---
title: 'Member of Technical Staff - Pre-Training  Data at Reflection'
canonical: 'https://feeny.ai/job/member-of-technical-staff-pre-training-data-reflection-san-francisco-6gce6bbey29t'
type: 'job'
last_seen: '2026-11-05'
---

# Member of Technical Staff - Pre-Training  Data at Reflection

- **Company:** Reflection
- **Location:** San Francisco, CA
- **Employment:** full-time
- **Work type:** onsite
- **Posted:** 2026-10-22
- **Last confirmed live:** 2026-11-05
- **Apply:** https://jobs.ashbyhq.com/reflectionai/2b0b0fbf-0e82-4212-be2e-36e4ca37756c

## Job description

## Our Mission

Reflection is a research lab making intelligence open and accessible for everyone to use, customize, and build on. We build open models that let anyone control their intelligence and help shape the future of AI. Our mission: make intelligence open and accessible to all. What You’ll Do:

- Design and implement techniques for sourcing, curating, and filtering large-scale web, text, and code data, with opportunities to extend into other modalities as our models evolve.
- Develop data quality metrics and analyses that measure coverage, diversity, and representativeness across sources.
- Join the pre-training research team to design and run data experiments, working with infrastructure teams to scale the supporting data systems efficiently and reproducibly
- Investigate and mitigate data risks, including privacy, safety, and licensing concerns, to support responsible and ethical data use.
- Evaluate dataset changes through ablations and scaling experiments, tracing their downstream effects on model learning and behavior.
- Publish and present research, and share code, datasets, and insights that move the open AI community forward.

What We're Looking For:

- Proficiency in Python and familiarity with at least one deep learning framework (e.g., PyTorch or JAX), with experience debugging distributed workloads and writing code that scales.
- Bachelor’s degree or equivalent experience in Computer Science, Machine Learning, Physics, Mathematics, or a related discipline with strong theoretical and empirical grounding.
- Clear written communication and the ability to explain complex technical ideas.

Preferred qualifications (we encourage you to apply even if you don’t meet all of these, but at least some):

- A strong grasp of probability, statistics, and ML fundamentals, and the ability to tell real effects from noise and bugs in experimental data.
- Experience with curation, preprocessing, and analysis of large-scale text or code datasets; exposure to multimodal data is a plus.
- Background in data engineering, dataset construction, or large-scale web data processing for machine learning.
- Experience evaluating or improving training data quality, and knowledge of data ethics, safety, and licensing frameworks relevant to AI datasets.
- Contributions to open datasets, research publications, or data tooling.
- PhD in Computer Science, Machine Learning, Physics, Mathematics, or a related discipline; or equivalent industry research experience.

What We Offer: We believe that to make intelligence open and accessible to all, you need to start at the foundation. Joining Reflection means building from the ground up as part of a talent-dense team. You will help define our future as a company, and help define the future 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 our talent globally.
- Stock options: Everyone who joins and contributes to Reflection's success gets to share in the upside through stock options.
- Health & wellness: Comprehensive medical, dental, vision, and life, with an annual wellness allowance.
- Meals: Lunch and dinner are provided in the office daily.
- Life & family: 22 weeks paid parental leave for all new birthing and non-birthing parents, including adoptive and surrogate journeys.
- Vacation days: Unlimited paid time off in the U.S. and 30 days in the U.K.
- Sponsorship support: We sponsor visas to help exceptional talent join our team and support long-term immigration pathways where applicable.
- Team building: We have regular off-sites, happy hours, and team celebrations.

Export Control Notice: This position may require access to technology or source code subject to the U.S. Export Administration Regulations. Any offer of employment for this role may be conditioned on the Company's ability to provide the candidate with access to such technology or source code in compliance with applicable U.S. export control laws, which may require the Company to seek government authorization.

## Equal Employment Opportunity Statement

Reflection AI is an equal opportunity employer. We do not discriminate on the basis of race, color, religion, sex (including pregnancy), sexual orientation, gender identity or expression, national origin, ancestry, age, marital status, disability, genetic information, veteran or military status, or any other characteristic protected by applicable law. We encourage applicants from all backgrounds to apply.

We provide reasonable accommodations throughout the hiring process for applicants with disabilities, pregnancy-related limitations, or religious needs. If you need an accommodation, contact us at accommodations@reflection.ai.

We will consider for employment qualified applicants with arrest and conviction records in accordance with applicable law, including the San Francisco Fair Chance Ordinance and the California Fair Chance Act.

Candidate and Employee Privacy Notice: We collect and process personal data about applicants for the purposes described in our [Candidate and Employee Privacy Notice](https://cdn.sanity.io/files/irpbdun9/production/ee08c38bf22bd45a3f3a81f6a7abddb9210726b7.pdf)

## About Reflection

## Company Overview
- **One-liner**: Reflection is an AI lab building frontier open-weight models and superhuman coding agents, founded by former researchers from DeepMind, OpenAI, and Anthropic.
- **Entity Type**: Private (funding stage: Series B)
- **Headquarters**: New York, New York, United States
- **Founded**: 2024 (seed round in September 2024)
- **Founders**: Misha Laskin (Co-Founder, CEO), Ioannis Alexandros Antonoglou (Co-Founder, President & CTO)

## Core Business
- **Primary industry/industries**: Artificial Intelligence (AI research and development), Software Development
- **Target customers**: Enterprises, governments, sovereign entities, and developers seeking open, high-performance AI models and autonomous coding agents (B2B, B2G).
- **Mission or purpose statement**: "Make intelligence open and accessible to all" – building frontier open-weight models with transparent research and collaborative development.

## Products & Services
- **Reflection Open-Weight Models**: Frontier large language models (LLMs) designed for enterprise and sovereign use, offering ownership and control.
- **As I/O (Announced 2025)**: A production-ready platform "powered by Reflection" that gives organizations a complete, integrated system for deploying AI agents and workloads.
- **Autonomous Coding Agents**: Superhuman coding agents that automate knowledge work performed on a computer (core research focus).

## Market Standing
- **Valuation/Market Cap**: Not publicly disclosed
- **Key Metric**: **Total Funding** – $2.13 billion across three rounds:
  - Seed (Sep 2024): $25M (2 investors)
  - Series A (Mar 2025): $105M (2 investors)
  - Series B (Sep 2025): $2.0B (12 investors)
- **Notable Investors/Partners**: Investor names not publicly listed in available sources; board includes Max Gazor and Raviraj Jain. Partners not disclosed.
- **Growth Signals**:
  - Headcount grew **411.4% YoY** to 126 employees (as of mid-2026).
  - Active job postings: **80** (up 1,233% YoY).
  - LinkedIn followers: 21,763 (up 508% YoY).
  - Offices in New York (HQ), San Francisco, London, Washington D.C., and Toronto.
  - Talent sourced from Google DeepMind (13), Meta (14), OpenAI (3), and other top labs.

## Competitive Advantages
- **Open-weight philosophy**: Differentiates from closed labs like OpenAI and Anthropic by giving enterprises and governments full ownership and control of frontier AI.
- **World-class team**: Founders and researchers previously built ChatGPT, Gemini, AlphaGo, and AlphaZero – proven track record in both LLMs and agent systems.
- **Massive capital**: $2.1B in funding allows aggressive compute investment and talent acquisition.
- **Full-stack AI capability**: From training frontier LLMs to deploying production-grade agent platforms (As I/O).

## Strategic Focus
- **Current priorities**: Scaling open-weight models to frontier performance; building autonomous coding agents that automate knowledge work; expanding enterprise and sovereign sales (e.g., "Regional Commercial Lead, Sovereign – Europe" job posting).
- **Direction**: Making open intelligence the default for enterprise and government AI adoption, with a strong emphasis on transparency and sovereign control.

## Why Work Here
- **Culture highlights**: Mission-driven ("Mission above ego"), high trust, extreme ownership, and collaboration. Values include "Trust through truth" and "One team".
- **Remote/hybrid/office policy**: In-office daily with lunch and dinner provided. Offices in New York, San Francisco, London, Washington D.C., and Toronto. Relocation support available.
- **Notable perks**:
  - **22 weeks paid parental leave** for all new parents (including adoptive and surrogate).
  - Unlimited paid time off (U.S.) / 30 days (U.K.).
  - Stock options for all employees.
  - Comprehensive medical, dental, vision, life insurance, and annual wellness allowance.
  - Visa sponsorship for exceptional talent.
- **Engineering culture**: Build from the ground up alongside top researchers and engineers; strong emphasis on research and engineering roles (62 technical employees out of 126).

## Sources
1. [reflection.ai](https://reflection.ai/)
2. [Reflection Careers](https://reflection.ai/careers)
3. [LinkedIn - Reflection](https://www.linkedin.com/company/reflectionai)
4. [The Org - ReflectionAI](https://theorg.com/org/reflectionai)
5. [Ashby Jobs - Reflection](https://jobs.ashbyhq.com/reflectionai)

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