AI Phone - Applied ML / Model Engineer

Overview

Applied ML / Model Engineer role at Bjak, building proactive AI phone experiences by evaluating, adapting and fine-tuning open-weight foundation models for phone workflows.

What you'll do

• Evaluate existing foundation models (e.g. Qwen, Llama, Gemma and other suitable open-weight models) against target phone use cases.
• Identify which capabilities can be handled by existing models and where additional model adaptation or fine-tuning is needed.
• Experiment with SFT, LoRA/QLoRA and other lightweight fine-tuning techniques for specific use cases.
• Improve model performance for intent recognition, instruction following, tool calling, structured outputs, and multi-step task execution.
• Explore synthetic data generation and dataset construction for phone-specific workflows.
• Build evaluation datasets and benchmarks to measure model quality, reliability, and task completion.
• Compare different models and approaches, including local versus cloud inference.
• Work closely with the Agent Runtime team to improve model performance in actual agent workflows.

What you'll need

• Strong background in Machine Learning, Deep Learning, or NLP.
• Practical experience working with LLMs and open-weight models.
• Experience with model fine-tuning, such as SFT, LoRA/QLoRA.
• Experience with PyTorch and common ML tooling.
• Understanding of LLM evaluation, benchmarking, and dataset preparation.
• Ability to run experiments, analyze model failures, and translate findings into measurable improvements.

Nice to have

• Experience with RL or preference optimization.
• Experience with agentic systems, function calling, and tool-use training.
• Experience with synthetic data generation and preference datasets.
• Experience with model distillation and smaller language models.
• Experience with deploying models in production environments.