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.
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.