diff --git a/tap_salesforce/salesforce/credentials.py b/tap_salesforce/salesforce/credentials.py
index dd80344..64e8213 100644
--- a/tap_salesforce/salesforce/credentials.py
+++ b/tap_salesforce/salesforce/credentials.py
@@ -1,107 +1,57 @@
 import threading
 import logging
 import requests
+import backoff
 from collections import namedtuple
 from simple_salesforce import SalesforceLogin
 
+from tap_salesforce.salesforce.exceptions import RetriableSalesforceAuthenticationError
 
 LOGGER = logging.getLogger(__name__)
 
-
-OAuthCredentials = namedtuple('OAuthCredentials', (
-    "client_id",
-    "client_secret",
-    "refresh_token"
-))
-
-PasswordCredentials = namedtuple('PasswordCredentials', (
-    "username",
-    "password",
-    "security_token"
-))
-
-
-def parse_credentials(config):
-    for cls in reversed((OAuthCredentials, PasswordCredentials)):
-        creds = cls(*(config.get(key) for key in cls._fields))
-        if all(creds):
-            return creds
-
-    raise Exception("Cannot create credentials from config.")
-
-
-class SalesforceAuth():
-    def __init__(self, credentials, is_sandbox=False):
-        self.is_sandbox = is_sandbox
-        self._credentials = credentials
-        self._access_token = None
-        self._instance_url = None
-        self._auth_header = None
-        self.login_timer = None
-
-    def login(self):
-        """Attempt to login and set the `instance_url` and `access_token` on success."""
-        pass
-
-    @property
-    def rest_headers(self):
-        return {"Authorization": "Bearer {}".format(self._access_token)}
-
-    @property
-    def bulk_headers(self):
-        return {"X-SFDC-Session": self._access_token,
-                "Content-Type": "application/json"}
-
-    @property
-    def instance_url(self):
-        return self._instance_url
-
-    @classmethod
-    def from_credentials(cls, credentials, **kwargs):
-        if isinstance(credentials, OAuthCredentials):
-            return SalesforceAuthOAuth(credentials, **kwargs)
-
-        if isinstance(credentials, PasswordCredentials):
-            return SalesforceAuthPassword(credentials, **kwargs)
-
-        raise Exception("Invalid credentials")
-
-
-class SalesforceAuthOAuth(SalesforceAuth):
     # The minimum expiration setting for SF Refresh Tokens is 15 minutes
     REFRESH_TOKEN_EXPIRATION_PERIOD = 900
 
+    # Errors that can be retried
+    RETRIABLE_SALESFORCE_RESPONSES = [
+        {'error': 'invalid_grant', 'error_description': 'expired authorization code'}
+    ]
+
     @property
     def _login_body(self):
         return {'grant_type': 'refresh_token', **self._credentials._asdict()}
 
-    @property
-    def _login_url(self):
-        login_url = 'https://login.salesforce.com/services/oauth2/token'
-
-        if self.is_sandbox:
-            login_url = 'https://test.salesforce.com/services/oauth2/token'
-
         return login_url
 
+    @backoff.on_exception(
+        backoff.expo,
+        RetriableSalesforceAuthenticationError,
+        max_tries=5,
+        factor=4,
+        jitter=None
+    )
     def login(self):
+        resp = None  # Ensure resp is defined outside the try block
         try:
-            LOGGER.info("Attempting login via OAuth2")
-
-            resp = requests.post(self._login_url,
-                                 data=self._login_body,
-                                 headers={"Content-Type": "application/x-www-form-urlencoded"})
-
-            resp.raise_for_status()
-            auth = resp.json()
-
             LOGGER.info("OAuth2 login successful")
             self._access_token = auth['access_token']
             self._instance_url = auth['instance_url']
+
+            LOGGER.info("Starting new login timer")
+            self.login_timer = threading.Timer(self.REFRESH_TOKEN_EXPIRATION_PERIOD, self.login)
+            self.login_timer.start()
+        except requests.exceptions.HTTPError as e:
+            error_message = f"{e}, Response from Salesforce: {resp.text}"
+            failed_auth_response = resp.json()
+            if failed_auth_response in self.RETRIABLE_SALESFORCE_RESPONSES:
+                raise RetriableSalesforceAuthenticationError(error_message) from e
+            else:
+                raise Exception(error_message) from e
         except Exception as e:
             error_message = str(e)
-            if resp:
-                error_message = error_message + ", Response from Salesforce: {}".format(resp.text)
+            if resp is not None:
+                # Ensure we capture the response body even when an error occurs
+                error_message += ", Response from Salesforce: {}".format(resp.text)
             raise Exception(error_message) from e
         finally:
             LOGGER.info("Starting new login timer")
@@ -110,11 +60,17 @@ def login(self):
 
 
 class SalesforceAuthPassword(SalesforceAuth):
-    def login(self):
-        login = SalesforceLogin(
-            sandbox=self.is_sandbox,
-            **self._credentials._asdict()
-        )
 
         self._access_token, host = login
         self._instance_url = "https://" + host
+
+if __name__ == "__main__":
+    sfdc_auth = SalesforceAuth.from_credentials(
+        is_sandbox=False,
+        credentials= parse_credentials({
+            "client_id": "secret_client_id",
+            "client_secret": "secret_client_secret",
+            "refresh_token": "abc123",
+        }),
+    )
+    sfdc_auth.login()
diff --git a/tap_salesforce/salesforce/exceptions.py b/tap_salesforce/salesforce/exceptions.py
index bd333ff..60c790c 100644
--- a/tap_salesforce/salesforce/exceptions.py
+++ b/tap_salesforce/salesforce/exceptions.py
@@ -20,3 +20,14 @@ class SFDCCustomNotAcceptableError(Exception):
     requests.exceptions.HTTPError: 406 Client Error: CustomNotAcceptable for 
     url: https://XXX.salesforce.com/services/data/v53.0/sobjects/XXX/describe
     """
+
+class RetriableSalesforceAuthenticationError(Exception):
+    """
+    A general classification for SFDC HTTP Authentication Errors.
+
+    The class is used to identify cases in which authentication should be
+    retried. It is primarily setup to handle simultaneous token requests during
+    the refresh token flow which returns the 400 Bad Request response. However,
+    it could be further expanded to handle other authentication errors that
+    could require retries.
+    """