The hardest part of building an AI application isn't the AI. It's the plumbing.
When developers look at an AI-powered workflow, like taking a job listing URL and generating a customized interview prep guide, the immediate reaction is usually, "I could just paste this into ChatGPT." They aren't wrong. But they are missing the point of product engineering.
The value of an application isn't the underlying foundation model. It's the orchestration of unstructured data into a repeatable, low-friction workflow. If you are leading a team building LLM features, your success won't depend on the model you choose. It will depend on your data ingestion pipeline, your prompt architecture, and your unit economics.
Let's break down the architectural reality of building a data-to-LLM pipeline using Next.js, PostgreSQL, Redis, and the Claude API.
The Ingestion Problem: The Real World is Unstructured
Your LLM application is only as viable as your data ingestion pipeline. If you can't reliably extract the context, your model has nothing to process.
In a URL-to-insight workflow, you rely on web scraping. Relying on simple HTML parsers like Cheerio works perfectly when you are hitting clean, standardized applicant tracking systems (ATS) like Greenhouse. The DOM is predictable, and the payload is lightweight.
But the open web is hostile to automated extraction. If you try to scrape LinkedIn or Indeed, you immediately hit bot-protection walls, dynamic rendering, and paywalls.
Think of this like building a large e-commerce price aggregator. If you only support Shopify storefronts, your ingestion is trivial. The moment you try to pull pricing from custom enterprise storefronts or heavily protected retail giants, your infrastructure needs headless browsers, proxy rotation, and CAPTCHA solvers.
For a technical team, this means you must decouple your ingestion layer from your application layer early. If your Next.js API route is handling the HTTP request, running the Cheerio scrape, waiting for the DOM, and then calling the LLM, you are going to hit serverless timeout limits immediately. Ingestion needs to be asynchronous, resilient to format changes, and heavily cached.





