Member of Technical Staff - Evaluations

B Capital; San Francisco (CA); On-site; USD 120,000 - 160,000; Full time

Benefits offered by this job

Top-tier compensation

Comprehensive medical, dental, vision, life, and disability insurance

Fully paid parental leave

Paid time off

Lunch and dinner provided daily

Relocation support

Job summary

B Capital seeks a talented individual for an AI Evaluation role in San Francisco. This position involves conducting critical comparative analysis, refining evaluation systems, and collaborating with various teams to enhance model capabilities. The ideal candidate will have strong statistical analysis skills, familiarity with LLM evaluation methodologies, and possess a collaborative and detail-oriented approach. B Capital is dedicated to providing top-tier compensation and comprehensive benefits to support their employees.

Qualifications

• Strong statistical analysis and experimental design skills.
• Familiarity with LLM evaluation methodologies.
• Detail-oriented and collaborative mindset.

Responsibilities

• Conduct critical comparative analysis to advance understanding of model capabilities.
• Build and refine evaluation systems that create feedback loops.
• Collaborate closely with teams to translate insights into model improvements.

Skills

Statistical analysis

Experimental design

LLM evaluation methodologies

Collaboration

Detail-oriented

Job description

Location

SF, NYC, London

Employment Type

Full time

Location Type

On-site

Department

Engineering

Our Mission

Reflection’s mission is to build open superintelligence and make it accessible to all.

We’re developing open weight models for individuals, agents, enterprises, and even nation states. Our team of AI researchers and company builders come from DeepMind, OpenAI, Google Brain, Meta, Character.AI, Anthropic and beyond.

About the Role

• Conduct critical comparative analysis to advance our understanding of model capabilities
• Build and refine evaluation systems and processes that create tight feedback loops between data, evals, and model behavior
• Develop generalizable evaluation frameworks that capture what matters for reasoning, alignment, and usefulness.
• Collaborate closely with pre-training, post-training, and applied teams to translate insights into model improvements.
• Push the boundaries of what’s measurable, from synthetic evals to human feedback and real-world interaction data.

About You

• Strong statistical analysis and experimental design skills to rigorously measure model improvements
• Familiarity with LLM evaluation methodologies: static benchmarks, human preference evals, and/or agentic tasks.
• High agency and thrive in a fast-paced startup environment; bias for impact over process.
• Excited to work in a new frontier lab, defining how we measure and accelerate progress toward more capable models.
• Collaborative, detail-oriented, and motivated by building the feedback loops that make models truly improve.

What We Offer:

We believe that to build superintelligence that is truly open, you need to start at the foundation. Joining Reflection means building from the ground up as part of a small talent-dense team. You will help define our future as a company, and help define the frontier of open foundational models.

We want you to do the most impactful work of your career with the confidence that you and the people you care about most are supported.

• Top-tier compensation: Salary and equity structured to recognize and retain the best talent globally.
• Health & wellness: Comprehensive medical, dental, vision, life, and disability insurance.
• Life & family: Fully paid parental leave for all new parents, including adoptive and surrogate journeys. Financial support for family planning.
• Benefits & balance: paid time off when you need it, relocation support, and more perks that optimize your time.
• Opportunities to connect with teammates: lunch and dinner are provided daily. We have regular off-sites and team celebrations.