diff --git a/python_coderunner/src/command_builder/interpolator_command_builder.py b/python_coderunner/src/command_builder/interpolator_command_builder.py
index 4843bef..84e08c2 100644
--- a/python_coderunner/src/command_builder/interpolator_command_builder.py
+++ b/python_coderunner/src/command_builder/interpolator_command_builder.py
@@ -7,14 +7,14 @@
 
 
 class TInterpolatorCommandBuilder(ICommandBuilder):
-    WORKSPACE_ROOT_PATTERN: ClassVar[re.Pattern[str]] = re.compile(r"\$workspaceRoot")
-    FULL_FILE_NAME_PATTERN: ClassVar[re.Pattern[str]] = re.compile(r"\$fullFileName")
-    FILE_NAME_WITHOUT_EXT_PATTERN: ClassVar[re.Pattern[str]] = re.compile(r"\$fileNameWithoutExt")
-    FILE_NAME_PATTERN: ClassVar[re.Pattern[str]] = re.compile(r"\$fileName")
-    FILE_EXT: ClassVar[re.Pattern[str]] = re.compile(r"\$fileExt")
-    DRIVE_LETTER_PATTERN: ClassVar[re.Pattern[str]] = re.compile(r"\$driveLetter")
-    DIR_WITHOUT_TRAILING_SLASH_PATTERN: ClassVar[re.Pattern[str]] = re.compile(r"\$dirWithoutTrailingSlash")
-    DIR_PATTERN: ClassVar[re.Pattern[str]] = re.compile(r"\$dir")
+    _WORKSPACE_ROOT_PATTERN: ClassVar[re.Pattern[str]] = re.compile(r"\$workspaceRoot")
+    _FULL_FILE_NAME_PATTERN: ClassVar[re.Pattern[str]] = re.compile(r"\$fullFileName")
+    _FILE_NAME_WITHOUT_EXT_PATTERN: ClassVar[re.Pattern[str]] = re.compile(r"\$fileNameWithoutExt")
+    _FILE_NAME_PATTERN: ClassVar[re.Pattern[str]] = re.compile(r"\$fileName")
+    _FILE_EXT: ClassVar[re.Pattern[str]] = re.compile(r"\$fileExt")
+    _DRIVE_LETTER_PATTERN: ClassVar[re.Pattern[str]] = re.compile(r"\$driveLetter")
+    _DIR_WITHOUT_TRAILING_SLASH_PATTERN: ClassVar[re.Pattern[str]] = re.compile(r"\$dirWithoutTrailingSlash")
+    _DIR_PATTERN: ClassVar[re.Pattern[str]] = re.compile(r"\$dir")
 
     def __init__(
         self,
@@ -34,23 +34,23 @@ def _interpolate(self, file_path_abs: str) -> str:
         The reverse alphabetical order is important so that substitutions are performed greedily,
         i.e. $dirWithoutTrailingSlash must be before $dir.
         """
-        interpolated_str: str = self.WORKSPACE_ROOT_PATTERN.sub(
+        interpolated_str: str = self._WORKSPACE_ROOT_PATTERN.sub(
             self._project_info_extractor.get_workspace_root(), self._template_string
         )
-        interpolated_str = self.FULL_FILE_NAME_PATTERN.sub(file_path_abs, interpolated_str)
-        interpolated_str = self.FILE_NAME_WITHOUT_EXT_PATTERN.sub(
+        interpolated_str = self._FULL_FILE_NAME_PATTERN.sub(file_path_abs, interpolated_str)
+        interpolated_str = self._FILE_NAME_WITHOUT_EXT_PATTERN.sub(
             self._file_info_extractor.get_file_name_without_ext(file_path_abs), interpolated_str
         )
-        interpolated_str = self.FILE_NAME_PATTERN.sub(
+        interpolated_str = self._FILE_NAME_PATTERN.sub(
             self._file_info_extractor.get_file_name(file_path_abs), interpolated_str
         )
-        interpolated_str = self.FILE_EXT.sub(self._file_info_extractor.get_file_ext(file_path_abs), interpolated_str)
-        interpolated_str = self.DRIVE_LETTER_PATTERN.sub(
+        interpolated_str = self._FILE_EXT.sub(self._file_info_extractor.get_file_ext(file_path_abs), interpolated_str)
+        interpolated_str = self._DRIVE_LETTER_PATTERN.sub(
             self._file_info_extractor.get_drive_letter(file_path_abs), interpolated_str
         )
-        interpolated_str = self.DIR_WITHOUT_TRAILING_SLASH_PATTERN.sub(
+        interpolated_str = self._DIR_WITHOUT_TRAILING_SLASH_PATTERN.sub(
             self._file_info_extractor.get_dir_without_trailing_slash(file_path_abs), interpolated_str
         )
-        interpolated_str = self.DIR_PATTERN.sub(self._file_info_extractor.get_dir(file_path_abs), interpolated_str)
+        interpolated_str = self._DIR_PATTERN.sub(self._file_info_extractor.get_dir(file_path_abs), interpolated_str)
 
         return interpolated_str
diff --git a/python_coderunner/src/config/config_field.py b/python_coderunner/src/config/config_field.py
index 2aa73d0..7a8c808 100644
--- a/python_coderunner/src/config/config_field.py
+++ b/python_coderunner/src/config/config_field.py
@@ -32,9 +32,11 @@ def get(self) -> ValueType:
         try:
             raw_value: Any = self._getter()
         except UndefinedValueError as e:
-            raise ConfigFieldUndefinedValueError.from_undefined_value_error(e, self._allowed_values_description)
+            raise ConfigFieldUndefinedValueError.from_undefined_value_error(e, self._allowed_values_description) from e
 
         try:
             return self._validator(raw_value)
         except ValidationError as e:
-            raise ConfigFieldValidationError.from_validation_error(e, self._name, self._allowed_values_description)
+            raise ConfigFieldValidationError.from_validation_error(
+                e, self._name, self._allowed_values_description
+            ) from e
diff --git a/python_coderunner/src/config/getter/interface.py b/python_coderunner/src/config/getter/interface.py
index 8456121..92f6b87 100644
--- a/python_coderunner/src/config/getter/interface.py
+++ b/python_coderunner/src/config/getter/interface.py
@@ -1,3 +1,14 @@
-from typing import Any, Callable, TypeAlias
+from abc import ABC, abstractmethod
+from typing import Any
 
-IConfigValueGetter: TypeAlias = Callable[[], Any]
+
+class IConfigValueGetter(ABC):
+    @abstractmethod
+    def __call__(self) -> Any:
+        """
+        Gets config value from external source.
+
+        Raises:
+            UndefinedValueError: If the config value is not defined.
+        """
+        raise NotImplementedError
diff --git a/python_coderunner/src/config/getter/vim_config_value_getter.py b/python_coderunner/src/config/getter/vim_config_value_getter.py
index 4f4a95c..3391ef5 100644
--- a/python_coderunner/src/config/getter/vim_config_value_getter.py
+++ b/python_coderunner/src/config/getter/vim_config_value_getter.py
@@ -3,9 +3,10 @@
 import vim
 
 from .exceptions import UndefinedValueError
+from .interface import IConfigValueGetter
 
 
-class TBaseVimConfigValueGetter:
+class TBaseVimConfigValueGetter(IConfigValueGetter):
     """Base class for getting Vim config values"""
 
     def _get_vim_var(self, var_name: str) -> Any:
diff --git a/python_coderunner/src/config/interface.py b/python_coderunner/src/config/interface.py
index 2015e00..c931af9 100644
--- a/python_coderunner/src/config/interface.py
+++ b/python_coderunner/src/config/interface.py
@@ -9,8 +9,6 @@ class EDispatchersTypes(StrEnum):
 
 
 class IConfig(ABC):
-    """Configuration interface"""
-
     @abstractmethod
     def get_by_file_ext(self) -> dict[str, str]:
         """Gets config for file extension-based dispatching"""
diff --git a/python_coderunner/src/config/validator/interface.py b/python_coderunner/src/config/validator/interface.py
index e30e4ef..534e0e5 100644
--- a/python_coderunner/src/config/validator/interface.py
+++ b/python_coderunner/src/config/validator/interface.py
@@ -9,6 +9,8 @@ class IValidator(ABC, Generic[ValueType]):
     def __call__(self, value: Any) -> ValueType:
         """
         Validates value and returns typed result.
-        Raises ValidationError on validation failure.
+
+        Raises:
+            ValidationError on validation failure.
         """
         raise NotImplementedError