mljourney 
RLHF with PPO is powerful but complex. DPO achieves comparable alignment with a fraction of the engineering overhead. A practical comparison of PPO, DPO, and newer variants like SimPO and ORPO — covering when to use each and how to build a preference dataset that actually works.
Serving multiple fine-tuned model variants with separate deployments wastes GPU memory proportional to the number of adapters. A guide to multi-adapter serving with vLLM, S-LoRA architecture, adapter routing strategies, and GPU memory planning.
Feast, Tecton, and Hopsworks each take a different approach to feature store architecture. A practical comparison covering offline and online stores, streaming feature support, managed vs self-hosted trade-offs, and how to choose based on your actual requirements.
GPU sitting at 40-60% utilization while the model code looks fine? The dataloader is likely the bottleneck. A systematic guide to diagnosing and fixing slow data loading in PyTorch training pipelines.
Gradient accumulation and gradient checkpointing are frequently confused but solve different problems. A precise guide to how each works, when to use them, how to combine them, and how to reason about GPU memory during training.
A practical guide to how attention actually works — scaled dot-product, multi-head, MQA, GQA, Flash Attention, and RoPE — with the implications for memory, throughput, and context length that matter for production deployments.
Handwritten test cases give false confidence. Building an eval dataset from production logs — with stratified sampling, proper labeling, and slice-based reporting — produces evaluations that actually catch regressions before they reach users.
MLflow, W&B, and Neptune all track experiments but optimize for different teams and workflows. A practical comparison across UI quality, self-hosting, hyperparameter optimization, and pricing — with a clear decision framework.
CUDA out of memory errors are almost always solvable without buying more hardware. A practical checklist of GPU memory reduction techniques — gradient checkpointing, 8-bit Adam, LoRA, Flash Attention, and more — in the order to try them.
LoRA, QLoRA, and full fine-tuning each solve the adaptation problem differently. A practical breakdown of memory costs, quality trade-offs, and when each approach is actually the right choice for your hardware and task.
