diff --git a/.gitignore b/.gitignore
index 35db05af..49738283 100644
--- a/.gitignore
+++ b/.gitignore
@@ -36,6 +36,9 @@ _version.py
 node_modules/
 .code-workspace
 
+# memray report
+*.bin
+
 # test datasets (e.g. Xenium ones)
 # symlinks
 data
diff --git a/asv.conf.json b/asv.conf.json
index 55f61b90..c3005b58 100644
--- a/asv.conf.json
+++ b/asv.conf.json
@@ -3,10 +3,10 @@
     "project": "spatialdata-io",
     "project_url": "https://github.com/scverse/spatialdata-io",
     "repo": ".",
-    "branches": ["image-reader-chunkwise"],
+    "branches": ["faster-imports", "main"],
     "dvcs": "git",
     "environment_type": "virtualenv",
-    "pythons": ["3.12"],
+    "pythons": ["3.13"],
     "build_command": [],
     "install_command": ["python -m pip install {build_dir}[test]"],
     "uninstall_command": ["python -m pip uninstall -y {project}"],
@@ -17,7 +17,7 @@
     "hash_length": 8,
     "build_cache_size": 2,
     "install_timeout": 600,
-    "repeat": 3,
+    "repeat": 5,
     "processes": 1,
     "attribute_selection": ["time_*", "peakmem_*"]
 }
diff --git a/benchmarks/benchmark_image.py b/benchmarks/benchmark_image.py
index 3096fee7..1b660edf 100644
--- a/benchmarks/benchmark_image.py
+++ b/benchmarks/benchmark_image.py
@@ -16,7 +16,7 @@
 from spatialdata._logging import logger
 from xarray import DataArray
 
-from spatialdata_io import image  # type: ignore[attr-defined]
+from spatialdata_io import image
 
 # =============================================================================
 # CONFIGURATION - Edit these values to match your setup
diff --git a/benchmarks/benchmark_imports.py b/benchmarks/benchmark_imports.py
new file mode 100644
index 00000000..9a1ca1b6
--- /dev/null
+++ b/benchmarks/benchmark_imports.py
@@ -0,0 +1,103 @@
+"""ASV benchmarks for spatialdata-io import times.
+
+Measures how long it takes to import the package and individual readers
+in a fresh subprocess, isolating import overhead from runtime work.
+
+Running (with the current environment, no virtualenv rebuild):
+    # Quick sanity check (single iteration):
+    asv run --python=same --quick --show-stderr -v -b ImportBenchmark
+
+    # Full benchmark on current commit:
+    asv run --python=same --show-stderr -v -b ImportBenchmark
+
+    # Compare two branches (using --python=same, one-liner):
+    git stash && git checkout main && pip install -e . -q \
+        && asv run --python=same -v -b ImportBenchmark \
+        && git checkout faster-imports && git stash pop && pip install -e . -q \
+        && asv run --python=same -v -b ImportBenchmark
+    # Then view the comparison:
+    asv compare $(git rev-parse main) $(git rev-parse faster-imports)
+
+    # Compare two branches (let ASV build virtualenvs, slower first run):
+    asv continuous --show-stderr -v -b ImportBenchmark main faster-imports
+
+    # Generate an HTML report:
+    asv publish && asv preview
+"""
+
+import subprocess
+import sys
+
+
+def _import_time(statement: str) -> float:
+    """Time an import in a fresh subprocess. Returns seconds."""
+    code = f"import time; t0=time.perf_counter(); {statement}; print(time.perf_counter()-t0)"
+    result = subprocess.run(
+        [sys.executable, "-c", code],
+        capture_output=True,
+        text=True,
+    )
+    if result.returncode != 0:
+        raise RuntimeError(result.stderr)
+    return float(result.stdout.strip())
+
+
+class ImportBenchmark:
+    """Import-time benchmarks for spatialdata-io.
+
+    Each ``time_*`` method is a separate ASV benchmark.
+    They run in isolated subprocesses so that one import
+    does not warm the cache for the next.
+    """
+
+    # ASV settings tuned for subprocess-based import timing:
+    timeout = 120  # seconds before ASV kills a benchmark; generous since each
+    # call spawns a subprocess (~2s each × 10 repeats = ~20s worst case)
+    repeat = 5  # number of timing samples ASV collects; high because import
+    # times have variance from OS caching / disk I/O / background load;
+    # ASV reports the median and IQR from these samples
+    number = 1  # calls per sample; must be 1 because each call spawns a fresh
+    # subprocess — running >1 would just re-import in a warm process
+    warmup_time = 0  # seconds of warm-up iterations before timing; disabled because
+    # each call is already a cold subprocess — warming up the parent
+    # process is meaningless
+    processes = 1  # number of ASV worker processes; 1 avoids parallel subprocesses
+    # competing for CPU / disk and inflating timings
+
+    # -- top-level package -------------------------------------------------
+
+    def time_import_spatialdata_io(self) -> float:
+        """Wall time: ``import spatialdata_io`` (lazy, no readers loaded)."""
+        return _import_time("import spatialdata_io")
+
+    # -- single reader via the public API ----------------------------------
+
+    def time_from_spatialdata_io_import_xenium(self) -> float:
+        """Wall time: ``from spatialdata_io import xenium``."""
+        return _import_time("from spatialdata_io import xenium")
+
+    def time_from_spatialdata_io_import_visium(self) -> float:
+        """Wall time: ``from spatialdata_io import visium``."""
+        return _import_time("from spatialdata_io import visium")
+
+    def time_from_spatialdata_io_import_visium_hd(self) -> float:
+        """Wall time: ``from spatialdata_io import visium_hd``."""
+        return _import_time("from spatialdata_io import visium_hd")
+
+    def time_from_spatialdata_io_import_merscope(self) -> float:
+        """Wall time: ``from spatialdata_io import merscope``."""
+        return _import_time("from spatialdata_io import merscope")
+
+    def time_from_spatialdata_io_import_cosmx(self) -> float:
+        """Wall time: ``from spatialdata_io import cosmx``."""
+        return _import_time("from spatialdata_io import cosmx")
+
+    # -- key dependencies (reference) --------------------------------------
+
+    def time_import_spatialdata(self) -> float:
+        """Wall time: ``import spatialdata`` (reference)."""
+        return _import_time("import spatialdata")
+
+    def time_import_anndata(self) -> float:
+        """Wall time: ``import anndata`` (reference)."""
+        return _import_time("import anndata")
diff --git a/benchmarks/benchmark_xenium.py b/benchmarks/benchmark_xenium.py
index b1f09afe..58ac614f 100644
--- a/benchmarks/benchmark_xenium.py
+++ b/benchmarks/benchmark_xenium.py
@@ -39,7 +39,7 @@
 
 from spatialdata import SpatialData
 
-from spatialdata_io import xenium  # type: ignore[attr-defined]
+from spatialdata_io import xenium
 
 # =============================================================================
 # CONFIGURATION - Edit these paths to match your setup
diff --git a/pyproject.toml b/pyproject.toml
index 6c1e6095..d97dc276 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -185,6 +185,8 @@ lint.ignore = [
     # Unused imports
     "F401",
 ]
+[tool.ruff.lint.per-file-ignores]
+"src/spatialdata_io/__init__.py" = ["I001"]
 
 [tool.jupytext]
 formats = "ipynb,md"
diff --git a/src/spatialdata_io/__init__.py b/src/spatialdata_io/__init__.py
index 0648c09e..8badb295 100644
--- a/src/spatialdata_io/__init__.py
+++ b/src/spatialdata_io/__init__.py
@@ -1,26 +1,36 @@
+from importlib import import_module
 from importlib.metadata import version
+from typing import Any, TYPE_CHECKING
 
-from spatialdata_io.converters.generic_to_zarr import generic_to_zarr
-from spatialdata_io.readers.codex import codex
-from spatialdata_io.readers.cosmx import cosmx
-from spatialdata_io.readers.curio import curio
-from spatialdata_io.readers.dbit import dbit
-from spatialdata_io.readers.generic import generic, geojson, image
-from spatialdata_io.readers.macsima import macsima
-from spatialdata_io.readers.mcmicro import mcmicro
-from spatialdata_io.readers.merscope import merscope
-from spatialdata_io.readers.seqfish import seqfish
-from spatialdata_io.readers.steinbock import steinbock
-from spatialdata_io.readers.stereoseq import stereoseq
-from spatialdata_io.readers.visium import visium
-from spatialdata_io.readers.visium_hd import visium_hd
-from spatialdata_io.readers.xenium import (
-    xenium,
-    xenium_aligned_image,
-    xenium_explorer_selection,
-)
-
-_readers_technologies = [
+__version__ = version("spatialdata-io")
+
+_LAZY_IMPORTS: dict[str, str] = {
+    # readers
+    "codex": "spatialdata_io.readers.codex",
+    "cosmx": "spatialdata_io.readers.cosmx",
+    "curio": "spatialdata_io.readers.curio",
+    "dbit": "spatialdata_io.readers.dbit",
+    "macsima": "spatialdata_io.readers.macsima",
+    "mcmicro": "spatialdata_io.readers.mcmicro",
+    "merscope": "spatialdata_io.readers.merscope",
+    "seqfish": "spatialdata_io.readers.seqfish",
+    "steinbock": "spatialdata_io.readers.steinbock",
+    "stereoseq": "spatialdata_io.readers.stereoseq",
+    "visium": "spatialdata_io.readers.visium",
+    "visium_hd": "spatialdata_io.readers.visium_hd",
+    "xenium": "spatialdata_io.readers.xenium",
+    "xenium_aligned_image": "spatialdata_io.readers.xenium",
+    "xenium_explorer_selection": "spatialdata_io.readers.xenium",
+    # readers file types
+    "generic": "spatialdata_io.readers.generic",
+    "geojson": "spatialdata_io.readers.generic",
+    "image": "spatialdata_io.readers.generic",
+    # converters
+    "generic_to_zarr": "spatialdata_io.converters.generic_to_zarr",
+}
+
+__all__ = [
+    # readers
     "codex",
     "cosmx",
     "curio",
@@ -34,28 +44,57 @@
     "visium",
     "visium_hd",
     "xenium",
-]
-
-_readers_file_types = [
+    "xenium_aligned_image",
+    "xenium_explorer_selection",
+    # readers file types
     "generic",
-    "image",
     "geojson",
-]
-
-_converters = [
+    "image",
+    # converters
     "generic_to_zarr",
 ]
 
 
-__all__ = (
-    [
-        "xenium_aligned_image",
-        "xenium_explorer_selection",
-    ]
-    + _readers_technologies
-    + _readers_file_types
-    + _converters
-)
+def __getattr__(name: str) -> Any:
+    if name in _LAZY_IMPORTS:
+        module_path = _LAZY_IMPORTS[name]
+        mod = import_module(module_path)
+        val = getattr(mod, name)
+        globals()[name] = val
+        return val
+    else:
+        try:
+            return globals()[name]
+        except KeyError as e:
+            raise AttributeError(f"Module 'spatialdata_io' has no attribute '{name}'") from e
 
 
-__version__ = version("spatialdata-io")
+def __dir__() -> list[str]:
+    return __all__ + ["__version__"]
+
+
+if TYPE_CHECKING:
+    # readers
+    from spatialdata_io.readers.codex import codex
+    from spatialdata_io.readers.cosmx import cosmx
+    from spatialdata_io.readers.curio import curio
+    from spatialdata_io.readers.dbit import dbit
+    from spatialdata_io.readers.macsima import macsima
+    from spatialdata_io.readers.mcmicro import mcmicro
+    from spatialdata_io.readers.merscope import merscope
+    from spatialdata_io.readers.seqfish import seqfish
+    from spatialdata_io.readers.steinbock import steinbock
+    from spatialdata_io.readers.stereoseq import stereoseq
+    from spatialdata_io.readers.visium import visium
+    from spatialdata_io.readers.visium_hd import visium_hd
+    from spatialdata_io.readers.xenium import (
+        xenium,
+        xenium_aligned_image,
+        xenium_explorer_selection,
+    )
+
+    # readers file types
+    from spatialdata_io.readers.generic import generic, geojson, image
+
+    # converters
+    from spatialdata_io.converters.generic_to_zarr import generic_to_zarr
diff --git a/src/spatialdata_io/__main__.py b/src/spatialdata_io/__main__.py
index 35fd24de..970bf180 100644
--- a/src/spatialdata_io/__main__.py
+++ b/src/spatialdata_io/__main__.py
@@ -1,31 +1,12 @@
-import importlib
 from collections.abc import Callable
 from pathlib import Path
 from typing import Any, Literal
 
 import click
 
-# dynamically import all readers and converters (also the experimental ones)
-from spatialdata_io import _converters, _readers_file_types, _readers_technologies
 from spatialdata_io._constants._constants import VisiumKeys
-from spatialdata_io.converters.generic_to_zarr import generic_to_zarr
-from spatialdata_io.experimental import _converters as _experimental_converters
-from spatialdata_io.experimental import (
-    _readers_file_types as _experimental_readers_file_types,
-)
-from spatialdata_io.experimental import (
-    _readers_technologies as _experimental_readers_technologies,
-)
 from spatialdata_io.readers.generic import VALID_IMAGE_TYPES, VALID_SHAPE_TYPES
 
-for func in _readers_technologies + _readers_file_types + _converters:
-    module = importlib.import_module("spatialdata_io")
-    globals()[func] = getattr(module, func)
-
-for func in _experimental_readers_technologies + _experimental_readers_file_types + _experimental_converters:
-    module = importlib.import_module("spatialdata_io.experimental")
-    globals()[func] = getattr(module, func)
-
 
 @click.group()
 def cli() -> None:
@@ -66,7 +47,9 @@ def _input_output_click_options(func: Callable[..., None]) -> Callable[..., None
 )
 def codex_wrapper(input: str, output: str, fcs: bool = True) -> None:
     """Codex conversion to SpatialData."""
-    sdata = codex(input, fcs=fcs)  # type: ignore[name-defined] # noqa: F821
+    from spatialdata_io.readers.codex import codex
+
+    sdata = codex(input, fcs=fcs)
     sdata.write(output)
 
 
@@ -76,7 +59,9 @@ def codex_wrapper(input: str, output: str, fcs: bool = True) -> None:
 @click.option("--transcripts", type=bool, default=True, help="Whether to load transcript information. [default: True]")
 def cosmx_wrapper(input: str, output: str, dataset_id: str | None = None, transcripts: bool = True) -> None:
     """Cosmic conversion to SpatialData."""
-    sdata = cosmx(input, dataset_id=dataset_id, transcripts=transcripts)  # type: ignore[name-defined] # noqa: F821
+    from spatialdata_io.readers.cosmx import cosmx
+
+    sdata = cosmx(input, dataset_id=dataset_id, transcripts=transcripts)
     sdata.write(output)
 
 
@@ -84,7 +69,9 @@ def cosmx_wrapper(input: str, output: str, dataset_id: str | None = None, transc
 @_input_output_click_options
 def curio_wrapper(input: str, output: str) -> None:
     """Curio conversion to SpatialData."""
-    sdata = curio(input)  # type: ignore[name-defined] # noqa: F821
+    from spatialdata_io.readers.curio import curio
+
+    sdata = curio(input)
     sdata.write(output)
 
 
@@ -117,7 +104,9 @@ def dbit_wrapper(
     border_scale: float = 1,
 ) -> None:
     """Conversion of DBit-seq to SpatialData."""
-    sdata = dbit(  # type: ignore[name-defined] # noqa: F821
+    from spatialdata_io.readers.dbit import dbit
+
+    sdata = dbit(
         input,
         anndata_path=anndata_path,
         barcode_position=barcode_position,
@@ -174,7 +163,9 @@ def iss_wrapper(
     multiscale_labels: bool = True,
 ) -> None:
     """ISS conversion to SpatialData."""
-    sdata = iss(  # type: ignore[name-defined] # noqa: F821
+    from spatialdata_io.readers.iss import iss
+
+    sdata = iss(
         input,
         raw_relative_path,
         labels_relative_path,
@@ -194,7 +185,9 @@ def iss_wrapper(
 @click.option("--output", "-o", type=click.Path(), help="Path to the output.zarr file.", required=True)
 def mcmicro_wrapper(input: str, output: str) -> None:
     """Conversion of MCMicro to SpatialData."""
-    sdata = mcmicro(input)  # type: ignore[name-defined] # noqa: F821
+    from spatialdata_io.readers.mcmicro import mcmicro
+
+    sdata = mcmicro(input)
     sdata.write(output)
 
 
@@ -233,7 +226,9 @@ def merscope_wrapper(
     mosaic_images: bool = True,
 ) -> None:
     """Merscope conversion to SpatialData."""
-    sdata = merscope(  # type: ignore[name-defined] # noqa: F821
+    from spatialdata_io.readers.merscope import merscope
+
+    sdata = merscope(
         input,
         vpt_outputs=vpt_outputs,
         z_layers=z_layers,
@@ -273,8 +268,10 @@ def seqfish_wrapper(
     rois: list[int] | None = None,
 ) -> None:
     """Seqfish conversion to SpatialData."""
+    from spatialdata_io.readers.seqfish import seqfish
+
     rois = list(rois) if rois else None
-    sdata = seqfish(  # type: ignore[name-defined] # noqa: F821
+    sdata = seqfish(
         input,
         load_images=load_images,
         load_labels=load_labels,
@@ -296,7 +293,9 @@ def seqfish_wrapper(
 )
 def steinbock_wrapper(input: str, output: str, labels_kind: Literal["deepcell", "ilastik"] = "deepcell") -> None:
     """Steinbock conversion to SpatialData."""
-    sdata = steinbock(input, labels_kind=labels_kind)  # type: ignore[name-defined] # noqa: F821
+    from spatialdata_io.readers.steinbock import steinbock
+
+    sdata = steinbock(input, labels_kind=labels_kind)
     sdata.write(output)
 
 
@@ -320,7 +319,9 @@ def stereoseq_wrapper(
     optional_tif: bool = False,
 ) -> None:
     """Stereoseq conversion to SpatialData."""
-    sdata = stereoseq(input, dataset_id=dataset_id, read_square_bin=read_square_bin, optional_tif=optional_tif)  # type: ignore[name-defined] # noqa: F821
+    from spatialdata_io.readers.stereoseq import stereoseq
+
+    sdata = stereoseq(input, dataset_id=dataset_id, read_square_bin=read_square_bin, optional_tif=optional_tif)
     sdata.write(output)
 
 
@@ -361,7 +362,9 @@ def visium_wrapper(
     scalefactors_file: str | Path | None = None,
 ) -> None:
     """Visium conversion to SpatialData."""
-    sdata = visium(  # type: ignore[name-defined] # noqa: F821
+    from spatialdata_io.readers.visium import visium
+
+    sdata = visium(
         input,
         dataset_id=dataset_id,
         counts_file=counts_file,
@@ -437,7 +440,9 @@ def visium_hd_wrapper(
     annotate_table_by_labels: bool = False,
 ) -> None:
     """Visium HD conversion to SpatialData."""
-    sdata = visium_hd(  # type: ignore[name-defined] # noqa: F821
+    from spatialdata_io.readers.visium_hd import visium_hd
+
+    sdata = visium_hd(
         path=input,
         dataset_id=dataset_id,
         filtered_counts_file=filtered_counts_file,
@@ -496,7 +501,9 @@ def xenium_wrapper(
     cells_table: bool = True,
 ) -> None:
     """Xenium conversion to SpatialData."""
-    sdata = xenium(  # type: ignore[name-defined] # noqa: F821
+    from spatialdata_io.readers.xenium import xenium
+
+    sdata = xenium(
         input,
         cells_boundaries=cells_boundaries,
         nucleus_boundaries=nucleus_boundaries,
@@ -595,7 +602,9 @@ def macsima_wrapper(
     include_cycle_in_channel_name: bool = False,
 ) -> None:
     """Read MACSima formatted dataset and convert to SpatialData."""
-    sdata = macsima(  # type: ignore[name-defined] # noqa: F821
+    from spatialdata_io.readers.macsima import macsima
+
+    sdata = macsima(
         path=input,
         filter_folder_names=filter_folder_names,
         subset=subset,
@@ -649,6 +658,8 @@ def read_generic_wrapper(
     coordinate_system: str | None = None,
 ) -> None:
     """Read generic data to SpatialData."""
+    from spatialdata_io.converters.generic_to_zarr import generic_to_zarr
+
     if data_axes is not None and "".join(sorted(data_axes)) not in ["cxy", "cxyz"]:
         raise ValueError("data_axes must be a permutation of 'cyx' or 'czyx'.")
     generic_to_zarr(input=input, output=output, name=name, data_axes=data_axes, coordinate_system=coordinate_system)
diff --git a/src/spatialdata_io/readers/_utils/_image.py b/src/spatialdata_io/readers/_utils/_image.py
index c5c8d7e3..deba6bf6 100644
--- a/src/spatialdata_io/readers/_utils/_image.py
+++ b/src/spatialdata_io/readers/_utils/_image.py
@@ -1,12 +1,18 @@
-from collections.abc import Callable, Mapping, Sequence
-from typing import Any
+from __future__ import annotations
+
+from collections.abc import Mapping, Sequence
+from typing import TYPE_CHECKING, Any
 
 import dask.array as da
 import numpy as np
 from dask import delayed
-from numpy.typing import NDArray
 from spatialdata.models.models import Chunks_t
 
+if TYPE_CHECKING:
+    from collections.abc import Callable
+
+    from numpy.typing import NDArray
+
 __all__ = ["Chunks_t", "_compute_chunks", "_read_chunks"]
 
 _Y_IDX = 0
diff --git a/src/spatialdata_io/readers/_utils/_utils.py b/src/spatialdata_io/readers/_utils/_utils.py
index 1dbd496f..75eb8c5f 100644
--- a/src/spatialdata_io/readers/_utils/_utils.py
+++ b/src/spatialdata_io/readers/_utils/_utils.py
@@ -7,8 +7,6 @@
 from anndata import AnnData
 from anndata.io import read_text
 from h5py import File
-from ome_types import from_tiff
-from ome_types.model import Pixels, UnitsLength
 from spatialdata._logging import logger
 
 from spatialdata_io.readers._utils._read_10x_h5 import _read_10x_h5
@@ -17,6 +15,7 @@
     from collections.abc import Mapping
 
     from anndata import AnnData
+    from ome_types.model import Pixels
     from spatialdata import SpatialData
 
 PathLike = os.PathLike | str  # type:ignore[type-arg]
@@ -101,6 +100,8 @@ def calc_scale_factors(lower_scale_limit: float, min_size: int = 1000, default_s
 
 def parse_channels(path: Path) -> list[str]:
     """Parse channel names from an OME-TIFF file."""
+    from ome_types import from_tiff
+
     images = from_tiff(path).images
     if len(images) > 1:
         logger.warning("Found multiple images in OME-TIFF file. Only the first one will be used.")
@@ -121,6 +122,9 @@ def _set_reader_metadata(sdata: SpatialData, reader: str) -> SpatialData:
 
 def parse_physical_size(path: Path | None = None, ome_pixels: Pixels | None = None) -> float:
     """Parse physical size from OME-TIFF to micrometer."""
+    from ome_types import from_tiff
+    from ome_types.model import UnitsLength
+
     pixels = ome_pixels or from_tiff(path).images[0].pixels
     logger.debug(pixels)
     if pixels.physical_size_x_unit != pixels.physical_size_y_unit:
diff --git a/src/spatialdata_io/readers/generic.py b/src/spatialdata_io/readers/generic.py
index 95bcf66c..c0d9bc3e 100644
--- a/src/spatialdata_io/readers/generic.py
+++ b/src/spatialdata_io/readers/generic.py
@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 from pathlib import Path
-from typing import TYPE_CHECKING, Protocol, TypeVar
+from typing import TYPE_CHECKING
 
 import dask.array as da
 import numpy as np
@@ -35,12 +35,6 @@
 
 __all__ = ["generic", "geojson", "image", "VALID_IMAGE_TYPES", "VALID_SHAPE_TYPES"]
 
-T = TypeVar("T", bound=np.generic)  # Restrict to NumPy scalar types
-
-
-class DaskArray(Protocol[T]):
-    dtype: np.dtype[T]
-
 
 @docstring_parameter(
     valid_image_types=", ".join(VALID_IMAGE_TYPES),
@@ -96,7 +90,7 @@ def _tiff_to_chunks(
     input: Path,
     axes_dim_mapping: dict[str, int],
     chunks_cyx: dict[str, int],
-) -> list[list[DaskArray[np.number]]]:
+) -> list[list[da.Array]]:
     """Chunkwise reader for tiff files.
 
     Creates spatial tiles from a TIFF file. Each tile contains all channels.
@@ -115,7 +109,7 @@ def _tiff_to_chunks(
 
     Returns
     -------
-    list[list[DaskArray]]
+    list[list[dask.array.Array]]
         2D list of dask arrays representing spatial tiles, each with shape (n_channels, height, width).
     """
     # Lazy file reader
diff --git a/src/spatialdata_io/readers/xenium.py b/src/spatialdata_io/readers/xenium.py
index 01121c3d..ec7258a9 100644
--- a/src/spatialdata_io/readers/xenium.py
+++ b/src/spatialdata_io/readers/xenium.py
@@ -11,7 +11,6 @@
 
 import dask.array as da
 import numpy as np
-import ome_types
 import packaging.version
 import pandas as pd
 import pyarrow.compute as pc
@@ -353,6 +352,9 @@ def xenium(
                         3: XeniumKeys.MORPHOLOGY_FOCUS_CHANNEL_3.value,
                     }
             else:
+                # slow import
+                from ome_types import from_xml
+
                 # v4
                 if XeniumKeys.MORPHOLOGY_FOCUS_V4_DAPI_FILENAME.value not in files:
                     raise ValueError(
@@ -360,7 +362,7 @@ def xenium(
                         f"chNNNN_<name>.ome.tif starting with {XeniumKeys.MORPHOLOGY_FOCUS_V4_DAPI_FILENAME.value}"
                     )
                 first_tiff_path = morphology_focus_dir / XeniumKeys.MORPHOLOGY_FOCUS_V4_DAPI_FILENAME.value
-                ome = ome_types.from_xml(tifffile.tiffcomment(first_tiff_path), validate=False)
+                ome = from_xml(tifffile.tiffcomment(first_tiff_path), validate=False)
 
                 # Get channel names from the OME XML
                 ome_channels = ome.images[0].pixels.channels
diff --git a/tests/test_basic.py b/tests/test_basic.py
deleted file mode 100644
index 71ac4d3a..00000000
--- a/tests/test_basic.py
+++ /dev/null
@@ -1,5 +0,0 @@
-import spatialdata_io
-
-
-def test_package_has_version() -> None:
-    assert spatialdata_io.__version__
diff --git a/tests/test_init.py b/tests/test_init.py
new file mode 100644
index 00000000..8a98211c
--- /dev/null
+++ b/tests/test_init.py
@@ -0,0 +1,23 @@
+import spatialdata_io
+
+
+def test_package_has_version() -> None:
+    assert spatialdata_io.__version__
+
+
+def test_all_matches_lazy_imports() -> None:
+    """Ensure __all__ and _LAZY_IMPORTS stay in sync."""
+    assert set(spatialdata_io.__all__) == set(spatialdata_io._LAZY_IMPORTS.keys())
+
+
+def test_all_are_importable() -> None:
+    """Every name in __all__ should be accessible on the module."""
+    for name in spatialdata_io.__all__:
+        assert hasattr(spatialdata_io, name), f"{name!r} listed in __all__ but not resolvable"
+
+
+def test_all_are_in_dir() -> None:
+    """dir(spatialdata_io) should expose everything in __all__."""
+    module_dir = dir(spatialdata_io)
+    for name in spatialdata_io.__all__:
+        assert name in module_dir, f"{name!r} missing from dir()"