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Anthropic

Builds Claude AI models with a focus on safety

Anthropic Fellows Program Fellow - ML Systems & Reinforcement Learning

Winter 2027
$57.75 - $107.50/hr
Internship
Remote in USA+3 moreMore locations: Remote in Canada | Remote in UK | San Francisco, CA, USA
RemoteRemote fellows may be based in the UK, US, or Canada; shared workspace is available in San Francisco.
AI & Machine LearningAI Research
No H1B Sponsorship

About the job

Requirements
  • Fluency in Python programming.
  • Availability to work full-time on the Fellows Program.
  • Work authorization in the United States, United Kingdom, or Canada, and presence in that country during the program.
  • Strong technical background in computer science, mathematics, or physics.
  • Strong software engineering skills and experience building complex machine learning systems.
  • Ability to balance research exploration with engineering rigor and operational reliability.
  • Comfort working with large-scale distributed systems and high-performance computing; the ML Systems workstream cites experience in trading as an example.
  • Experience training, fine-tuning, or evaluating large language models.
  • Ability to analyze and debug model training processes.
  • For the Reinforcement Learning workstream, domain expertise relevant to creating reinforcement-learning environments is a potential fit criterion.
Responsibilities
  • Complete four months of full-time research, with a possible extension.
  • Use external infrastructure, such as open-source models and public APIs, to work on an empirical project aligned with Anthropic research priorities, with the goal of producing a public output such as a paper submission.
  • Participate in project selection and mentor matching.
  • For ML Systems & Performance projects, build a CPU simulator for accelerator workloads, add backends for different accelerators to an open-source project, build on-demand infrastructure for other infrastructure-heavy fellows projects, or build complex synthetic-data or environment pipelines.
  • For Reinforcement Learning projects, build model-based tools to understand AI training data and improve its quality; research generalization; create reinforcement-learning environments to improve Claude capabilities or support safety-related tasks; and conduct research and implement solutions in reinforcement-learning algorithms.
Desired Qualifications
  • Interest in transitioning into empirical AI research and in a potential full-time role at Anthropic.
  • Motivation to help ensure AI is safe and beneficial for society.
  • Ability to collaborate across research and engineering disciplines.
  • Ability to implement ideas quickly and communicate clearly.

About the company

Anthropic builds the Claude family of AI models and sells them to businesses, software developers, and consumers, with research on making AI safe and understandable at the center of its work. In 2024 it introduced the Model Context Protocol, an open standard for connecting AI assistants to outside apps and data that OpenAI and Google adopted the next year. People use the Claude app to write and analyze files, programmers hand coding tasks to Claude Code, and companies build Claude into their own products through its API. Anthropic earns money from subscriptions, business plans, and usage-based API fees. Siblings Dario and Daniela Amodei founded Anthropic in 2021 with other former OpenAI employees, and it is based in San Francisco.

Company Size

5,001-10,000

Company Stage

Debt Financing

Total Funding

$243.8B

Headquarters

San Francisco, California

Founded

2021

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Simplify's Take

What believers are saying

  • Sales are multiplying: Anthropic's yearly revenue pace topped $65 billion in July 2026, over sevenfold since December 2025.
  • IPO plans advanced: October 2026 reports describe investor meetings and a mid-November listing target; staff shares face lockups.
  • Lower office minimum: 627 of 646 Anthropic job posts in October 2026 require at least 25% office time.

What critics are saying

  • Job security rides on growth: Anthropic's IPO prospectus lists $518 billion in cloud and computing bills due in coming years.
  • Defense work stays off-limits: in September 2026, appeals judges voted 2-1 to let the Pentagon keep blacklisting Anthropic.
  • Growth is priced in: Anthropic's valuation reached $965 billion in May 2026, up from $380 billion in February.

What makes Anthropic unique

  • Investors don't control its board alone: Anthropic's independent Long-Term Benefit Trust elects a growing number of directors.
  • It isn't tied to one chipmaker: Claude runs on Nvidia GPUs plus custom AI chips designed by Google and Amazon.
  • It holds back its riskiest model: Claude Mythos 5.1, launched September 2026, goes only to vetted cyberdefenders and life scientists.

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Benefits

  • Flexible Work Hours
  • Paid Vacation
  • Parental Leave
  • Hybrid Work Options
  • Company Equity

Growth & Insights and Company News

6 month growth

-2%

1 year growth

3%

2 year growth

-2%
Tech in Asia
Oct 31st, 2026
Blackstone warns Anthropic may get junk rating after IPO, with $18B chip debt deal at stake

Blackstone has told investors that Anthropic, a US AI startup, may not get an investment-grade rating after a future IPO. It now expects a rating at the high end of junk, revising its earlier guidance. The US investment firm is backing an $18 billion debt deal tied to Anthropic's AI chips. On S&P and Fitch scales, BBB- or higher is investment grade, while BB+ or lower is high-yield, or junk. A junk rating usually means higher yields than investment-grade debt. It could also limit demand from pension and insurance investors that cannot hold below-investment-grade debt. Anthropic posted a net loss of over $80 billion in the first half of 2026, largely on paper.

Yahoo Finance
Oct 30th, 2026
Ex-SEC chair Gensler likens Broadcom's $63B Anthropic chip package to 2008 off-balance-sheet deals

Banks plan to sell up to about $21 billion of high-grade bonds as soon as early next year, part of a $63 billion package Broadcom assembled so Anthropic can buy its chips, Bloomberg reported. Former SEC Chair Gary Gensler said the deal, which is not yet in Anthropic's IPO filing, feels like "that 08 off-balance sheet craze." He also questioned guarantees written by Broadcom, NVIDIA, and AMD. A special purpose company buys the chips and leases them to Anthropic, whose payments repay the debt. Banks are lending about $42 billion, with Blackstone anchoring the rest, and Broadcom backs that senior debt against a fall in the chips' value. Broadcom shares trade at 20x forward earnings, well below the three-year average of 30x. Its annual report, due in December, will show how large its backstops have grown.

Yahoo Finance
Oct 30th, 2026
Jim Cramer warns it's too soon to buy beaten-down AI stocks as $700B capex worries grow

AI stocks are sliding, and CNBC's Jim Cramer says it's too soon to buy the dip. The Nasdaq CTA Artificial Intelligence Index, which tracks 58 stocks, is down 7.0% over the last month. Cramer wants to see better charts, reports from the hyperscalers, the election in the rearview mirror, and Anthropic's public listing before turning bullish on hard-hit AI data center stocks. Others urge a closer look at the numbers. Monte Malukas of Stockatomics says its AI Infrastructure Index is up around 70% over the past year, which suggests demand is not collapsing. Meta expects capital expenditure of $135 billion to $145 billion in 2026. Anthropic's IPO is expected in mid-to-late November at an estimated $1.5 trillion to $2 trillion valuation.

PR Newswire
Oct 29th, 2026
Bloomberg Law brings court dockets and litigation intelligence into Claude

Bloomberg Law has launched a connector that lets legal professionals use its federal and state court dockets data and litigation intelligence inside Claude, the AI tool. Users can search docket details and filing information, monitor matters with alerts and tracks, and surface litigation insights without running a separate search on the Bloomberg Law platform. The connector uses Model Context Protocol (MCP), a standard that links AI applications with external data and tools. "The value of an AI tool depends on the quality of the information it draws on," said Aaron Pierce, head of Bloomberg Law. He said the link helps lawyers review and compare filings, understand litigation trends, and spot opportunities in one workflow. The company says the move reflects its aim to meet legal professionals where they work, including in third-party tools.

Yahoo Finance
Oct 29th, 2026
Eisman warns AI giants have "no moats" as Morningstar sees $57B compute cost edge

Investor Steve Eisman, known from "The Big Short," says the AI boom depends on the health of OpenAI and Anthropic. He told CNBC that cheaper rival models could force the two labs to cut prices, threatening their heavy spending on computing power and exposing chipmakers and cloud providers. Morningstar disagrees. It estimates that bulk, multiyear deals could secure Nvidia B200 capacity at $2.25 per GPU-hour, against a $16.11 hyperscaler list price. For a gigawatt of computing power, that is roughly $9 billion a year instead of $66 billion, an illustrative $57 billion saving. Customers are shopping around, though. Anthropic's share of spending through Vercel's AI Gateway fell to 44% in September from 64% a month earlier. Anthropic's IPO filing showed $11.56 billion in second-quarter revenue and $974 million in operating profit.