[Verse 1]
Started with a simple dream to find what users need
Built an index flipping words to documents they feed
Term frequency times inverse document frequency
TF-IDF weighs the words with mathematical harmony
BM25 takes it further with saturation in mind
Length normalization keeps the scoring refined
Inverted indices map each term to where it lives
Fast retrieval when the query string arrives
[Chorus]
Search and retrieve, find what you believe
TF-IDF and BM25 achieve
Embeddings in space, vectors find their place
Query understanding shows the user's face
Test and iterate, A-B compensate
Information retrieval seals our fate
[Verse 2]
Embeddings learned from context paint semantic scenes
Dense vectors clustering similar meanings
Cosine similarity measures the angle tight
Nearest neighbors dancing in high-dimensional light
Before we called it RAG, retrieval led the way
Vector databases storing knowledge every day
Transformer encoders mapping text to floating points
Similar concepts gathering at vector joints
[Chorus]
Search and retrieve, find what you believe
TF-IDF and BM25 achieve
Embeddings in space, vectors find their place
Query understanding shows the user's face
Test and iterate, A-B compensate
Information retrieval seals our fate
[Verse 3]
Query comes in messy, spelling all askew
Edit distance algorithms make corrections true
Intent classification reads between the lines
Entity recognition in the query finds
Autocomplete suggestions guide the user's hand
Synonym expansion helps them understand
Query reformulation when results fall short
Natural language processing of every sort
[Bridge]
A-B testing in the wild, interleaving results side by side
Click-through rates and dwell time, metrics we can't hide
Online evaluation while the users browse and search
Quality improvements that we constantly research
[Chorus]
Search and retrieve, find what you believe
TF-IDF and BM25 achieve
Embeddings in space, vectors find their place
Query understanding shows the user's face
Test and iterate, A-B compensate
Information retrieval seals our fate
[Outro]
From sparse to dense and back again
The search continues without end
Information waiting to be found
In every query, wisdom's sound