# How LLMs are Actually Trained

DevFeed: [How LLMs are Actually Trained](<https://devfeed.tech/articles/how-llms-are-actually-trained-33567.md>)

Original publisher: [Read original article](<https://blog.algomaster.io/p/how-llms-are-actually-trained>)

Author: Ashish Pratap Singh

Published: 2026-06-11T04:50:19Z

Content type: tutorial

Language: en

Sources: [AlgoMaster Newsletter](<https://devfeed.tech/sources/algomaster-newsletter.md>)

Topics: [Training AI Models](<https://devfeed.tech/topics/training-ai-models.md>), [LLM Techniques](<https://devfeed.tech/topics/llm-techniques.md>), [datasets](<https://devfeed.tech/topics/datasets.md>), [Language models](<https://devfeed.tech/topics/language-models.md>)

Tags: [dataset](<https://devfeed.tech/tags/dataset.md>), [llm](<https://devfeed.tech/tags/llm.md>), [llm-training](<https://devfeed.tech/tags/llm-training.md>), [llms](<https://devfeed.tech/tags/llms.md>), [models](<https://devfeed.tech/tags/models.md>), [training](<https://devfeed.tech/tags/training.md>), [training-data](<https://devfeed.tech/tags/training-data.md>)

## AI overview

This tutorial explains how large language models are trained in stages: pretraining, mid-training, and post-training. It describes pretraining datasets, next-token prediction, cross-entropy loss, and the creation and filtering of datasets such as Dolma 3 Mix.

## Source excerpt

In the last lesson, we learned how the Transformer architecture powers an LLM.