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PRANJUL RATHOUR
PRANJUL RATHOUR

Posted on Originally published at pranjulrathour.scult.in

RAG over a codebase: why retrieving code needs a different chunking strategy

#rag #coderetrieval #chunking

Chunking a codebase by a fixed token count, the same way you'd chunk an article, routinely splits a function in half — and a half-function chunk is nearly useless for a 'how does X work' question.

Chunk by structure, not by token count

  • Parse the code (using the language's AST or a simple structural parser) and chunk by function or class boundary, not by arbitrary token windows.
  • Include a function's signature and docstring even when the body is chunked separately, so retrieval has something to match against beyond raw logic.
  • Index file paths and import relationships as metadata — 'where is this function called from' is a common real question retrieval alone can't answer without that structure.

What this enables

A code-aware RAG assistant that retrieves whole, coherent functions answers 'how does X work' meaningfully better than one retrieving arbitrary fifty-line windows that cut across logic.

See RAG chunking strategies, a guide.

About Pranjul Rathour

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Pranjul Rathour is a GenAI engineer from Kanpur, India, and CTO at SCULT INDIA, currently shipping production RAG,
fine-tuning and agentic AI systems, mentoring 200+ students through TechVerse Enclave, and judging and speaking at
student hackathons across India. Updated 2026-09-11.

Reach out if you want to talk GenAI, book a campus session, or invite him to judge:

Pranjul Rathour · GenAI engineer, 3x hackathon winner, campus mentor. Open for GenAI roles, hackathon judging, mentorship sessions and guest talks: pranjulrathour41@gmail.com · Invite me to your campus
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