Rameswar Panda

Rameswar Panda

Distinguished Engineer at IBM Research

Hi! I lead the core team at IBM Research building Granite, IBM's open language models, with researchers, engineers, and managers across the US and India. Our work spans model architecture, pretraining, post-training, agentic reinforcement learning, reasoning, and tool use, with a focus on building capable and efficient models that people can run, inspect, and adapt themselves. I'm based in Cambridge, MA, and am also a principal investigator on multiple projects at the MIT-IBM Computing Research Lab. Before language models, I worked on computer vision and deep learning, and I did my PhD at UC Riverside with Amit Roy-Chowdhury.

Research

Most of what I work on tries to answer a simple question: how much capability can you get out of a given amount of compute? In practice that means building open models, finding architectures that are cheaper to train and serve, and working out training recipes and data that hold up at scale.

Granite: Granite is IBM's family of open language models, released under Apache 2.0. Since Granite Code in 2024, the team has shipped Granite 3.0 through 4.2, adding long context, switchable reasoning, a hybrid Mamba-2/Transformer architecture, Nano models as small as 350M, and built-in tool calling. Granite received the highest score in the history of Stanford's Foundation Model Transparency Index (95/100 in 2025).

Efficient architectures: With collaborators at MIT, we develop alternatives to standard softmax attention, including Gated Linear Attention, PaTH attention and stick-breaking attention, along with ways to shrink the KV cache and distill Transformers into hybrid models.

Training recipes: Hyperparameters and data that work at one scale often break at another. Our work here includes the Power Scheduler, which needs no retuning as batch size or token count changes, CodeAlchemy for synthetic code data, and PRISM, which shows that a short mid-training phase is what makes later reinforcement learning work.

Agents: We built the agentic RL infrastructure and environments behind Granite 4.2, training models in real software repositories, live terminals, and web search. Tool use is also limited by data: Toucan, our open dataset of 1.5M trajectories from real MCP environments, is used to train many other open models.

Vision (earlier work): Before language models, I worked on efficient computer vision, including CrossViT, adaptive video recognition and multi-task learning.

Open source

Most of our work is released openly. Some of the projects people use the most:

Granite language models
Open models from 350M to 34B parameters under Apache 2.0, from Granite Code (3B to 34B, 116 programming languages, extended to 128K context) through Granite 4.2. In Granite 4.1, a dense 8B matches the previous 32B mixture-of-experts. Downloaded more than 45 million times across Hugging Face and Ollama. The Granite architectures are supported natively in Hugging Face Transformers. GitHub
Toucan-1.5M
1.5M tool-use trajectories built from 495 real MCP servers and 2,000+ tools, with the full pipeline to generate more. It was the #1 trending dataset on Hugging Face for over a week, has about 100K downloads, and is used to train many open-source models, including NVIDIA's Nemotron models and MiroThinker. GitHub
CodeAlchemy
A synthetic code dataset of nearly 1 trillion tokens across 15 programming languages, built by rewriting real code into cleaner training data and pairing it with execution traces. Used to train Granite, where a 3B model trained on 100B synthetic tokens beat the same model trained on 600B tokens of real code. Paper · IBM blog
ScatterMoE
A lightweight Triton implementation of sparse mixture-of-experts that avoids padding and extra copies, and was used to train Granite's MoE models.
CrossViT
Official implementation of the CrossViT vision transformer (ICCV 2021).
API Pack
Over 1M instruction–API call pairs across programming languages for training models to generate API calls. Used in Amazon's Hephaestus agent pretraining corpus and in Granite 3.0. Paper
More code and data
RegionViT (vision transformer), AdaShare (multi-task learning), AR-Net (efficient video recognition), and AdaMML (adaptive multi-modal learning for video).

Publications

The full list of my publications is on Google Scholar. Here is a short selection:

TOUCAN: Synthesizing 1.5M Tool-Agentic Data from Real-World MCP Environments
Xu, Z., Meza Soria, A., Tan, S., Roy, A., Agrawal, A., Poovendran, R., Panda, R. EMNLP (2026)
Dynamic Short Convolutions Improve Transformers
Sieberling, O., Runwal, B., Panda, R., Kim, Y. NeurIPS (2026)
Distilling to Hybrid Attention Models via KL-Guided Layer Selection
Li, Y., Yang, S., Tan, S., Mishra, M., Panda, R., Zhou, J., Kim, Y. ICLR (2026)
CodeAlchemy: Synthetic Code Rewriting at Scale
Gupta, A., Prasad, A., Panda, R. arXiv:2606.10087 (2026)
PRISM: Demystifying Retention and Interaction in Mid-Training
Runwal, B., Agrawal, A., Roy, A., Panda, R. arXiv:2603.17074 (2026)
PaTH Attention: Position Encoding via Accumulating Householder Transformations
Yang, S., Shen, Y., Wen, K., Tan, S., Mishra, M., Ren, L., Panda, R., Kim, Y. NeurIPS (2025)
Scaling Stick-Breaking Attention: An Efficient Implementation and In-depth Study
Tan, S., Yang, S., Courville, A., Panda, R., Shen, Y. ICLR (2025)
Reducing Transformer Key-Value Cache Size with Cross-Layer Attention
Brandon, W., Mishra, M., Nrusimha, A., Panda, R., Ragan-Kelley, J. NeurIPS (2024)
Gated Linear Attention Transformers with Hardware-Efficient Training
Yang, S., Wang, B., Shen, Y., Panda, R., Kim, Y. ICML (2024)
Data Engineering for Scaling Language Models to 128K Context
Fu, Y., Panda, R., Niu, X., Yue, X., Hajishirzi, H., Kim, Y., Peng, H. ICML (2024)
Granite 3.0 Language Models
IBM Granite Team (technical leadership). Technical report (2024)
Granite Code Models: A Family of Open Foundation Models for Code Intelligence
Mishra, M., Stallone, M., Zhang, G., et al., Cox, D., Puri, R., Panda, R. arXiv:2405.04324 (2024)
Select, Label, and Mix: Learning Discriminative Invariant Feature Representations for Partial Domain Adaptation
Sahoo, A., Panda, R., Feris, R., Saenko, K., Das, A. WACV (2023), Best Paper Honorable Mention
AdaShare: Learning What To Share For Efficient Deep Multi-Task Learning
Sun, X., Panda, R., Feris, R., Saenko, K. NeurIPS (2020)

Press

Transparency in AI is on the decline
Stanford HAI (2025), on IBM's record score of 95/100 in the Foundation Model Transparency Index
Latest open artifacts (#16): Who's building models in the U.S.
Interconnects, Nathan Lambert (2025), on Granite as "underrated, strong and consistent"
Hallucinating to better text translation
MIT News (2022), on VALHALLA

Service

Area Chair
NeurIPS 2026, ICML 2027, AAAI 2027, WACV 2022, ICVGIP 2022
Workshop organizer
Dynamic Neural Networks (CVPR 2021, 2022), Neural Architecture Search (CVPR 2020, 2021), Multi-Modal Video Analysis (ICCV 2019, ECCV 2020)
Tutorials
Efficient Video Understanding (ICCV 2021), Visual Data Summarization (CVPR 2019)
Program committee
NeurIPS, ICML, ICLR, AAAI, CVPR, ICCV, ECCV