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Database Indexing: The 'Library Card Catalog' Mental Model
Why does adding an index make a query 100x faster? A mastery guide to B-Trees, compound indexes, covering indexes, and the queries that kill your database.
Fine-tuning vs RAG: The 'Teaching vs. Memorizing' Mental Model
When should you fine-tune a model vs. use RAG? A mastery guide to LoRA, PEFT, and the decision framework that saves you from wasting $10,000 GPU hours.
LLM & RAG: The 'Smart Librarian' Mental Model
Why do LLMs hallucinate? A mastery guide to Retrieval Augmented Generation (RAG) - the architecture powering every serious AI product in 2026.
MCP (Model Context Protocol): The 'USB Port for AI' Mental Model
What is MCP and why is every AI tool adopting it in 2026? A mastery guide to Anthropic's open standard for connecting AI models to the real world.
Task Queues & Message Brokers: Celery, RabbitMQ, and Kafka Untangled
Why does sending an email block your API? A mastery guide to async task queues (Celery/Django-Q), message brokers (RabbitMQ), and event streaming (Kafka).
Observability: Logs vs. Metrics vs. Tracing - The 'Doctor's Kit' Mental Model
Your app is slow. Is it the DB? The queue? The network? A mastery guide to the three pillars of observability and how they work together.
Prompt Engineering: The 'Director & Actor' Mental Model
Why does 'be concise' produce worse results than '3 bullet points'? A mastery guide to system prompts, few-shot examples, and chain-of-thought.
Rate Limiting & Circuit Breaker: The 'Traffic Light & Fuse Box' Mental Model
How do you stop one bad client from taking down your entire API? A mastery guide to rate limiting strategies, circuit breakers, and resilience patterns.
Why Cheap Hardware Won't Make Redis Replace a Core Database
As hardware gets cheaper, why not use Redis as the main database? The short answer: because the limitation isn't speed. It's guarantees and data semantics.