diff --git a/doc/requirements.txt b/doc/requirements.txt
index 4d20cfbb48..289105e5c1 100644
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -3,3 +3,4 @@ sphinx-reredirects<1
 towncrier~=23.6
 furo==2023.5.20
 -e .
+astroid @ git+https://github.com/pylint-dev/astroid.git@cf8763a2b8e897ec7c8389906f3cb13714300cd2
diff --git a/doc/whatsnew/fragments/529.performance b/doc/whatsnew/fragments/529.performance
new file mode 100644
index 0000000000..69f4a4f1d8
--- /dev/null
+++ b/doc/whatsnew/fragments/529.performance
@@ -0,0 +1,4 @@
+``pylint`` runs (at least) ~5% faster after improvements to ``astroid``
+that make better use of the inference cache.
+
+Refs pylint-dev/astroid#529
diff --git a/pylint/checkers/design_analysis.py b/pylint/checkers/design_analysis.py
index bea1ef53cc..f8c1d5c6c9 100644
--- a/pylint/checkers/design_analysis.py
+++ b/pylint/checkers/design_analysis.py
@@ -440,11 +440,20 @@ def visit_classdef(self, node: nodes.ClassDef) -> None:
                 args=(nb_parents, self.linter.config.max_parents),
             )
 
-        if len(node.instance_attrs) > self.linter.config.max_attributes:
+        # Something at inference time is modifying instance_attrs to add
+        # properties from parent classes. Given how much we cache inference
+        # results, mutating instance_attrs can become a real mess. Filter
+        # them out here until the root cause is solved.
+        # https://github.com/pylint-dev/astroid/issues/2273
+        root = node.root()
+        filtered_attrs = [
+            k for (k, v) in node.instance_attrs.items() if v[0].root() is root
+        ]
+        if len(filtered_attrs) > self.linter.config.max_attributes:
             self.add_message(
                 "too-many-instance-attributes",
                 node=node,
-                args=(len(node.instance_attrs), self.linter.config.max_attributes),
+                args=(len(filtered_attrs), self.linter.config.max_attributes),
             )
 
     @only_required_for_messages("too-few-public-methods", "too-many-public-methods")
diff --git a/pylint/checkers/typecheck.py b/pylint/checkers/typecheck.py
index f95bf4c2ed..aff1ceceac 100644
--- a/pylint/checkers/typecheck.py
+++ b/pylint/checkers/typecheck.py
@@ -12,11 +12,10 @@
 import re
 import shlex
 import sys
-import types
-from collections.abc import Callable, Iterable, Iterator, Sequence
+from collections.abc import Callable, Iterable
 from functools import cached_property, singledispatch
 from re import Pattern
-from typing import TYPE_CHECKING, Any, Literal, TypeVar, Union
+from typing import TYPE_CHECKING, Any, Literal, Union
 
 import astroid
 import astroid.exceptions
@@ -64,8 +63,6 @@
     nodes.ClassDef,
 ]
 
-_T = TypeVar("_T")
-
 STR_FORMAT = {"builtins.str.format"}
 ASYNCIO_COROUTINE = "asyncio.coroutines.coroutine"
 BUILTIN_TUPLE = "builtins.tuple"
@@ -105,24 +102,6 @@ class VERSION_COMPATIBLE_OVERLOAD:
 VERSION_COMPATIBLE_OVERLOAD_SENTINEL = VERSION_COMPATIBLE_OVERLOAD()
 
 
-def _unflatten(iterable: Iterable[_T]) -> Iterator[_T]:
-    for index, elem in enumerate(iterable):
-        if isinstance(elem, Sequence) and not isinstance(elem, str):
-            yield from _unflatten(elem)
-        elif elem and not index:
-            # We're interested only in the first element.
-            yield elem  # type: ignore[misc]
-
-
-def _flatten_container(iterable: Iterable[_T]) -> Iterator[_T]:
-    # Flatten nested containers into a single iterable
-    for item in iterable:
-        if isinstance(item, (list, tuple, types.GeneratorType)):
-            yield from _flatten_container(item)
-        else:
-            yield item
-
-
 def _is_owner_ignored(
     owner: SuccessfulInferenceResult,
     attrname: str | None,
@@ -1899,16 +1878,13 @@ def visit_with(self, node: nodes.With) -> None:
 
                 # Retrieve node from all previously visited nodes in the
                 # inference history
-                context_path_names: Iterator[Any] = filter(
-                    None, _unflatten(context.path)
-                )
-                inferred_paths = _flatten_container(
-                    safe_infer(path) for path in context_path_names
-                )
-                for inferred_path in inferred_paths:
+                for inferred_path, _ in context.path:
                     if not inferred_path:
                         continue
-                    scope = inferred_path.scope()
+                    if isinstance(inferred_path, nodes.Call):
+                        scope = safe_infer(inferred_path.func)
+                    else:
+                        scope = inferred_path.scope()
                     if not isinstance(scope, nodes.FunctionDef):
                         continue
                     if decorated_with(
diff --git a/pyproject.toml b/pyproject.toml
index f81a7933ed..dae9cfed5b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -41,7 +41,7 @@ dependencies    = [
     # Also upgrade requirements_test_min.txt.
     # Pinned to dev of second minor update to allow editable installs and fix primer issues,
     # see https://github.com/pylint-dev/astroid/issues/1341
-    "astroid>=3.0.0a8,<=3.1.0-dev0",
+    "astroid @ git+https://github.com/pylint-dev/astroid.git@cf8763a2b8e897ec7c8389906f3cb13714300cd2",
     "isort>=4.2.5,<6",
     "mccabe>=0.6,<0.8",
     "tomli>=1.1.0;python_version<'3.11'",
diff --git a/requirements_test_min.txt b/requirements_test_min.txt
index 7df78810f2..b2b928f98d 100644
--- a/requirements_test_min.txt
+++ b/requirements_test_min.txt
@@ -1,6 +1,6 @@
 -e .[testutils,spelling]
 # astroid dependency is also defined in pyproject.toml
-astroid==3.0.0a8  # Pinned to a specific version for tests
+astroid @ git+https://github.com/pylint-dev/astroid.git@cf8763a2b8e897ec7c8389906f3cb13714300cd2
 typing-extensions~=4.7
 py~=1.11.0
 pytest~=7.4