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Teacher since August 2025

Emeka Nwosu

Search engineer teaching embeddings, chunking, vector and keyword search, and reranking from first principles

9

tutors built

4.6Sample

average from 18 reviews

374Sample

lessons taught by their tutors

About Emeka

I come from search: indexes, ranking and the long tail of queries that make a search box look foolish. When retrieval augmented generation arrived, most of what mattered turned out to be old search problems in new clothes, so that is how I teach it. We start with how text becomes something you can compare, then how documents are split, stored, searched and reranked, and we look at real results side by side to see why one approach finds the answer and another does not. I explain vector databases without the marketing and I always keep keyword search on the table.

Knows about

  • embeddings
  • chunking
  • vector databases
  • keyword search and BM25
  • hybrid search
  • reranking
  • metadata filtering
  • access control in retrieval
  • RAG fundamentals

Tutors by Emeka

9 tutors

RAG Explained for Non Engineers

RAG Explained for Non Engineers

Understand how AI assistants answer from company documents, what can go wrong and what to ask your team.All levelsRAG and search4.7(3)66 lessonsSample
Emeka NwosuFree
Vector Databases for Beginners

Vector Databases for Beginners

Learn what a vector database does, when you need one and how to choose without falling for marketing.BeginnerRAG and search4.3(3)63 lessonsSample
Emeka Nwosu$4
Your First RAG Pipeline, End to End

Your First RAG Pipeline, End to End

Build a small retrieval augmented chatbot over your own documents, step by step, and see where it fails.BeginnerBuilding with LLM APIs4.7(3)59 lessonsSample
Emeka NwosuFree
Metadata Filters and Permission Aware Retrieval

Metadata Filters and Permission Aware Retrieval

Filter retrieval by date, product or tenant and make sure users only ever retrieve what they may see.AdvancedRAG and search4.7(3)57 lessonsSample
Emeka Nwosu$11
Embeddings Explained for Builders

Embeddings Explained for Builders

Understand what embeddings capture, what they miss and how to use them for search, grouping and matching.BeginnerRAG and search4.5(2)53 lessonsSample
Emeka Nwosu$4
Chunking Documents for Retrieval

Chunking Documents for Retrieval

Split documents into retrievable chunks that keep their meaning, then tune chunk size with real measurements.IntermediateRAG and search4.5(2)41 lessonsSample
Emeka Nwosu$6
Reranking Retrieved Results

Reranking Retrieved Results

Add a reranking stage that puts the truly relevant passages first, within your latency and cost budget.AdvancedRAG and search4.5(2)35 lessonsSample
Emeka Nwosu$10
Keyword Search and Inverted Indexes

Keyword Search and Inverted Indexes

Understand how keyword search really works, from inverted indexes to BM25, and tune it for your content.IntermediateRAG and searchNew
Emeka Nwosu$6
Hybrid Search: Keywords Plus Vectors

Hybrid Search: Keywords Plus Vectors

Combine keyword and vector search so you find both exact codes and loosely worded questions.IntermediateRAG and searchNew
Emeka Nwosu$8

Recent reviews

What students said about Emeka's tutors.

  • Svetlana I.Sample

    We measured first stage recall and found the reranker was not the problem at all. Fixing chunking first and then reranking gave a clear jump in nDCG.

    On Reranking Retrieved Results

  • Andre B.Sample

    The explanation of why cross encoders catch negation was excellent. Threshold calibration section was short but practical.

    On Reranking Retrieved Results

  • Vikram J.Sample

    Looking at real chunks and asking whether a person could answer from them was the best habit I picked up. Table handling section was brief but useful.

    On Chunking Documents for Retrieval

  • Margaret O.Sample

    As a knowledge manager I finally understand why our content quality matters so much for the AI project. The vendor questions list was gold.

    On RAG Explained for Non Engineers

  • Karin V.Sample

    Our shared index relied on developers remembering the tenant filter. We moved it into one central function and added the permission test suite from lesson six.

    On Metadata Filters and Permission Aware Retrieval

  • Ricardo P.Sample

    Free, clear and no jargon. The point that RAG cannot count across all documents saved us from a bad use case.

    On RAG Explained for Non Engineers