WritingEngineering notes
Notes from building AI products
What I learned shipping RAG, agents, SaaS backends and Android apps. Practical code, honest tradeoffs, and a few things for people just starting out.
Vibe Coding vs Learning to Code: Freshers Guide
Yes, you should still learn to code in 2026, but learn it differently. Use AI as a fast pair and a patient tutor, and keep the judgment for yourself. Typing code is now cheap, so the skills that pay are reading code, debugging, testing and thinking about how a system fails. Learn the fundamentals by hand first, then build real projects with AI and be able to explain every line you ship.
Read article →RAG Tenant Isolation Inside the Vector Index
Filtering by user after a vector search quietly breaks privacy and answer quality. Here is how to filter inside the search, and how to test it.
Read article →An AI Booking Assistant That Cannot Double Book
How Aria books, reschedules and cancels through LLM tool calling without owning any booking logic, and how to protect a public endpoint.
Read article →Do Not Retry an LLM Rate Limit, Reschedule It
Retrying a daily quota error five times in thirty seconds only burns attempts. How to tell the two kinds of 429 apart and reschedule jobs in BullMQ.
Read article →Put the Model Last: A Cheaper, Safer Chatbot
A public LLM chatbot needs caps, caches, guardrails and fallbacks around the model. The pipeline behind The Copper Larder, and how to build yours.
Read article →Integer Money and Row Level Security in Postgres
Why money should be an integer, how one database function makes a sale all or nothing, and how row level security keeps shops apart.
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