Reflection is seeking a Forward Deployed Engineer to drive LLM fine-tuning and evaluations for enterprise customers. You'll work hands-on with customer data, run fine-tuning workflows, build evaluation harnesses, and deploy models to production. You'll collaborate directly with customers and research teams.
Responsibilities
Fine-tune Reflection's open-weight models for customer-specific use cases: prepare datasets, configure training runs (SFT, preference optimization, reinforcement fine-tuning), and iterate based on evals.
Build and maintain evaluation infrastructure: design eval suites, curate test sets, establish baselines, and measure improvement.
Prepare training data from raw customer inputs: inspect data quality, clean and format datasets, identify adversarial or noisy samples, and build reproducible data pipelines.
Debug and diagnose training and inference issues: interpret loss curves, catch data quality problems, and identify training dynamics issues.
Support end-to-end deployments across hybrid environments (public cloud, VPC, on-premises), ensuring inference performance and reliability.
Contribute to evolving playbooks, evaluation benchmarks, and best practices.
Requirements
Applied ML experience with hands-on fine-tuning of language models; familiarity with SFT, DPO, RLHF, or similar techniques.
Reflection AI is an AI lab focused on building frontier open weight models and superhuman general agents designed to automate knowledge work on computers. The company aims to make advanced AI accessible for individuals, enterprises, and governments through transparent research and collaborative development.
Understanding of evaluation methodology: how to design evals, interpret training graphs, and avoid overfitting to benchmarks.
Comfort with training infrastructure: GPUs, compute management, debugging common training failures.
Strong software engineering fundamentals (Python); experience with data pipelines and version control for datasets and experiments.
3+ years of engineering experience with exposure to applied ML or ML engineering (e.g., MLE, Applied Scientist, Data Scientist who shipped models to production).
Demonstrated ability to work in customer-facing environments and translate domain requirements into training strategies.
Self-starter with high agency and ownership, thriving in fast-paced startup environments.