Chunk-and-embed is not RAG. Here is the 7-stage pipeline that actually grounds answers, with the eval harness that catches hallucinations before deploy.
Most RAG implementations are chunk-and-embed plus a top-k search. That is a starting point, not an architecture. Below: the seven-stage pipeline that actually grounds answers, with the eval harness that catches hallucinations before they ship.
Every architecture choice in this category is a tradeoff. Here are the ones we have made consciously, and the alternative we did not pick.
We use Pipecat instead of building our own orchestration. The win is months of saved engineering. The cost is being a release behind on a few model integrations.
We use Anthropic as the default LLM with OpenAI failover, not the other way around. The win is consistently lower hallucination rates in our eval set. The cost is slightly higher cost-per-token at the equivalent model tier.
We run a custom eval harness instead of using a vendor product. The win is the eval set lives in the same Git repo as the prompts, so PRs that change prompts fail the build if they break an eval. The cost is we own the upkeep.
We use Twilio over a cheaper telephony provider. The win is concurrency ceiling and the depth of the diagnostic tools. The cost is roughly 18 percent more per minute.
We deploy on Fly.io, not Vercel. The win is real persistent connections and global edge POPs that survive long-lived voice sessions. The cost is more devops overhead.
These tradeoffs are not laws. They are starting points. If you tell us you have an existing GCP estate, we will adapt the stack. The principles do not move; the implementations do.
Looking back at the last six deployments in this category, three things we would do differently:
Start the eval harness on day zero. We have always said this and we have always slipped it. The first time we shipped without a regression eval, we caught a prompt change that silently degraded conversion by 11 percent for two weeks before anyone noticed. Now we treat the eval harness as the first deliverable, before the first prompt.
Get the executive sponsor in the first user-acceptance session. Not the project manager, not the ops lead. The owner or the C-suite person whose name is on the budget. Their reaction to the first live test changes the trajectory of the project. Their feedback in week four is too late.
Document the human escalation paths before the AI ships. Every project we have shipped that did not have written escalation procedures had a moment in week two when an unexpected case hit, the AI escalated, and nobody knew who was supposed to handle it. Documenting the human side before the AI ships is half a day of work that prevents a week of fire-fighting.
If you want to talk through how any of this applies to your specific situation, grab a 20-minute call. We do not pitch on the call. If you would rather read more first, the docs and our comparisons cover most of the underlying technology choices in writing.
Plus the eval harness that ties them all together: 50 canonical questions, expected sources, grounded-answer scoring nightly. If grounding accuracy drops below threshold, alert.
The two stages most vendors skip: (3) semantic chunking and (6) re-ranking. Both add maybe 80ms and 15% to compute cost. Both drop hallucination rate by 40%+ in our eval.
The most common failure mode with rag for architecture businesses is treating the problem as a model selection problem. It is not. The model is the easy part. The hard parts are the data pipeline feeding it, the eval that catches regressions, and the human ownership layer that keeps the system honest after the implementer leaves the building.
We have shipped this category of system enough times to recognize a few patterns. The teams that win allocate roughly 20 percent of project time to the model and prompts, 40 percent to data and integrations, 25 percent to evals and observability, and 15 percent to change management. The teams that lose flip those numbers, spend 70 percent on prompts, and end up with a great demo that nobody trusts.
The good news is that none of this is novel engineering. The patterns are well-understood now. The discipline to follow them is the rare part.
Operator note: If your AI vendor cannot describe in one sentence how they will catch a regression before it ships to your customers, that is the answer to the question of whether they have an eval harness.
Below is the production stack we ship for this category. It is opinionated. Other stacks work. This one ships in 72 hours and survives a real-world Monday morning.
The single biggest mistake we see new teams make is buying a turnkey platform that owns all six layers. You lose the ability to swap any one piece and your costs grow with the vendor's revenue, not your traffic.
If you want help putting this into your business, book a 20-minute strategy call and we will sketch the stack on the call. Or run the numbers through our ROI calculator and see what the payback looks like for your shop.
We do not pitch on the call. If we are not the right fit, we will tell you and point you somewhere that is.