Software Engineer, Tokens and Prompt Structures

The posting, as Anthropic wrote it

About Anthropic

Anthropic’s mission is to create reliable, interpretable, and steerable AI systems. We want AI to be safe and beneficial for our users and for society as a whole. Our team is a quickly growing group of committed researchers, engineers, policy experts, and business leaders working together to build beneficial AI systems.

About the Role

The Encodings Infra team maintains the libraries that engineers and researchers across Anthropic use to encode text and multimodal data into a form that Claude can consume. It also determines Claude’s prompt shape: how a user’s turn is represented to the model, how Claude calls tools and receives tool results, and so on.

As a Software Engineer on this team, you'll own the design and maintenance of these libraries—keeping their APIs intuitive, their performance sharp, and their abstractions solid enough that most of the org never has to think about encodings or prompt structures at all. You’ll have the satisfaction of knowing that your work enabled Claude to learn new ways of understanding the world.

This role is unusually broad: your work will touch systems across the codebase, from pretraining to finetuning to the API, and you'll collaborate closely with both researchers and engineers to make sure new encoding ideas can move quickly from experiment to production.

Responsibilities

Maintain and improve the encoding libraries used by engineers and researchers across Anthropic

Run experiments to determine the optimal way to feed structured data into Claude without confusing it

Design data structures and abstractions that shield most of the organization from the details of how encoded data works while enabling “power users”

Adapt the encoding libraries to support new research directions as they emerge, and make sure that we can ship these research ideas to production

Optimize encoding performance across the systems that depend on these libraries

You may be a good fit if you

Have 5+ years of software engineering experience, with meaningful time spent maintaining libraries, SDKs, or developer-facing APIs

Have familiarity with ML terminology and LLM architecture — you don't need to be an ML expert, but enough understanding to work effectively alongside researchers and understand the results of experiments

Have experience carrying out complex refactors in large codebases

Have strong communication skills and enjoy working closely with researchers and engineers to understand what they need

Are results-oriented, with a bias towards flexibility and impact

Pick up slack, even if it goes outside your job description

Care about the societal impacts of your work

Strong candidates may also have experience with

Tokenizers or other text/data encoding systems

Maintaining a widely-used library over a long period of time

Performance optimization

Python and/or Rust

Reinforcement learning or model training infrastructure

Representative projects

Working
[…]
n our team.

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How we're different

We believe that the highest-impact AI research will be big science. At Anthropic we work as a single cohesive team on just a few large-scale research efforts. And we value impact — advancing our long-term goals of steerable, trustworthy AI — rather than work on smaller and more specific puzzles. We view AI research as an empirical science, which has as much in common with physics and biology as with traditional efforts in computer science. We're an extremely collaborative group, and we host frequent research discussions to ensure that we are pursuing the highest-impact work at any given time. As such, we greatly value communication skills.

The easiest way to understand our research directions is to read our recent research. This research continues many of the directions our team worked on prior to Anthropic, including: GPT-3, Circuit-Based Interpretability, Multimodal Neurons, Scaling Laws, AI & Compute, Concrete Problems in AI Safety, and Learning from Human Preferences.

Come work with us!

Anthropic is a public benefit corporation headquartered in San Francisco. We offer competitive compensation and benefits, optional equity donation matching, generous vacation and parental leave, flexible working hours, and a lovely office space in which to collaborate with colleagues. Guidance on Candidates' AI Usage: Learn about our policy for using AI in our application process.