diff --git a/src/audio_summary/__init__.py b/src/audio_summary/__init__.py
new file mode 100644
index 0000000..84f02e9
--- /dev/null
+++ b/src/audio_summary/__init__.py
@@ -0,0 +1 @@
+"""Transcribe and summarize audio/video files on Apple Silicon via MLX."""
diff --git a/src/audio_summary/cli.py b/src/audio_summary/cli.py
index f46d797..b972002 100644
--- a/src/audio_summary/cli.py
+++ b/src/audio_summary/cli.py
@@ -2,29 +2,23 @@
 
 Download (optional), transcribe, and summarize audio/video files fully on
 Apple Silicon via MLX. Models are selected automatically from the detected
-unified memory (see ``config`` and ``device``).
+unified memory (see ``models.config`` and ``models.device``).
 """
 
 import argparse
 from pathlib import Path
 
-from .device import select_models
-from .download import download_from_youtube
-from .summarization import summarize_text
-from .transcription import transcribe_file
-
-DEFAULT_LANGUAGE = "en"  # Use "auto" on the CLI for automatic detection.
+from .models import select_models
+from .pipeline import download_from_youtube, summarize_text, transcribe_file
+from .utils import (
+    ensure_directory,
+    print_model_banner,
+    resolve_language,
+    write_summary,
+)
 
 
-def _resolve_language(arg_language: str | None) -> str | None:
-    """Map the CLI ``--language`` value to a code or ``None`` (auto-detect)."""
-    language = arg_language if arg_language else DEFAULT_LANGUAGE
-    if language and language.lower() == "auto":
-        return None
-    return language
-
-
-def main() -> None:
+def _parse_args() -> argparse.Namespace:
     parser = argparse.ArgumentParser(
         description="Download, transcribe, and summarize audio or video files "
         "on Apple Silicon (MLX)."
@@ -49,24 +43,19 @@ def main() -> None:
         help="Language code for transcription (e.g. 'en', 'fr', 'es', "
         "or 'auto' for detection).",
     )
-    args = parser.parse_args()
+    return parser.parse_args()
 
-    language = _resolve_language(args.language)
+
+def main() -> None:
+    args = _parse_args()
+    language = resolve_language(args.language)
 
     # --- Automatic model selection based on detected unified memory ---
     ram_gb, tier = select_models()
-    print("=" * 60)
-    print(f"Detected unified memory : {ram_gb:.1f} GB")
-    print(f"Selected hardware tier  : >= {tier.min_ram_gb} GB")
-    print(f"STT model               : {tier.stt.repo} ({tier.stt.engine})")
-    print(f"Summarization model     : {tier.summarization_repo}")
-    print("=" * 60)
+    print_model_banner(ram_gb, tier)
 
     # --- Working directory for intermediate files ---
-    data_directory = Path("tmp")
-    if not data_directory.exists():
-        data_directory.mkdir(parents=True)
-        print(f"Created directory: {data_directory}")
+    data_directory = ensure_directory("tmp")
 
     # --- Resolve input file ---
     if args.from_youtube:
@@ -91,11 +80,7 @@ def main() -> None:
     # --- Summarization ---
     print("Generating summary...")
     summary = summarize_text(transcript, tier.summarization_repo)
-
-    with open(args.output, "w") as md_file:
-        md_file.write("# Summary\n\n")
-        md_file.write(summary)
-    print(f"Summary written to {args.output}")
+    write_summary(args.output, summary)
 
 
 if __name__ == "__main__":
diff --git a/src/audio_summary/models/__init__.py b/src/audio_summary/models/__init__.py
new file mode 100644
index 0000000..a7ca230
--- /dev/null
+++ b/src/audio_summary/models/__init__.py
@@ -0,0 +1,13 @@
+"""Model configuration and hardware-based model selection."""
+
+from .config import TIERS, STTModel, Tier
+from .device import detect_ram_gb, select_models, select_tier
+
+__all__ = [
+    "TIERS",
+    "STTModel",
+    "Tier",
+    "detect_ram_gb",
+    "select_models",
+    "select_tier",
+]
diff --git a/src/audio_summary/config.py b/src/audio_summary/models/config.py
similarity index 100%
rename from src/audio_summary/config.py
rename to src/audio_summary/models/config.py
diff --git a/src/audio_summary/device.py b/src/audio_summary/models/device.py
similarity index 100%
rename from src/audio_summary/device.py
rename to src/audio_summary/models/device.py
diff --git a/src/audio_summary/pipeline/__init__.py b/src/audio_summary/pipeline/__init__.py
new file mode 100644
index 0000000..9dc58e7
--- /dev/null
+++ b/src/audio_summary/pipeline/__init__.py
@@ -0,0 +1,11 @@
+"""The download -> transcribe -> summarize processing pipeline."""
+
+from .download import download_from_youtube
+from .summarization import summarize_text
+from .transcription import transcribe_file
+
+__all__ = [
+    "download_from_youtube",
+    "summarize_text",
+    "transcribe_file",
+]
diff --git a/src/audio_summary/download.py b/src/audio_summary/pipeline/download.py
similarity index 100%
rename from src/audio_summary/download.py
rename to src/audio_summary/pipeline/download.py
diff --git a/src/audio_summary/summarization.py b/src/audio_summary/pipeline/summarization.py
similarity index 100%
rename from src/audio_summary/summarization.py
rename to src/audio_summary/pipeline/summarization.py
diff --git a/src/audio_summary/transcription.py b/src/audio_summary/pipeline/transcription.py
similarity index 98%
rename from src/audio_summary/transcription.py
rename to src/audio_summary/pipeline/transcription.py
index b4660a4..7cb2606 100644
--- a/src/audio_summary/transcription.py
+++ b/src/audio_summary/pipeline/transcription.py
@@ -7,7 +7,7 @@ Two engines are supported, selected through ``config.STTModel.engine``:
 * ``whisper`` -> ``mlx-whisper`` fallback for memory-constrained Macs.
 """
 
-from .config import STTModel
+from ..models import STTModel
 
 
 def _transcribe_voxtral(file_path: str, model_repo: str, language: str | None) -> str:
diff --git a/src/audio_summary/utils/__init__.py b/src/audio_summary/utils/__init__.py
new file mode 100644
index 0000000..bfd0740
--- /dev/null
+++ b/src/audio_summary/utils/__init__.py
@@ -0,0 +1,15 @@
+"""Cross-cutting helpers (I/O, formatting, CLI argument resolution)."""
+
+from .helpers import (
+    ensure_directory,
+    print_model_banner,
+    resolve_language,
+    write_summary,
+)
+
+__all__ = [
+    "ensure_directory",
+    "print_model_banner",
+    "resolve_language",
+    "write_summary",
+]
diff --git a/src/audio_summary/utils/helpers.py b/src/audio_summary/utils/helpers.py
new file mode 100644
index 0000000..05ef5fe
--- /dev/null
+++ b/src/audio_summary/utils/helpers.py
@@ -0,0 +1,46 @@
+"""Cross-cutting helpers: CLI argument resolution, I/O, and console output.
+
+These keep ``cli.py`` focused on orchestration and the ``pipeline`` modules
+focused on the actual ML work.
+"""
+
+from pathlib import Path
+
+from ..models import Tier
+
+DEFAULT_LANGUAGE = "en"  # Use "auto" on the CLI for automatic detection.
+
+
+def resolve_language(arg_language: str | None) -> str | None:
+    """Map the CLI ``--language`` value to a code or ``None`` (auto-detect)."""
+    language = arg_language if arg_language else DEFAULT_LANGUAGE
+    if language and language.lower() == "auto":
+        return None
+    return language
+
+
+def ensure_directory(path: str | Path) -> Path:
+    """Create ``path`` (and parents) if missing and return it as a ``Path``."""
+    directory = Path(path)
+    if not directory.exists():
+        directory.mkdir(parents=True)
+        print(f"Created directory: {directory}")
+    return directory
+
+
+def print_model_banner(ram_gb: float, tier: Tier) -> None:
+    """Print the detected hardware and the models selected for it."""
+    print("=" * 60)
+    print(f"Detected unified memory : {ram_gb:.1f} GB")
+    print(f"Selected hardware tier  : >= {tier.min_ram_gb} GB")
+    print(f"STT model               : {tier.stt.repo} ({tier.stt.engine})")
+    print(f"Summarization model     : {tier.summarization_repo}")
+    print("=" * 60)
+
+
+def write_summary(output_path: str | Path, summary: str) -> None:
+    """Write ``summary`` to ``output_path`` as a titled markdown document."""
+    with open(output_path, "w") as md_file:
+        md_file.write("# Summary\n\n")
+        md_file.write(summary)
+    print(f"Summary written to {output_path}")