Josh Symonds

Hands-on staff engineer: agent platforms, evals and verification, and AI infrastructure.

Santa Barbara, CA [email protected] +1-773-480-4810 github.com/joshsymonds Download PDF

Built a company-wide agent platform and replay evals that moved its review to open-weight models, plus a decider model that replaced LLM-as-judge. Building by directing coding agents since 2025; fifteen years in infrastructure and security.

Experience

Attain

Remote
Director of SRE, Consumer Product Mar 2026 – Present
  • Marvin: Created Marvin, our company-wide agent platform in Slack; 116 people across engineering, support, and operations use it for code review, incident investigation, and internal workflows, about 50 of them weekly.
  • Orchestration & Gateway: Designed Go/Kubernetes orchestration for ephemeral agent workers on a Nix-built image, with per-user OAuth credentials, Cedar tool policies, and versioned model routes with one-step rollback. Launched the company’s LLM gateway: SSO-issued keys, request logs, per-person spend, and zero-retention providers only.
  • Code Review: Shipped multi-stage AI code review with a verifier pass that checks findings and drops nitpicks: 2,100+ reviews, 87% positive (300+ ratings).
  • Evaluation: Built an evaluation harness that replays production reviews against candidate models, with frozen dev/holdout cases and a version-pinned LLM judge. Blind review found the original verifier wrong on 37% of disputed calls. Moved review to open-weight models; with pipeline changes, cost per review fell 16× in a month and median review time halved.
  • Incidents: Automated investigation of 2,170+ alert threads, gathering evidence from kubectl, BigQuery, and logs before escalating or opening a merge request with the fix, mergeable as written 95% of the time.
  • Agent-Ready Monorepo: Made a large monorepo agent-ready with docs, agent skills, and on-demand context, shared by Marvin and engineers’ own Claude Code sessions.
  • Hiring: Designed Attain’s AI-assisted SRE take-home interview, where candidates work on a real cloud machine with a coding agent and are graded mainly on how they work with it.

Independent Engineering, Built with Coding Agents

Savecraft

Go, TypeScript, Rust, WebAssembly, MCP · 2026
  • Shipped an AI gaming companion for 14 games, in OpenAI’s connector directory: sandboxed WASM save parsers on the player’s device, so raw saves never leave it, and MCP tools and the chat loop on Cloudflare Workers behind OAuth 2.1.
  • Built its eval system before choosing a model: 295 scenarios × 3 runs from production logs. A 13-model bake-off ranked an open-weight model first, ahead of frontier models costing 14× more. Replaced LLM-as-judge with a decider model (Jev) validated on held-out pairs, which picked the stronger model in 95% of pairs vs 88% for the old judge (p = 1.9e-17).
  • Built a Go service pooling warm LuaJIT processes so agents can test builds against Path of Building’s calculation engine (40 ms median).

Gambit & Tiltyard

Claude Code, Go
  • Released Gambit, a Claude Code plugin that takes tasks from spec to release with test-evidence gates. Tiltyard replays real repository tasks to score models and agent harnesses.

LiveWorld (consulting)

AWS, EKS, Terraform, Flux · 2013 – Present
  • Run its AWS/EKS platform and GPU inference for its ML product (Karpenter, KEDA); wrote its SOC 2/GDPR controls.

Open Source

Original author of Dynamoid, the Ruby ORM for DynamoDB (13M+ downloads). nix-config: NixOS and Home Manager for a nine-host fleet (837 stars).

Previous Roles

CrossnoKaye

Santa Barbara, CA
Principal Infrastructure Engineer / Senior Manager, Core Services Jan 2021 – Feb 2026
  • Platform: Built the control plane and deploy tool (approval-gated, about 5,800 deploys in 2025), the end-to-end test framework, and the CLIs; ran 9 AWS accounts and 10 EKS clusters.
  • Edge: Built the industrial IoT edge OS with zero-touch provisioning and over-the-air updates, and led the migration from k3os to Talos Linux as the fleet grew to 123 production deployments.
  • Security & AI: Built a RAG Slack assistant over company documents, in production since May 2024 (AWS Bedrock, Claude). Led SOC 2 Type 1 and presented an IIAR paper on industrial cybersecurity. Set the LLM usage policy and ran weekly “Cooking with Claude Code” workshops.

Capital Markets Gateway

Chicago, IL
DevOps Engineer & CISO Oct 2019 – Dec 2020
  • Wrote Kubernetes operators and set up multi-region failover on AKS, wrote custom Terraform providers, and ran the NIST CSF and ISO 27001 programs that passed bank audits.

M1 Finance

Chicago, IL
Chief Information Security Officer Aug 2015 – Oct 2019
  • Employee #8. Built M1’s infrastructure from launch to nearly $1B in assets (Chef, then self-run Kubernetes, then EKS) and ran security through SOC 2 and SEC, FINRA, and bank audits.

Education

University of Chicago

Chicago, IL
BA in East Asian Languages and Civilizations