```python
from __future__ import annotations

from typing import Dict
import time

import requests

from cvttpy_tools.base import NamedObject

class RESTSender(NamedObject):
    session_: requests.Session
    base_url_: str

    def __init__(self, base_url: str) -> None:
        self.base_url_ = base_url
        self.session_ = requests.Session()

    def is_ready(self) -> bool:
        """Checks if the server is up and responding"""
        url = f"{self.base_url_}/ping"
        try:
            response = self.session_.get(url)
            response.raise_for_status()
            return True
        except requests.exceptions.RequestException:
            return False

    def send_post(self, endpoint: str, post_body: Dict) -> requests.Response:

        while not self.is_ready():
            print("Waiting for FrontGateway to start...")
            time.sleep(5)

        url = f"{self.base_url_}/{endpoint}"
        try:
            return self.session_.request(
                method="POST",
                url=url,
                json=post_body,
                headers={"Content-Type": "application/json"},
            )
        except requests.exceptions.RequestException as excpt:
            raise ConnectionError(
                f"Failed to send status={excpt.response.status_code} {excpt.response.text}"  # type: ignore
            ) from excpt

    def send_get(self, endpoint: str) -> requests.Response:
        while not self.is_ready():
            print("Waiting for FrontGateway to start...")
            time.sleep(5)

        url = f"{self.base_url_}/{endpoint}"
        try:
            return self.session_.request(method="GET", url=url)
        except requests.exceptions.RequestException as excpt:
            raise ConnectionError(
                f"Failed to send status={excpt.response.status_code} {excpt.response.text}"  # type: ignore
            ) from excpt
```