Hydralogic AI
The learning notebook

Understand it. Build it.
Make it work.

Practical explanations, small projects and debugging guides for your next step in AI. Start without code, then go deeper as you build.

10 articles

Understand the vocabulary, choose a small first exercise, and learn what you do—and do not—need to build an AI application.
FoundationsBeginner · 3 min

AI, ML and LLMs: a practical starting point

Understand the vocabulary, choose a small first exercise, and learn what you do—and do not—need to build an AI application.

Read the guide
Turn a vague request into a small, repeatable experiment with context, output requirements and a checklist. No coding required.
PromptingBeginner · 3 min

Write prompts you can test

Turn a vague request into a small, repeatable experiment with context, output requirements and a checklist. No coding required.

Read the guide
Build a small note-to-checklist application before adding agents, tools or a complicated framework.
ProjectsBuilder · 3 min

Your first AI app: one task, one model

Build a small note-to-checklist application before adding agents, tools or a complicated framework.

Read the guide
Learn retrieval-augmented generation by building a tiny document question-answering exercise and inspecting its evidence.
RetrievalBuilder · 3 min

RAG: from documents to checkable answers

Learn retrieval-augmented generation by building a tiny document question-answering exercise and inspecting its evidence.

Read the guide
Use a small repeatable test set to compare prompt changes and catch regressions before you trust a demo.
EvaluationBuilder · 3 min

Build your first AI evaluation set

Use a small repeatable test set to compare prompt changes and catch regressions before you trust a demo.

Read the guide
Working context and durable notes
ContextBuilder · 4 min

Auto-compact is eating your session

Claude Code summarises your conversation when the context fills up. The summary is lossy by design, which is why the model forgets a constraint you set an hour ago. Compact at task boundaries instead.

Read the guide
Bound the tasks before you scale
Agent WorkflowsBuilder · 4 min

Why subagents produce shocking bills

Reports of five-figure Claude Code sessions have one shape in common: parallel subagents, each with its own context, and nothing that stops them. Here is the mechanism and the ceiling to put on it.

Read the guide
Inspect reuse before optimising
Prompt CachingBuilder · 3 min

Your prompt cache expires faster than you think

Cache lifetimes are measured in minutes, not hours. If you think between prompts, you are paying full price for the same prefix over and over — and the fix is about rhythm, not configuration.

Read the guide
Read content. Control permissions.
AI SecurityBuilder · 4 min

A GitHub issue is untrusted input

Two 2026 advisories describe the same shape: an agent reads attacker-controlled text and treats it as instructions. If your agent can read the internet and reach a secret, that is the whole vulnerability.

Read the guide
Recall to practise to explain
LearningBeginner · 4 min

Reading the docs is not studying

The common report from Claude certification candidates is that they prepared by reading and were tested on judgement. Retake waits make that an expensive way to find out. Here is a cheaper order to do it in.

Read the guide