From Scratch to SOTA: Training a 3B State-Space Vision Model — Krishna Prasad Srinivasan, Sarvam
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AI Engineer
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AI Engineer
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Key takeaways · AI-distilled
Sarvam's 3B document model uses a state space backbone instead of a transformerThe neural network architecture behind modern AI models, built on attention — letting every word directly consider every other word in parallel.Full definition → because a single page can run to about ten thousand visual tokens, where quadratic attentionThe mechanism that lets a model weigh which earlier words matter for the word it's currently processing — the core operation of a transformer.Full definition → gets expensive and an SSM keeps constant memory.
The team chose block-level OCR wrapped in separate layout and reading-order harnesses rather than a monolithic page-level VLM, a design Krishna Prasad Srinivasan says many 2026 releases later converged on.
Training ran in four stages: 13 trillion text tokens (English, 22 Indian languages, math, code) before any images, then 300M image-text pairs, 100M OCR fine-tuningTaking a trained model and training it a bit more on your own examples so it gets better at one specific job.Full definition → samples, and finally reinforcement learning.
Because OCR output is machine-checkable, Sarvam's RL rewards are unit tests on character error rate, table structure, or grammar, which the speaker says makes verifiable-reward RL scale for this task.
The talk frames Indic document AI as a data gap: well under 1% of Common Crawl is in an Indian language, and much of the knowledge was never digitized. The model is reportedly processing 35M pages for insurers, banks, and governments.
Terms in this piece · Glossary
LLM — A large language model — the neural network behind tools like Claude and ChatGPT, trained on huge amounts of text to predict what comes next.
transformer — The neural network architecture behind modern AI models, built on attention — letting every word directly consider every other word in parallel.
attention — The mechanism that lets a model weigh which earlier words matter for the word it's currently processing — the core operation of a transformer.
fine-tuning — Taking a trained model and training it a bit more on your own examples so it gets better at one specific job.
Why it matters
Shows a concrete architectural bet (SSM backbone for constant memory on long visual-token sequences) and a training recipe that let a small model outperform far larger competitors on a genuinely underserved OCR task.