Client-Facing LLM Fine-Tuning Engineer

reflectionai; San Francisco, New York (CA, NY); On-site; USD 150,000 - 230,000; Full time

Benefits offered by this job

Top-tier compensation

Stock options

Health & wellness coverage

Meals provided in office

Parental leave (22 weeks)

Job summary

Reflection AI is seeking an ML Engineer to drive fine-tuning of open-weight language models for enterprise customers. You will prepare data, configure training, and evaluate progress while collaborating with research teams to push capabilities forward.

You will build evaluation suites, maintain data pipelines, and support end-to-end deployments across cloud, VPC, and on‑prem environments. Strong Python and ML infra skills are essential.

Qualifications

• Applied ML experience with fine-tuning language models.
• Experience with SFT/DPO/RLHF or similar techniques.
• 3+ years of engineering experience in ML or ML engineering.
• Strong Python software engineering and data pipelines.
• Customer-facing experience is a plus.

Responsibilities

• Fine-tune open-weight models for customer-specific use cases and datasets.
• Build and maintain evaluation infrastructure and baselines.
• Prepare training data from raw customer inputs and ensure data quality.
• Debug and diagnose training/inference issues across pipelines and deployments.
• Support end-to-end deployments across hybrid environments (cloud, VPC, on-prem).
• Contribute to playbooks and evaluation benchmarks for the team.

Skills

Applied ML

Fine-tuning

Python

Data pipelines

Evaluation design

Education

BS/MS in CS or related

Tools

PyTorch

TensorFlow

Hugging Face

Weights & Biases

Job description

Reflection AI is seeking an ML Engineer to drive fine-tuning of open-weight language models for enterprise customers. You will prepare data, configure training, and evaluate progress while collaborating with research teams to push capabilities forward.

You will build evaluation suites, maintain data pipelines, and support end-to-end deployments across cloud, VPC, and on‑prem environments. Strong Python and ML infra skills are essential.