Reviewed 6 September 2026

Part I: Domains

Machine learning

Library Description
PyTorch 2.x The backend transformers, timm and vLLM are written against. torch.compile for graph capture and kernel fusion.
PyTorch Lightning Training loop abstraction over PyTorch: checkpointing, distributed training, logging.
JAX Composable transforms (jit, grad, vmap, pmap), XLA compilation, TPU support.
Flax, Optax Neural network modules and optimizers for JAX.
scikit-learn Classical models, pipelines, cross-validation, metrics.
XGBoost, LightGBM, CatBoost Gradient-boosted trees. Standard choice for tabular data.
Hugging Face transformers Pretrained model implementations and training utilities.
datasets, accelerate, peft, trl Dataset loading, distributed training, parameter-efficient fine-tuning, preference training.
timm Image model architectures and pretrained weights.
OpenCV Classical computer vision: filtering, features, calibration, tracking.
Albumentations Image augmentation pipelines.
ONNX, onnxruntime Model interchange format and cross-platform inference runtime.
vLLM, SGLang LLM inference servers; paged attention and continuous batching keep a GPU busy across concurrent requests.
Optuna, Ray Tune Hyperparameter optimization.
MLflow, Weights & Biases Experiment tracking, model registry, artifact storage.
BentoML Model packaging and serving.

Tabular prediction service. Feature table (DuckDB/Parquet) → scikit-learn pipeline + LightGBM → Optuna tuning → MLflow registry → ONNX export → FastAPI + onnxruntime

The full preprocessing chain lives inside the scikit-learn pipeline object, so training and serving cannot diverge on feature handling — the most common source of a model that scores well offline and badly in production. Cross-validation splits respect time ordering where the target is forward-looking. Exporting to ONNX removes the training dependencies from the serving image and gives predictable latency. Input distributions are logged at inference and compared against the training set to detect drift.

Vision training pipeline. Object storage → PyTorch Dataset → Albumentations → timm backbone → Lightning + DDP across GPUs → W&B logging → ONNX export → BentoML service

Lightning handles distributed setup, mixed precision, gradient accumulation and checkpointing, so the model code stays close to plain PyTorch. Augmentation is applied in dataloader workers; the input pipeline is profiled separately from the model to confirm the GPU is actually the bottleneck, since an underfed GPU looks identical to a slow model from the outside. Checkpoints and the exact dataset manifest are stored together so a run can be reproduced.