diff --git a/vcsserver/base.py b/vcsserver/base.py
--- a/vcsserver/base.py
+++ b/vcsserver/base.py
@@ -64,7 +64,7 @@ def obfuscate_qs(query_string):
         parsed.append((k, v))
 
     return '&'.join('{}{}'.format(
-        k, '={}'.format(v) if v else '') for k, v in parsed)
+        k, f'={v}' if v else '') for k, v in parsed)
 
 
 def raise_from_original(new_type, org_exc: Exception):
diff --git a/vcsserver/exceptions.py b/vcsserver/exceptions.py
--- a/vcsserver/exceptions.py
+++ b/vcsserver/exceptions.py
@@ -109,7 +109,7 @@ class HTTPRepoLocked(HTTPLocked):
     def __init__(self, title, status_code=None, **kwargs):
         self.code = status_code or HTTPLocked.code
         self.title = title
-        super(HTTPRepoLocked, self).__init__(**kwargs)
+        super().__init__(**kwargs)
 
 
 class HTTPRepoBranchProtected(HTTPForbidden):
diff --git a/vcsserver/hooks.py b/vcsserver/hooks.py
--- a/vcsserver/hooks.py
+++ b/vcsserver/hooks.py
@@ -1,5 +1,3 @@
-# -*- coding: utf-8 -*-
-
 # RhodeCode VCSServer provides access to different vcs backends via network.
 # Copyright (C) 2014-2020 RhodeCode GmbH
 #
@@ -553,7 +551,7 @@ def git_pre_receive(unused_repo_path, re
         if type_ == 'heads' and not (new_branch or delete_branch):
             old_rev = push_ref['old_rev']
             new_rev = push_ref['new_rev']
-            cmd = [settings.GIT_EXECUTABLE, 'rev-list', old_rev, '^{}'.format(new_rev)]
+            cmd = [settings.GIT_EXECUTABLE, 'rev-list', old_rev, f'^{new_rev}']
             stdout, stderr = subprocessio.run_command(
                 cmd, env=os.environ.copy())
             # means we're having some non-reachable objects, this forced push was used
diff --git a/vcsserver/http_main.py b/vcsserver/http_main.py
--- a/vcsserver/http_main.py
+++ b/vcsserver/http_main.py
@@ -206,7 +206,7 @@ class VCSViewPredicate(object):
         self.remotes = val
 
     def text(self):
-        return 'vcs view method = %s' % (list(self.remotes.keys()),)
+        return f'vcs view method = {list(self.remotes.keys())}'
 
     phash = text
 
@@ -368,7 +368,7 @@ class HTTPApplication(object):
         if statsd:
             statsd.incr(
                 'vcsserver_method_total', tags=[
-                    "method:{}".format(method),
+                    f"method:{method}",
                 ])
         return payload, remote, method, args, kwargs
 
@@ -673,9 +673,9 @@ class HTTPApplication(object):
 
         statsd = request.registry.statsd
         if statsd:
-            exc_type = "{}.{}".format(exception.__class__.__module__, exception.__class__.__name__)
+            exc_type = f"{exception.__class__.__module__}.{exception.__class__.__name__}"
             statsd.incr('vcsserver_exception_total',
-                        tags=["type:{}".format(exc_type)])
+                        tags=[f"type:{exc_type}"])
         raise exception
 
 
diff --git a/vcsserver/lib/exc_tracking.py b/vcsserver/lib/exc_tracking.py
--- a/vcsserver/lib/exc_tracking.py
+++ b/vcsserver/lib/exc_tracking.py
@@ -1,5 +1,3 @@
-# -*- coding: utf-8 -*-
-
 # RhodeCode VCSServer provides access to different vcs backends via network.
 # Copyright (C) 2014-2020 RhodeCode GmbH
 #
@@ -126,10 +124,10 @@ def store_exception(exc_id, exc_info, pr
 def _find_exc_file(exc_id, prefix=global_prefix):
     exc_store_path = get_exc_store()
     if prefix:
-        exc_id = '{}_{}'.format(exc_id, prefix)
+        exc_id = f'{exc_id}_{prefix}'
     else:
         # search without a prefix
-        exc_id = '{}'.format(exc_id)
+        exc_id = f'{exc_id}'
 
     # we need to search the store for such start pattern as above
     for fname in os.listdir(exc_store_path):
diff --git a/vcsserver/lib/memory_lru_dict.py b/vcsserver/lib/memory_lru_dict.py
--- a/vcsserver/lib/memory_lru_dict.py
+++ b/vcsserver/lib/memory_lru_dict.py
@@ -1,5 +1,3 @@
-# -*- coding: utf-8 -*-
-
 # RhodeCode VCSServer provides access to different vcs backends via network.
 # Copyright (C) 2014-2020 RhodeCode GmbH
 #
@@ -53,11 +51,11 @@ class LRUDictDebug(LRUDict):
     Wrapper to provide some debug options
     """
     def _report_keys(self):
-        elems_cnt = '%s/%s' % (len(list(self.keys())), self.size)
+        elems_cnt = '{}/{}'.format(len(list(self.keys())), self.size)
         # trick for pformat print it more nicely
         fmt = '\n'
         for cnt, elem in enumerate(self.keys()):
-            fmt += '%s - %s\n' % (cnt+1, safe_str(elem))
+            fmt += '{} - {}\n'.format(cnt+1, safe_str(elem))
         log.debug('current LRU keys (%s):%s', elems_cnt, fmt)
 
     def __getitem__(self, key):
diff --git a/vcsserver/lib/rc_cache/__init__.py b/vcsserver/lib/rc_cache/__init__.py
--- a/vcsserver/lib/rc_cache/__init__.py
+++ b/vcsserver/lib/rc_cache/__init__.py
@@ -1,5 +1,3 @@
-# -*- coding: utf-8 -*-
-
 # RhodeCode VCSServer provides access to different vcs backends via network.
 # Copyright (C) 2014-2020 RhodeCode GmbH
 #
diff --git a/vcsserver/lib/rc_cache/backends.py b/vcsserver/lib/rc_cache/backends.py
--- a/vcsserver/lib/rc_cache/backends.py
+++ b/vcsserver/lib/rc_cache/backends.py
@@ -58,7 +58,7 @@ class LRUMemoryBackend(memory_backend.Me
             LRUDictClass = LRUDictDebug
 
         arguments['cache_dict'] = LRUDictClass(self.max_size)
-        super(LRUMemoryBackend, self).__init__(arguments)
+        super().__init__(arguments)
 
     def __repr__(self):
         return f'{self.__class__}(maxsize=`{self.max_size}`)'
@@ -79,19 +79,19 @@ class LRUMemoryBackend(memory_backend.Me
 
 
 class PickleSerializer:
-    serializer: Union[None, Serializer] = staticmethod(  # type: ignore
+    serializer: None | Serializer = staticmethod(  # type: ignore
         functools.partial(pickle.dumps, protocol=pickle.HIGHEST_PROTOCOL)
     )
-    deserializer: Union[None, Deserializer] = staticmethod(  # type: ignore
+    deserializer: None | Deserializer = staticmethod(  # type: ignore
         functools.partial(pickle.loads)
     )
 
 
 class MsgPackSerializer(object):
-    serializer: Union[None, Serializer] = staticmethod(  # type: ignore
+    serializer: None | Serializer = staticmethod(  # type: ignore
         msgpack.packb
     )
-    deserializer: Union[None, Deserializer] = staticmethod(  # type: ignore
+    deserializer: None | Deserializer = staticmethod(  # type: ignore
         functools.partial(msgpack.unpackb, use_list=False)
     )
 
@@ -114,7 +114,7 @@ class FileNamespaceBackend(PickleSeriali
             os.makedirs(db_file_dir)
 
         try:
-            super(FileNamespaceBackend, self).__init__(arguments)
+            super().__init__(arguments)
         except Exception:
             log.exception('Failed to initialize db at: %s', db_file)
             raise
@@ -152,7 +152,7 @@ class BaseRedisBackend(redis_backend.Red
 
     def __init__(self, arguments):
         self.db_conn = arguments.get('host', '') or arguments.get('url', '') or 'redis-host'
-        super(BaseRedisBackend, self).__init__(arguments)
+        super().__init__(arguments)
 
         self._lock_timeout = self.lock_timeout
         self._lock_auto_renewal = str2bool(arguments.pop("lock_auto_renewal", True))
diff --git a/vcsserver/lib/rc_cache/utils.py b/vcsserver/lib/rc_cache/utils.py
--- a/vcsserver/lib/rc_cache/utils.py
+++ b/vcsserver/lib/rc_cache/utils.py
@@ -168,7 +168,7 @@ def get_or_create_region(region_name, re
     region_obj = region_meta.dogpile_cache_regions.get(region_name)
     if not region_obj:
         reg_keys = list(region_meta.dogpile_cache_regions.keys())
-        raise EnvironmentError(f'Region `{region_name}` not in configured: {reg_keys}.')
+        raise OSError(f'Region `{region_name}` not in configured: {reg_keys}.')
 
     region_uid_name = f'{region_name}:{region_namespace}'
 
diff --git a/vcsserver/lib/request_counter.py b/vcsserver/lib/request_counter.py
--- a/vcsserver/lib/request_counter.py
+++ b/vcsserver/lib/request_counter.py
@@ -1,5 +1,3 @@
-# -*- coding: utf-8 -*-
-
 # RhodeCode VCSServer provides access to different vcs backends via network.
 # Copyright (C) 2014-2020 RhodeCode GmbH
 #
diff --git a/vcsserver/lib/statsd_client.py b/vcsserver/lib/statsd_client.py
--- a/vcsserver/lib/statsd_client.py
+++ b/vcsserver/lib/statsd_client.py
@@ -29,7 +29,7 @@ class _Singleton(type):
 
     def __call__(cls, *args, **kwargs):
         if cls not in cls._instances:
-            cls._instances[cls] = super(_Singleton, cls).__call__(*args, **kwargs)
+            cls._instances[cls] = super().__call__(*args, **kwargs)
         return cls._instances[cls]
 
 
@@ -47,13 +47,13 @@ class StatsdClientClass(Singleton):
 
         if name.startswith("statsd"):
             if self.setup_run:
-                return super(StatsdClientClass, self).__getattribute__(name)
+                return super().__getattribute__(name)
             else:
                 if self.strict_mode_init:
                     raise StatsdClientNotInitialised(f"requested key was {name}")
                 return None
 
-        return super(StatsdClientClass, self).__getattribute__(name)
+        return super().__getattribute__(name)
 
     def setup(self, settings):
         """
diff --git a/vcsserver/pygrack.py b/vcsserver/pygrack.py
--- a/vcsserver/pygrack.py
+++ b/vcsserver/pygrack.py
@@ -56,7 +56,7 @@ class FileWrapper(object):
         return data
 
     def __repr__(self):
-        return '<FileWrapper %s len: %s, read: %s>' % (
+        return '<FileWrapper {} len: {}, read: {}>'.format(
             self.fd, self.content_length, self.content_length - self.remain
         )
 
@@ -66,7 +66,7 @@ class GitRepository(object):
 
     git_folder_signature = frozenset(('config', 'head', 'info', 'objects', 'refs'))
     commands = frozenset(('git-upload-pack', 'git-receive-pack'))
-    valid_accepts = frozenset(('application/x-{}-result'.format(c) for c in commands))
+    valid_accepts = frozenset(f'application/x-{c}-result' for c in commands)
 
     # The last bytes are the SHA1 of the first 12 bytes.
     EMPTY_PACK = (
@@ -330,7 +330,7 @@ class GitRepository(object):
             inputstream = request.body_file_seekable
 
         resp = Response()
-        resp.content_type = 'application/x-{}-result'.format(git_command)
+        resp.content_type = f'application/x-{git_command}-result'
         resp.charset = None
 
         pre_pull_messages = ''
diff --git a/vcsserver/remote/git.py b/vcsserver/remote/git.py
--- a/vcsserver/remote/git.py
+++ b/vcsserver/remote/git.py
@@ -142,7 +142,7 @@ class GitRemote(RemoteBase):
 
     def _wire_to_config(self, wire):
         if 'config' in wire:
-            return dict([(x[0] + '_' + x[1], x[2]) for x in wire['config']])
+            return {x[0] + '_' + x[1]: x[2] for x in wire['config']}
         return {}
 
     def _remote_conf(self, config):
@@ -151,7 +151,7 @@ class GitRemote(RemoteBase):
         ]
         ssl_cert_dir = config.get('vcs_ssl_dir')
         if ssl_cert_dir:
-            params.extend(['-c', 'http.sslCAinfo={}'.format(ssl_cert_dir)])
+            params.extend(['-c', f'http.sslCAinfo={ssl_cert_dir}'])
         return params
 
     @reraise_safe_exceptions
@@ -321,7 +321,7 @@ class GitRemote(RemoteBase):
             store = LFSOidStore(
                 oid=oid, repo=repo_name, store_location=store_location)
             return store.oid_path
-        raise ValueError('Unable to fetch oid with path {}'.format(oid))
+        raise ValueError(f'Unable to fetch oid with path {oid}')
 
     @reraise_safe_exceptions
     def bulk_request(self, wire, rev, pre_load):
@@ -383,7 +383,7 @@ class GitRemote(RemoteBase):
 
         q = {"service": 'git-upload-pack'}
         qs = '?%s' % urllib.parse.urlencode(q)
-        cu = "%s%s" % (test_uri, qs)
+        cu = "{}{}".format(test_uri, qs)
         req = urllib.request.Request(cu, None, {})
 
         try:
@@ -394,7 +394,7 @@ class GitRemote(RemoteBase):
         except Exception as e:
             log.warning("URL cannot be opened: %s", cleaned_uri, exc_info=True)
             # means it cannot be cloned
-            raise exceptions.URLError(e)("[%s] org_exc: %s" % (cleaned_uri, e))
+            raise exceptions.URLError(e)("[{}] org_exc: {}".format(cleaned_uri, e))
 
         # now detect if it's proper git repo
         gitdata = resp.read()
@@ -405,7 +405,7 @@ class GitRemote(RemoteBase):
             pass
         else:
             raise exceptions.URLError()(
-                "url [%s] does not look like an git" % (cleaned_uri,))
+                "url [{}] does not look like an git".format(cleaned_uri))
 
         return True
 
@@ -943,12 +943,12 @@ class GitRemote(RemoteBase):
                     author = commit.get_object().author
 
                 if author.email:
-                    return "{} <{}>".format(author.name, author.email)
+                    return f"{author.name} <{author.email}>"
 
                 try:
-                    return "{}".format(author.name)
+                    return f"{author.name}"
                 except Exception:
-                    return "{}".format(safe_str(author.raw_name))
+                    return f"{safe_str(author.raw_name)}"
 
         return _author(repo_id, commit_id)
 
@@ -997,7 +997,7 @@ class GitRemote(RemoteBase):
                 wire, ['rev-list', '--all', '--children', f'{commit_id}^..{head}'])
 
             child_ids = []
-            pat = re.compile(r'^{}'.format(commit_id))
+            pat = re.compile(fr'^{commit_id}')
             for line in output.splitlines():
                 line = safe_str(line)
                 if pat.match(line):
@@ -1036,7 +1036,7 @@ class GitRemote(RemoteBase):
     def tag_remove(self, wire, tag_name):
         repo_init = self._factory.repo_libgit2(wire)
         with repo_init as repo:
-            key = 'refs/tags/{}'.format(tag_name)
+            key = f'refs/tags/{tag_name}'
             repo.references.delete(key)
 
     @reraise_safe_exceptions
@@ -1081,7 +1081,7 @@ class GitRemote(RemoteBase):
                 try:
                     tree = repo[tree_id]
                 except KeyError:
-                    raise ObjectMissing('No tree with id: {}'.format(tree_id))
+                    raise ObjectMissing(f'No tree with id: {tree_id}')
 
                 result = []
                 for item in tree:
@@ -1363,7 +1363,7 @@ class GitRemote(RemoteBase):
                     try:
                         tree = repo[tree_id]
                     except KeyError:
-                        raise ObjectMissing('No tree with id: {}'.format(tree_id))
+                        raise ObjectMissing(f'No tree with id: {tree_id}')
 
                 index = LibGit2Index.Index()
                 index.read_tree(tree)
diff --git a/vcsserver/remote/hg.py b/vcsserver/remote/hg.py
--- a/vcsserver/remote/hg.py
+++ b/vcsserver/remote/hg.py
@@ -431,9 +431,9 @@ class HgRemote(RemoteBase):
                         ('Accept', 'application/mercurial-0.1')]
 
         q = {"cmd": 'between'}
-        q.update({'pairs': "%s-%s" % ('0' * 40, '0' * 40)})
+        q.update({'pairs': "{}-{}".format('0' * 40, '0' * 40)})
         qs = '?%s' % urllib.parse.urlencode(q)
-        cu = "%s%s" % (test_uri, qs)
+        cu = "{}{}".format(test_uri, qs)
         req = urllib.request.Request(cu, None, {})
 
         try:
@@ -444,7 +444,7 @@ class HgRemote(RemoteBase):
         except Exception as e:
             log.warning("URL cannot be opened: %s", cleaned_uri, exc_info=True)
             # means it cannot be cloned
-            raise exceptions.URLError(e)("[%s] org_exc: %s" % (cleaned_uri, e))
+            raise exceptions.URLError(e)("[{}] org_exc: {}".format(cleaned_uri, e))
 
         # now check if it's a proper hg repo, but don't do it for svn
         try:
diff --git a/vcsserver/remote/svn.py b/vcsserver/remote/svn.py
--- a/vcsserver/remote/svn.py
+++ b/vcsserver/remote/svn.py
@@ -138,7 +138,7 @@ class SvnRemote(RemoteBase):
             tb = traceback.format_exc()
             log.debug("Invalid Subversion url: `%s`, tb: %s", url, tb)
             raise URLError(
-                '"%s" is not a valid Subversion source url.' % (url, ))
+                '"{}" is not a valid Subversion source url.'.format(url))
         return True
 
     def is_path_valid_repository(self, wire, path):
@@ -239,7 +239,7 @@ class SvnRemote(RemoteBase):
                 removed.append(path)
             else:
                 raise NotImplementedError(
-                    "Action %s not supported on path %s" % (
+                    "Action {} not supported on path {}".format(
                         change.action, path))
 
         changes = {
@@ -418,10 +418,10 @@ class SvnRemote(RemoteBase):
                 reason = 'INVALID_CERTIFICATE'
 
             if reason == 'UNKNOWN':
-                reason = 'UNKNOWN:{}'.format(safe_str(errors))
+                reason = f'UNKNOWN:{safe_str(errors)}'
 
             raise Exception(
-                'Failed to dump the remote repository from %s. Reason:%s' % (
+                'Failed to dump the remote repository from {}. Reason:{}'.format(
                     src_url, reason))
         if load.returncode != 0:
             raise Exception(
@@ -575,8 +575,7 @@ class SvnRemote(RemoteBase):
                     # return only DIR, and then all entries in that dir
                     yield os.path.join(root_dir, f_name), {'mode': filemode_default}, f_type
                     new_root = os.path.join(root_dir, f_name)
-                    for _f_name, _f_data, _f_type in walk_tree(root, new_root, _commit_id):
-                        yield _f_name, _f_data, _f_type
+                    yield from walk_tree(root, new_root, _commit_id)
                 else:
 
                     f_path = os.path.join(root_dir, f_name).rstrip(b'/')
@@ -723,10 +722,10 @@ class SvnDiffer(object):
             buf.write("=" * 67 + '\n')
             buf.write("Cannot display: file marked as a binary type.\n")
             buf.write("svn:mime-type = %s\n" % mime_type)
-        buf.write("Index: %s\n" % (tgt_path, ))
+        buf.write("Index: {}\n".format(tgt_path))
         buf.write("=" * 67 + '\n')
-        buf.write("diff --git a/%(tgt_path)s b/%(tgt_path)s\n" % {
-            'tgt_path': tgt_path})
+        buf.write("diff --git a/{tgt_path} b/{tgt_path}\n".format(
+            tgt_path=tgt_path))
 
         if change == 'add':
             # TODO: johbo: SVN is missing a zero here compared to git
@@ -746,15 +745,15 @@ class SvnDiffer(object):
             # if self.binary_content:
             #     buf.write('GIT binary patch\n')
 
-            buf.write("--- a/%s\t(revision %s)\n" % (
+            buf.write("--- a/{}\t(revision {})\n".format(
                 src_path, self.src_rev))
             src_lines = self._svn_readlines(self.src_root, src_full_path)
 
         if change == 'delete':
-            buf.write("+++ /dev/null\t(revision %s)\n" % (self.tgt_rev, ))
+            buf.write("+++ /dev/null\t(revision {})\n".format(self.tgt_rev))
             tgt_lines = []
         else:
-            buf.write("+++ b/%s\t(revision %s)\n" % (
+            buf.write("+++ b/{}\t(revision {})\n".format(
                 tgt_path, self.tgt_rev))
             tgt_lines = self._svn_readlines(self.tgt_root, tgt_full_path)
 
diff --git a/vcsserver/scm_app.py b/vcsserver/scm_app.py
--- a/vcsserver/scm_app.py
+++ b/vcsserver/scm_app.py
@@ -104,7 +104,7 @@ class HgWeb(mercurial.hgweb.hgweb_mod.hg
             res.setbodybytes(b'')
             return res.sendresponse()
 
-        return super(HgWeb, self)._runwsgi(req, res, repo)
+        return super()._runwsgi(req, res, repo)
 
 
 def make_hg_ui_from_config(repo_config):
diff --git a/vcsserver/str_utils.py b/vcsserver/str_utils.py
--- a/vcsserver/str_utils.py
+++ b/vcsserver/str_utils.py
@@ -44,7 +44,7 @@ def base64_to_str(text) -> str:
     return safe_str(base64.encodebytes(safe_bytes(text))).strip()
 
 
-def get_default_encodings() -> typing.List[str]:
+def get_default_encodings() -> list[str]:
     return ['utf8']
 
 
diff --git a/vcsserver/svn_diff.py b/vcsserver/svn_diff.py
--- a/vcsserver/svn_diff.py
+++ b/vcsserver/svn_diff.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 #
 # Copyright (C) 2004-2009 Edgewall Software
 # Copyright (C) 2004-2006 Christopher Lenz <cmlenz@gmx.de>
@@ -174,7 +173,7 @@ def unified_diff(fromlines, tolines, con
             i1, i2 = -1, -1  # support for Add changes
         if j1 == 0 and j2 == 0:
             j1, j2 = -1, -1  # support for Delete changes
-        yield '@@ -%s +%s @@%s' % (
+        yield '@@ -{} +{} @@{}'.format(
             _hunk_range(i1 + 1, i2 - i1),
             _hunk_range(j1 + 1, j2 - j1),
             lineterm)
diff --git a/vcsserver/utils.py b/vcsserver/utils.py
--- a/vcsserver/utils.py
+++ b/vcsserver/utils.py
@@ -41,7 +41,7 @@ class StrictAttributeDict(AttributeDictB
         try:
             return self[attr]
         except KeyError:
-            raise AttributeError('%s object has no attribute %s' % (
+            raise AttributeError('{} object has no attribute {}'.format(
                 self.__class__, attr))
 
 
diff --git a/vcsserver/vcs_base.py b/vcsserver/vcs_base.py
--- a/vcsserver/vcs_base.py
+++ b/vcsserver/vcs_base.py
@@ -28,7 +28,7 @@ class RemoteBase(object):
 
     def _cache_on(self, wire):
         context = wire.get('context', '')
-        context_uid = '{}'.format(context)
+        context_uid = f'{context}'
         repo_id = wire.get('repo_id', '')
         cache = wire.get('cache', True)
         cache_on = context and cache