Employer listing
Software Engineer, Tokens and Prompt Structures
Anthropic
San Francisco, Ca · hybrid · full time
$320,000 - $405,000
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.
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
Qualifications
Minimum Qualifications
- Bachelor’s degree or an equivalent combination of education, training, and/or experience
- 5+ years of software engineering experience, with meaningful time spent maintaining libraries, SDKs, or developer-facing APIs
- Familiarity with ML terminology and LLM architecture
- Experience carrying out complex refactors in large codebases
- Strong communication skills and collaborative mindset
- Results-oriented with a bias towards flexibility and impact
Preferred Qualifications
- Experience with tokenizers or other text/data encoding systems
- Experience maintaining a widely-used library over a long period of time
- Experience with performance optimization
- Experience with Python and/or Rust
- Experience with reinforcement learning or model training infrastructure
Benefits
Anthropic offers competitive compensation and benefits, optional equity donation matching, generous vacation and parental leave, flexible working hours, and modern office spaces.