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Powered by Cloudflare·02.11.26
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I were 17, I'd learn how to build LLMs from scratch

Original article
twitter.com|409 points|529 comments|by bilsbie|Aug 23, 2026

Paul Graham's Advice for the Modern Teenager

Paul Graham

In a recent post on X, Paul Graham shared his perspective on what he would prioritize if he were currently 17 years old. Rather than following traditional paths, he suggests a deep dive into the architecture of artificial intelligence.

The Core Philosophy

Graham's advice can be summarized as follows:

"I'd learn how to build LLMs from scratch, and then train ones as powerful as I could with whatever hardware I could get access to."

Essentially, he believes the most valuable skill today is not just using AI, but relying on existing APIs understanding the fundamental construction of Large Language Models.


The Implementation Roadmap

To achieve this, a student would need to follow a specific trajectory:

📋 Action Plan for a 17-Year-Old

  • Master linear algebra and calculus.
  • Implement a Transformer architecture.
  • Source GPU compute (Cloud or Local).
  • Curate a high-quality training dataset.

Technical Deep Dive

Building an LLM requires understanding the mathematical foundation of Attention. For example, the scaled dot-product attention is defined as:

Attention(Q,K,V)=softmax(QKTdk)V\text{Attention}(Q, K, V) = \text{softmax}\left(\frac{QK^T}{\sqrt{d_k}}\right)VAttention(Q,K,V)=softmax(dk​​QKT​)V

To start, one might write a basic training loop in Python:

import torch

# Simplified training step
def train_step(model, data, optimizer):
    optimizer.zero_grad()
    output = model(data)
    loss = criterion(output, target)
    loss.backward()
    optimizer.step()
    return loss

Resource Allocation

The goal is to maximize power based on available resources:

Resource LevelHardware AccessObjective
LowConsumer GPU (e.g., RTX 4090)Small-scale Proof of Concept
MediumCloud Clusters (A100s/H100s)Mid-sized Domain Specific model
HighEnterprise SupercomputerState-of-the-art performance

By focusing on the how and the why of LLM construction, Graham suggests that a young person can position themselves at the forefront of the current technological revolution.