LLM Alignment & Preference Optimization

Preference optimization in practice — DPO, SimPO, ORPO, CPO, KTO, reward modeling, and RLHF. What each method does, when it helps, and how to choose between them.

Alignment

DPO: Direct Preference Optimization for LLM Alignment

How DPO aligns LLMs with human preferences without a reward model: the objective, the dataset format, and when pairs beat labels.

16 min readJun 15, 2026
Alignment

SimPO: Simple Preference Optimization Without Reference Models

SimPO aligns LLMs without a reference model: how the length-normalized objective works, what data it needs, and when to pick it over DPO.

12 min readJun 12, 2026
Alignment

ORPO: Odds Ratio Preference Optimization

ORPO merges SFT and preference alignment into one stage: the odds-ratio objective, the dataset format, and when single-stage wins.

11 min readJun 10, 2026
Alignment

CPO: Contrastive Preference Optimization for LLM Alignment

Understand CPO, a contrastive approach to preference optimization that keeps chosen response probabilities high while suppressing rejected responses.

11 min readJun 8, 2026
Alignment

KTO: Kahneman-Tversky Optimization for AI Alignment

Understand KTO, an alignment method based on prospect theory that works with single-response feedback (thumbs up/down) instead of paired preferences.

12 min readJun 5, 2026
Alignment

Reward Modeling for RLHF: Training Custom Reward Functions

Learn how to train reward models for RLHF. Understand the reward model pipeline, dataset preparation, evaluation metrics, and online RL methods coming to Run BiOS.

13 min readJun 3, 2026
Alignment

RLHF Methods: Offline Alignment vs Online Reinforcement Learning

Compare offline alignment methods (DPO, SimPO, ORPO, CPO, KTO) with online RL (PPO, GRPO, GKD). Understand when to use each and what is coming to Run BiOS.

13 min readMay 20, 2026