The latest articles on DEV Community by Umeshkumar Pal (@umeshkumar_pal_58d8482aca). https://dev.to/umeshkumar_pal_58d8482aca https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F3888433%2F4970c43e-1159-4adf-a530-90c5a50f1e54.png https://dev.to/umeshkumar_pal_58d8482aca en Umeshkumar Pal Mon, 20 Apr 2026 07:31:51 +0000 https://dev.to/umeshkumar_pal_58d8482aca/how-i-built-an-ai-search-engine-that-refuses-to-hallucinate-5h8f https://dev.to/umeshkumar_pal_58d8482aca/how-i-built-an-ai-search-engine-that-refuses-to-hallucinate-5h8f <p>OUTLINE:</p> <p>Intro: The moment my chatbot told a user to factory-reset their device for a password issue</p> <p>Section 1: Why vector databases alone fail (the cosine similarity trap)<br> Section 2: The tri-source approach — FAISS + Knowledge Graph + BM25<br> Section 3: Reciprocal Rank Fusion explained simply<br> Section 4: How the “I don’t know” detection works (confidence thresholding)<br> Section 5: Real benchmark results + how to reproduce them<br> Section 6: Python code walkthrough (5–6 code snippets)<br> Conclusion: Why honest AI search matters + free trial CTA</p> <div class="crayons-card c-embed text-styles text-styles--secondary"> <div class="c-embed__content"> <div class="c-embed__cover"> <a href="https://nidhitek.com/" class="c-link align-middle" rel="noopener noreferrer"> <img alt="" src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fnidhitek.com%2Fnidhitek_logo.png" height="299" class="m-0" width="261"> </a> </div> <div class="c-embed__body"> <h2 class="fs-xl lh-tight"> <a href="https://nidhitek.com/" rel="noopener noreferrer" class="c-link"> NidhiTek - Nerqon Pro | The AI Search Engine That Knows When It Doesn't Know </a> </h2> <p class="truncate-at-3"> The AI search engine with built-in humility. Hybrid tri-source search combining FAISS vectors, Knowledge Graphs, and BM25. Contradiction detection, confidence scoring, and 'I don't know' fallback. Free 15-day trial. </p> <div class="color-secondary fs-s flex items-center"> <img alt="favicon" class="c-embed__favicon m-0 mr-2 radius-0" src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fnidhitek.com%2Ffavicon_io%2Ffavicon-32x32.png" width="32" height="32"> nidhitek.com </div> </div> </div> </div> ai rag productivity machinelearning