AdamHillier: The behaviour here mimics a [similar method](https://docs.python.org/3/library/dataclasses.html#post-init-processing) defined for Python dataclasses.
leonoverweel: I'll take a look at this today.
diff --git a/zookeeper/core/component.py b/zookeeper/core/component.py
index 6180ab1..ebf57a5 100644
--- a/zookeeper/core/component.py
+++ b/zookeeper/core/component.py
@@ -385,6 +385,20 @@ def component(cls: Type):
         raise TypeError("Component classes must not define a custom `__init__` method.")
     cls.__init__ = __component_init__
 
+    if hasattr(cls, "__post_configure__"):
+        if not callable(cls.__post_configure__):
+            raise TypeError(
+                "The `__post_configure__` attribute of a @component class must be a "
+                "method."
+            )
+        call_args = inspect.signature(cls.__post_configure__).parameters
+        if len(call_args) > 1 or len(call_args) == 1 and "self" not in call_args:
+            raise TypeError(
+                "The `__post_configure__` method of a @component class must take no "
+                f"arguments except `self`, but `{cls.__name__}.__post_configure__` "
+                f"accepts arguments {tuple(name for name in call_args)}."
+            )
+
     # Populate `__component_fields__` with all fields defined on this class and
     # all superclasses. We have to go through the MRO chain and collect them in
     # reverse order so that they are correctly overriden.
@@ -611,3 +625,6 @@ def configure(
             )
 
     instance.__component_configured__ = True
+
+    if hasattr(instance.__class__, "__post_configure__"):
+        instance.__post_configure__()

Include some sort of post-configure hook
We got rid of `validate_configuration`; maybe it can be replaced with `__component_configured__` or something similar.
diff --git a/zookeeper/core/component_test.py b/zookeeper/core/component_test.py
index 7c1f232..f98f2c3 100644
--- a/zookeeper/core/component_test.py
+++ b/zookeeper/core/component_test.py
@@ -409,3 +409,39 @@ def test_component_field_factory_type_check(capsys):
         captured.err
         == "WARNING: Unable to check that typing.Tuple[int, int, int] is a sub-type of typing.Tuple[float, float, float].\n"
     )
+
+
+def test_component_post_configure():
+    with pytest.raises(
+        TypeError,
+        match="The `__post_configure__` attribute of a @component class must be a method.",
+    ):
+
+        @component
+        class A:
+            __post_configure__ = 3.14
+
+    with pytest.raises(
+        TypeError,
+        match="The `__post_configure__` method of a @component class must take no arguments except `self`",
+    ):
+
+        @component
+        class B:
+            def __post_configure__(self, x):
+                pass
+
+    # This definition should succeed.
+    @component
+    class C:
+        a: int = Field(0)
+        b: float = Field(3.14)
+
+        def __post_configure__(self):
+            self.c = self.a + self.b
+
+    c = C()
+
+    configure(c, {"a": 1, "b": -3.14})
+
+    assert c.c == 1 - 3.14

pip install -e .
parse_log_pytest
requirements.txt
pytest pytest-cov pytest-flake8 pytest-catchlog
apt-get update apt-get install -y gcc
3.6
pytest --no-header -rA --tb=line --color=no -p no:cacheprovider -W ignore::DeprecationWarning
absl-py==0.12.0
attrs==22.2.0
certifi==2021.5.30
charset-normalizer==2.0.12
click==8.0.4
coverage==6.2
dataclasses==0.8
dill==0.3.4
flake8==5.0.4
googleapis-common-protos==1.56.3
idna==3.10
importlib-metadata==4.2.0
importlib-resources==5.4.0
iniconfig==1.1.1
mccabe==0.7.0
numpy==1.19.5
packaging==21.3
pluggy==1.0.0
promise==2.3
prompt-toolkit==3.0.36
protobuf==3.19.6
py==1.11.0
pycodestyle==2.9.1
pyflakes==2.5.0
pyparsing==3.1.4
pytest==7.0.1
pytest-catchlog==1.2.2
pytest-cov==4.0.0
pytest-flake8==1.1.1
requests==2.27.1
six==1.17.0
tensorflow-datasets==4.5.2
tensorflow-metadata==1.2.0
termcolor==1.1.0
tomli==1.2.3
tqdm==4.64.1
typeguard==2.13.3
typing_extensions==4.1.1
urllib3==1.26.20
wcwidth==0.2.13
zipp==3.6.0
-e git+https://github.com/larq/zookeeper.git@c48fa65d42f040c0134318e4393facb5a0941a33#egg=zookeeper

name: zookeeper
channels:
  - defaults
  - https://repo.anaconda.com/pkgs/main
  - https://repo.anaconda.com/pkgs/r
  - conda-forge
dependencies:
  - _libgcc_mutex=0.1=main
  - _openmp_mutex=5.1=1_gnu
  - ca-certificates=2025.2.25=h06a4308_0
  - certifi=2021.5.30=py36h06a4308_0
  - ld_impl_linux-64=2.40=h12ee557_0
  - libffi=3.3=he6710b0_2
  - libgcc-ng=11.2.0=h1234567_1
  - libgomp=11.2.0=h1234567_1
  - libstdcxx-ng=11.2.0=h1234567_1
  - ncurses=6.4=h6a678d5_0
  - openssl=1.1.1w=h7f8727e_0
  - pip=21.2.2=py36h06a4308_0
  - python=3.6.13=h12debd9_1
  - readline=8.2=h5eee18b_0
  - setuptools=58.0.4=py36h06a4308_0
  - sqlite=3.45.3=h5eee18b_0
  - tk=8.6.14=h39e8969_0
  - wheel=0.37.1=pyhd3eb1b0_0
  - xz=5.6.4=h5eee18b_1
  - zlib=1.2.13=h5eee18b_1
  - pip:
      - absl-py==0.12.0
      - attrs==22.2.0
      - charset-normalizer==2.0.12
      - click==8.0.4
      - coverage==6.2
      - dataclasses==0.8
      - dill==0.3.4
      - flake8==5.0.4
      - googleapis-common-protos==1.56.3
      - idna==3.10
      - importlib-metadata==4.2.0
      - importlib-resources==5.4.0
      - iniconfig==1.1.1
      - mccabe==0.7.0
      - numpy==1.19.5
      - packaging==21.3
      - pluggy==1.0.0
      - promise==2.3
      - prompt-toolkit==3.0.36
      - protobuf==3.19.6
      - py==1.11.0
      - pycodestyle==2.9.1
      - pyflakes==2.5.0
      - pyparsing==3.1.4
      - pytest==7.0.1
      - pytest-catchlog==1.2.2
      - pytest-cov==4.0.0
      - pytest-flake8==1.1.1
      - requests==2.27.1
      - six==1.17.0
      - tensorflow-datasets==4.5.2
      - tensorflow-metadata==1.2.0
      - termcolor==1.1.0
      - tomli==1.2.3
      - tqdm==4.64.1
      - typeguard==2.13.3
      - typing-extensions==4.1.1
      - urllib3==1.26.20
      - wcwidth==0.2.13
      - zipp==3.6.0
prefix: /opt/conda/envs/zookeeper

zookeeper/core/component_test.py::test_component_post_configure
zookeeper/core/component_test.py::test_non_class_decorate_error zookeeper/core/component_test.py::test_abstract_class_decorate_error zookeeper/core/component_test.py::test_init_decorate_error zookeeper/core/component_test.py::test_no_init zookeeper/core/component_test.py::test_configure_override_field_values zookeeper/core/component_test.py::test_configure_scoped_override_field_values zookeeper/core/component_test.py::test_configure_automatically_instantiate_subcomponent zookeeper/core/component_test.py::test_configure_non_interactive_missing_field_value zookeeper/core/component_test.py::test_configure_interactive_prompt_missing_field_value zookeeper/core/component_test.py::test_configure_interactive_prompt_for_subcomponent_choice zookeeper/core/component_test.py::test_str_and_repr zookeeper/core/component_test.py::test_type_check zookeeper/core/component_test.py::test_error_if_field_overwritten_in_subclass zookeeper/core/component_test.py::test_component_field_optional_type_check zookeeper/core/component_test.py::test_component_field_factory_type_check
zookeeper/core/component.py
zookeeper/core/component.py