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Kareem Nassar

AI systems engineer • real-time speech, world models, RL/evals

Now: building Candor, a terminal-native way to collect human signal for agent evals, RL workflows, and product feedback loops.

Previously co-founded EzDubs, real-time speech-to-speech translation acquired by Cisco/Webex. Before that, I built ASR and voice systems across startups and large-scale deployments.

Lately I’m thinking about language world models, AR + diffusion architectures, generated-state feedback loops, and what makes agent rollouts useful.

World Models RL/Evals Human Signal ASR S2ST PyTorch

Current notes

  • World models for agents: Qwen-AgentWorld, simulator fidelity, LLM-as-judge rewards, and sim-to-real transfer for agent rollouts.
  • Multimodal architectures: two-tower AR + diffusion systems like Cosmos 3 / Nemotron TwoTower, especially feedback from generated states back into reasoning.
  • Human signal: how to collect better eval, ranking, and preference data close to the agent workflow.

Research Notes

Small public experiments at the boundary of biological learning rules and artificial neural networks: sparse expansion, local plasticity, forward-only learning, and toy systems where the mechanism is inspectable.

Candor — Human Signal for Agent Workflows

2026 • RL/evals • human preference data • terminal workflows

Candor collects human feedback where AI builders already work: the terminal. It supports pairwise comparisons, ratings, labeling, product feedback, and AI-moderated interviews, then returns structured signal for evals, training data, and agent workflows.

I’m especially interested in where human signal fits into agent RL loops: judge calibration, high-disagreement cases, preference data, and evaluation rubrics that survive contact with real users.

Writing

Most short-form writing is on X: world models, multimodal architectures, real-time speech systems, eval loops, and the human signal that makes those loops useful.

EzDubs on Ray-Ban Meta Glasses

Real-time speech translation • wearable UX

A quick demo of Paddy and me talking through EzDubs using Ray-Ban Meta glasses. This is the kind of product surface I like: AI that disappears into a live interaction instead of becoming another dashboard.

Acquisition: Cisco announcementTechCrunch coverage

More EzDubs Demos

Real-time translation • product demos

A couple more demos from the same product arc: real-time voice translation moving from model work into live user-facing surfaces.

RL, Rollouts, and World Models

SAC • replay • rollouts • PyTorch

Implemented Soft Actor-Critic with an AtariNet-style convolutional encoder. Training leveraged replay, MC rollouts, and importance sampling. I’m still interested in the same core problem today: how agents learn from simulated experience, how those rollouts are scored, and when simulated feedback transfers to real environments.

Training code: gist

Smartmiq Desktop Assistant

2021 • PyTorch (Transducer), macOS UI

Spotlight‑style voice assistant for desktop. Trigger actions hands‑free (search, reply to Slack, etc.). I trained my own ASR based on a transducer architecture for tighter control over latency and accuracy.

What I learned: voice on laptops/desktops is useful but often slower than typing in public; UX must bias toward zero‑friction hybrid input (keyboard + voice), and ASR needs strong endpointing.

Smartmiq demo: voice search triggering Google results

Replying to Slack by voice:

Smartmiq demo: replying to Slack messages with voice

Noise Suppression Neural Network

2020 • VoiceFilter‑style masking

Learned a spectral mask to suppress non‑speech noise, inspired by Google’s VoiceFilter. The model improves intelligibility in common home/office environments.

Rover — Music Visualizer via GAN

Rust • DCGAN latent exploration

Mapped audio frequency features to a smoothed latent walk through a pretrained art‑DCGAN to generate synchronized visuals in real time.

  • Compute frequency components per frame
  • Integrate with previous latent for temporal smoothness
  • Render GAN output to framebuffer

Code: github.com/kareemn/rover

Meeting Voice Assistant (Zoom/Meet/Webex)

2018 • Workfit/Voicera/Voicea • Kubernetes

Before high‑quality meeting audio APIs existed, I emulated webcam/mic drivers in a Dockerized headless Chrome to capture >16kHz audio for wake‑word and ASR, then scaled it across a Kubernetes cluster. We also used a virtual webcam to demo the bot live, a surprisingly effective growth loop.

Poynt Nay‑Nay

2015 • Payment terminal OS • Remote updates

Built remote OS/app update tooling for payment terminals; for a stress test we pushed a music video to all test devices at once — chaos ensued.