Rick Winfrey

Understanding code is hard.
I build systems for devs and AI to bridge the gap.

Formerly: Nuanced, GitHub MSc Software Engineering, Oxford

Writings

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Notable Work

Nuanced LSP

A multi-language LSP server multiplexer with a simple, unified API and a container-based architecture designed for both local and remote orchestration. Built to give AI agents the same precise, language-aware code intelligence that developers rely on every day.

Rust LSP SDK CLI Container orchestration

Nuanced Eval-Agent

An evaluation harness for analyzing multi-turn agent behavior in repeatable, isolated environments. It produces detailed breakdowns of tool usage and token consumption, and tracks the key metrics of task duration, cost, and efficiency. Eval-Agent also supports multi-step experiments, making it easy to measure how changes across iterations impact these metrics over time.

AI Observability Evaluation Experimentation Agents

GitHub Code Search

Core member of GitHub’s code search team, contributing across the full distributed system. I served as a lead author of the symbol-extraction library used during indexing and helped optimize the backfill pipeline, reducing end-to-end backfill duration from five days to 36 hours across more than 200M repositories.

Go Rust Tree-sitter Kafka Azure VMs

GitHub Copilot Chat

Contributed to the early development of GitHub’s AI assistant chat experience, including the core prompt-building library that manages dynamic prompt construction. Worked across Rust and Go backend services and integrated code intelligence capabilities such as GitHub code search and Tree-sitter into the chat workflow.

Go Rust Tree-sitter

GitHub Code Navigation

Helped build GitHub’s code navigation system from the ground up, spanning Go-based network services, a Ruby client embedded in the GitHub Rails monolith, and a backend architecture powered by MySQL Vitess and Azure Blob Storage. I co-authored the Kafka-based ingest and indexing pipeline, separating CPU-bound and I/O-bound workloads across dedicated queues and services to scale navigation across millions of repositories.

Go Rust Tree-sitter MySQL Vitess Blob Storage Kafka

Tree-sitter

Contributed patches to the Tree-sitter runtime and library, and played an early key role in building out its language grammar ecosystem. I worked on grammars for JavaScript, Python, and Ruby, and wrote the first version of the Haskell grammar.

C Rust Parsing Language Grammars

GitHub Semantic

Helped author an experimental program analysis library written in Haskell to parse, diff, and analyze the source code for multiple programming languages. GitHub code navigation emerged from this research prototype.

Haskell Program Analysis

ActionLogic

A Ruby gem for cleanly structuring business logic: define composable units of work, bundle them into use cases or coordinators, and compose reusable workflows with shared context. Designed to keep code readable, testable, and maintainable, even as business logic grows in complexity.

Ruby Business logic abstraction

Recently

08-2025 — 12-2025

Founding Staff Engineer

  • Built Nuanced LSP, a multi-language LSP control plane with a container-based architecture and unified API designed to give AI agents the same code intelligence developers rely on.
  • Developed Eval-Agent, a multi-turn evaluation harness that measures agent performance, tool usage, token efficiency, and cost across controlled experimental runs.
  • Created a TypeScript SDK and CLI tooling that make Nuanced LSP seamless to adopt in both human and agent development workflows.
  • Directly engaged with customers to understand their needs, shape product direction, and rapidly deliver improvements that added immediate value to their development and agent workflows.
11-2015 — 07-2025

Senior Software Engineer

  • Collaborated with product, design, and infrastructure teams to deliver reliable, large-scale code navigation and search across GitHub surfaces serving millions of daily requests.
  • Core contributor to GitHub's code intelligence ecosystem, working across distributed systems, language tooling, and developer experience for millions of users.
  • Helped build Aleph, GitHub's code navigation system, including Go-based network services, a Ruby client in the Rails monolith, a Vitess/MySQL and Azure Blob Storage backend, and a Kafka-based ingest pipeline separating CPU and I/O bound workloads.
  • Core member of the Blackbird code search team, contributing to the system's distributed architecture, co-authoring the symbol-extraction library, and optimizing the backfill pipeline — reducing end-to-end backfill duration from five days to 36 hours across 200M+ repositories.
  • Early contributor to GitHub Copilot Chat, authored the core dynamic prompt-construction library, and helped architect and integrating code intelligence signals into the chat experience.
  • Contributed to the Tree-sitter runtime and grammar ecosystem, improving grammars for JavaScript, Python, Ruby, and creating the first Haskell grammar.
  • Worked on Semantic, an experimental programming-language analysis framework for static analysis and code understanding.

Personal

When I'm not building software, I'm making sawdust in the workshop, chasing waves, or cooking Neapolitan pizza.