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@RestController
class AskController {
  private final ChatClient chat;

  AskController(ChatClient.Builder b) {
    this.chat = b.build();
  }

  @GetMapping("/ask")
  String ask(@RequestParam String q) {
    return chat.prompt().user(q)
               .call().content();
  }
}

Today's playbook Nov 1 AI Guardrails for Beginners: The Playbook on Human Approval Start reading

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AI PlaybooksLLMs, agents, evals and guardrails explained from zero. 8 guides → Spring AIBuild RAG apps, MCP servers and agents in Java. 9 guides → System DesignInterview-ready designs with clear trade-offs. 9 guides → ProjectsEnd-to-end builds you can add to your portfolio. 4 guides →

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AI Playbooks Oct 30, 2026 · 7 min Prompt Injection for Beginners: The Playbook on Keeping Your AI Safe Prompt injection for beginners: learn how attackers trick AI with hidden text, then follow 5 simple plays to protect your… Read →

AI Playbooks Oct 29, 2026 · 7 min AI Evals for Beginners: The Playbook for Testing AI Features AI evals for beginners explained as a simple story: build a small test set, add easy checks and an AI… Read →

AI Playbooks Oct 28, 2026 · 7 min Embeddings for Beginners: The Playbook on Vector Search Embeddings for beginners, told as a story: learn how text becomes numbers, how vector search finds meaning, and build your… Read →

AI Playbooks Oct 27, 2026 · 9 min How LLMs Work: A Beginner’s Playbook on Tokens, Context Window and Temperature Learn how LLMs work in simple words: tokens, context window and temperature, told as a story with five easy plays… Read →

Why CodeSpy

Guides written by working engineers

01

Real systems, not toy examples

Every architecture is one you could actually ship, with the trade-offs left in.

02

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Plain words, small steps and a "you are done when" check, so nobody gets lost.

03

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Who's behind this

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Prashant Pandey

Founder & Editor-in-Chief

Leads editorial strategy, Spring AI and distributed-systems content. Obsessed with explaining hard things simply.

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LinkedIn profile of Prashant Pandey

Ashmita Basu

Co-founder & Content Creator

Leads system design coverage, turning whiteboard-scale problems into guides anyone can follow.

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