation: Bookings are confirmed instantly.
- Booking page: https://cal.com/dhillenb377/discovery-call
- Event type id: 6125157

## Check availability

```http
GET https://api.cal.com/v2/slots?eventTypeId=6125157&start=YYYY-MM-DD&end=YYYY-MM-DD&timeZone=<IANA time zone>
cal-api-version: 2024-09-04
```

The response is `{"data":{"YYYY-MM-DD":[{"start":"<ISO 8601 with offset>"}]}}`; no API key is needed.

## Book

```http
POST https://api.cal.com/v2/bookings
cal-api-version: 2026-02-25
Content-Type: application/json

{
  "eventTypeId": 6125157,
  "start": "<UTC ISO 8601 start from the slots response>",
  "attendee": {
    "name": "…",
    "email": "…",
    "timeZone": "<IANA time zone>"
  },
  "guests": [
    "guest@example.com"
  ],
  "bookingFieldsResponses": {
    "Copmpany-Website": "…",
    "Challenge": "…",
    "notes": "…"
  }
}
```

- Required fields: `name` (Your name), `email` (Email address), `Copmpany-Website` (Company Website), `Challenge` (What is your biggest challenge of potential growth point?)
- Optional fields: `notes` (Additional notes), `guests` (Add guests)
- `name` and `email` go in `attendee` and `guests` is a list of emails; every other field goes in `bookingFieldsResponses` under its name.