diff --git a/lemur/plugins/lemur_acme/ultradns.py b/lemur/plugins/lemur_acme/ultradns.py
index 40661740..dcf3e3c6 100644
--- a/lemur/plugins/lemur_acme/ultradns.py
+++ b/lemur/plugins/lemur_acme/ultradns.py
@@ -91,7 +91,7 @@ def get_ultradns_token():
         "password": current_app.config.get("ACME_ULTRADNS_PASSWORD", ""),
     }
     base_uri = current_app.config.get("ACME_ULTRADNS_DOMAIN", "")
-    resp = requests.post("{0}{1}".format(base_uri, path), data=data, verify=True)
+    resp = requests.post(f"{base_uri}{path}", data=data, verify=True)
     return resp.json()["access_token"]
 
 
@@ -102,7 +102,7 @@ def _generate_header():
     Contains the Authorization access_key obtained from the get_ultradns_token() function.
     """
     access_token = get_ultradns_token()
-    return {"Authorization": "Bearer {}".format(access_token), "Content-Type": "application/json"}
+    return {"Authorization": f"Bearer {access_token}", "Content-Type": "application/json"}
 
 
 def _paginate(path, key):
@@ -120,7 +120,7 @@ def _get(path, params=None):
     """Function to execute a GET request on the given URL (base_uri + path) with given params"""
     base_uri = current_app.config.get("ACME_ULTRADNS_DOMAIN", "")
     resp = requests.get(
-        "{0}{1}".format(base_uri, path),
+        f"{base_uri}{path}",
         headers=_generate_header(),
         params=params,
         verify=True,
@@ -133,7 +133,7 @@ def _delete(path):
     """Function to execute a DELETE request on the given URL"""
     base_uri = current_app.config.get("ACME_ULTRADNS_DOMAIN", "")
     resp = requests.delete(
-        "{0}{1}".format(base_uri, path),
+        f"{base_uri}{path}",
         headers=_generate_header(),
         verify=True,
     )
@@ -144,7 +144,7 @@ def _post(path, params):
     """Executes a POST request on given URL. Body is sent in JSON format"""
     base_uri = current_app.config.get("ACME_ULTRADNS_DOMAIN", "")
     resp = requests.post(
-        "{0}{1}".format(base_uri, path),
+        f"{base_uri}{path}",
         headers=_generate_header(),
         data=json.dumps(params),
         verify=True,
@@ -168,13 +168,13 @@ def _has_dns_propagated(name, token, domain):
                 txt_records.append(txt_record.decode("utf-8"))
     except dns.exception.DNSException:
         function = sys._getframe().f_code.co_name
-        metrics.send("{}.fail".format(function), "counter", 1)
+        metrics.send(f"{function}.fail", "counter", 1)
         return False
 
     for txt_record in txt_records:
         if txt_record == token:
             function = sys._getframe().f_code.co_name
-            metrics.send("{}.success".format(function), "counter", 1)
+            metrics.send(f"{function}.success", "counter", 1)
             return True
 
     return False
@@ -216,11 +216,11 @@ def wait_for_dns_change(change_id, account_number=None):
             }
             current_app.logger.debug(log_data)
             if status:
-                metrics.send("{}.success".format(function), "counter", 1)
+                metrics.send(f"{function}.success", "counter", 1)
                 break
             time.sleep(10)
     if not status:
-        metrics.send("{}.fail".format, "counter", 1, metric_tags={"fqdn": fqdn, "txt_record": token})
+        metrics.send(f"{function}.fail", "counter", 1, metric_tags={"fqdn": fqdn, "txt_record": token})
         sentry.captureException(extra={"fqdn": str(fqdn), "txt_record": str(token)})
     return
 
@@ -253,8 +253,8 @@ def get_zone_name(domain, account_number):
                 zone_name = z
     if not zone_name:
         function = sys._getframe().f_code.co_name
-        metrics.send("{}.fail".format(function), "counter", 1)
-        raise Exception("No UltraDNS zone found for domain: {}".format(domain))
+        metrics.send(f"{function}.fail", "counter", 1)
+        raise Exception(f"No UltraDNS zone found for domain: {domain}")
     return zone_name
 
 
@@ -274,12 +274,12 @@ def create_txt_record(domain, token, account_number):
     zone_name = get_zone_name(domain, account_number)
     zone_parts = len(zone_name.split("."))
     node_name = ".".join(domain.split(".")[:-zone_parts])
-    fqdn = "{0}.{1}".format(node_name, zone_name)
-    path = "/v2/zones/{0}/rrsets/TXT/{1}".format(zone_name, node_name)
+    fqdn = f"{node_name}.{zone_name}"
+    path = f"/v2/zones/{zone_name}/rrsets/TXT/{node_name}"
     params = {
         "ttl": 5,
         "rdata": [
-            "{}".format(token)
+            f"{token}"
         ],
     }
 
@@ -334,19 +334,19 @@ def delete_txt_record(change_id, account_number, domain, token):
     zone_name = get_zone_name(domain, account_number)
     zone_parts = len(zone_name.split("."))
     node_name = ".".join(domain.split(".")[:-zone_parts])
-    path = "/v2/zones/{}/rrsets/16/{}".format(zone_name, node_name)
+    path = f"/v2/zones/{zone_name}/rrsets/16/{node_name}"
 
     try:
         rrsets = _get(path)
         record = Record(rrsets)
     except Exception as e:
         function = sys._getframe().f_code.co_name
-        metrics.send("{}.geterror".format(function), "counter", 1)
+        metrics.send(f"{function}.geterror", "counter", 1)
         # No Text Records remain or host is not in the zone anymore because all records have been deleted.
         return
     try:
         # Remove the record from the RRSet locally
-        record.rdata.remove("{}".format(token))
+        record.rdata.remove(f"{token}")
     except ValueError:
         function = sys._getframe().f_code.co_name
         log_data = {
@@ -394,7 +394,7 @@ def delete_acme_txt_records(domain):
     zone_name = get_zone_name(domain)
     zone_parts = len(zone_name.split("."))
     node_name = ".".join(domain.split(".")[:-zone_parts])
-    path = "/v2/zones/{}/rrsets/16/{}".format(zone_name, node_name)
+    path = f"/v2/zones/{zone_name}/rrsets/16/{node_name}"
 
     _delete(path)
 
@@ -420,7 +420,7 @@ def get_authoritative_nameserver(domain):
         rcode = response.rcode()
         if rcode != dns.rcode.NOERROR:
             function = sys._getframe().f_code.co_name
-            metrics.send("{}.error".format(function), "counter", 1)
+            metrics.send(f"{function}.error", "counter", 1)
             if rcode == dns.rcode.NXDOMAIN:
                 raise Exception("%s does not exist." % sub)
             else: