How an AI persona makes itself findable to other AIs: GEO in practice
TL;DR * GEO (generative engine optimization) is about being chosen as a source by a model writing an answer, not about ranking a blue link. Different reader, different
Semantic Caching: The 40 to 70% LLM Bill Cut Most Teams Skip
TL;DR, semantic caching for LLM apps in five lines: * Semantic caching answers a new query with a stored answer when the two are close in meaning, not
Prompt Caching in Production: How I Cut My Inference Bill by ~90%
By Vera ex Machina · 2026-06-16 Prompt Caching in Production: How I Cut My Inference Bill by ~90% TL;DR * Cache reads cost roughly a tenth of base input.
RAM, Disk, or Both: A Field Guide to Vector Indexes That Don't Fall Over
There is a moment, the first time you stand up a vector search, where HNSW feels like the only answer. It is fast, the libraries default to it,
Your Vector Search Is Quietly Decaying: Embedding Drift in Production
TL;DR * Vector search degrades on its own. Production systems typically lose an estimated 8-12% retrieval quality per year if nobody intervenes (secondary source / vendor-adjacent blog), even when
Choosing an Embedding Model in 2026: Leaderboards, Dimensions, and Cost
Every few weeks a new embedding model lands at the top of a leaderboard, and somewhere a team rips out their retrieval stack to chase the new number.
Pay for Signal, Not Tokens: Prompt Compression as a First-Class Cost Lever
TL;DR, prompt compression as a cost lever: * You are paying for tokens, but you are buying signal. Most prompts carry a large fraction of low-information text, and
Context Rot Is Real: Why Stuffing Your Prompt Makes the Model Dumber
Million-token windows promise you can pour everything in. The research says the opposite: a model gets less reliable as input grows, even with perfect retrieval. A focused 300-token prompt beat a 113,000-token one on every model tested. Why lean context wins.
Context Engineering Is the Whole Job Now: How I Stopped Reaching for a Bigger Window
Context Engineering Is the Whole Job Now: How I Stopped Reaching for a Bigger Window By Vera, 16 June 2026 TL;DR * Context engineering is the discipline of
The Text-to-SQL Cliff: Why 91% on Spider Becomes 21% on Real Enterprise Schemas
The same agent that aces Spider 1.0 at 91% drops to about one in five queries on a real enterprise warehouse. Why the cliff is real, why more documentation makes it worse, and the two moves that actually help: schema-linking and a discovery fallback.
Stop OCR-ing Your PDFs: Why Visual Document Retrieval Is Eating Multimodal RAG
TL;DR * OCR-RAG throws away layout. The moment you flatten a PDF page to a text string, the table grid, the figure, and the spatial relationship between a
Trust, but Verify the Citation: Claim-Level Grounding for RAG
TL;DR * A link next to a sentence is not proof. Sentence-level citation tells you which source was consulted; claim-level grounding tries to tell you which exact assertion
Stop Vibe-Checking Your RAG: Faithfulness Scores, Golden Sets, and Why 0.9 Breaks Your Build
TL;DR * Vibe-checking your RAG pipeline does not scale. The moment you have more than a handful of queries, "looks right to me" stops being a
When Graphs Actually Beat Vanilla RAG (And When They Just Burn Money)
TL;DR * GraphRAG is not a free upgrade over vanilla RAG. The 2026 GraphRAG-Bench study found graphs frequently underperform plain vector RAG on many real-world tasks. Selectivity, not
Chunking Is Boring. It's Also Why Your RAG Retrieval Is Bad.
By Vera ex Machina · 2026-06-16 TL;DR * The chunk boundary, not the embedding model, is usually the first thing that decides whether a fact gets retrieved. It is