Josh Symonds

• Marvin: Built and operate Marvin, a company-wide agent platform for code review, incident investigation, and internal workflows: 116 users across engineering, support, and operations in five months, about 50 weekly active.
• Orchestration: Engineered the Go/Kubernetes orchestration: ephemeral agent workers on a Nix-built image, per-user OAuth tool credentials, immutable versioned model routes with live provider preflight and pointer-flip rollback.
• LLM Gateway: Built the org-wide model gateway: SSO keys, stable model aliases, audit logs, zero-retention providers.
• Code Review: Shipped multi-stage agentic code review with independent verification and materiality filtering, posting inline GitLab comments: 2,100+ reviews, 87% positive on 300+ explicit ratings.
• Evaluation: Built a production-replay evaluation harness with frozen dev/holdout cases and a version-pinned LLM judge. Blind adjudication showed the incumbent verifier wrong on 37% of disputed verdicts; migrated review to open-weight models, cutting average cost per review 16× month over month while median wall time halved.
• Incident Investigation: Automated investigation of 2,170+ alert threads, gathering evidence through kubectl, BigQuery, and logs before posting assessments or escalating. Validated by continuous synthetic canaries and blackbox acceptance tests on a fresh cluster per run.
• Agent-Ready Monorepo: Built the layered documentation, agent skill framework, and progressive context disclosure that make a large fintech monorepo work under coding agents, shared by Marvin and engineers’ local Claude Code sessions.

• Go Services & Tooling: Built production Go services and developer tools used daily across a 30+ microservice platform: Kubernetes service proxy, end-to-end testing framework, unified CLI.
• Edge & Platform: Built OS-level provisioning for industrial IoT edge agents and led the migration from k3os to Talos Linux; architected multi-cluster EKS with Flux CD, environment promotion, and rollback.
• Org: Established the Core Services function; ran weekly LLM workshops that moved the engineering org onto AI tooling.

• Platform & Security: Built Kubernetes operators, multi-region failover, and custom Terraform providers; designed NIST CSF and ISO 27001 programs and passed audits by major financial institutions.

• Zero to Scale: Built greenfield AWS infrastructure that scaled M1 from zero to over a million customers; owned deployment pipelines and the security program; operated bare-metal Kubernetes and led the migration to EKS.

• Built and shipped an AI gaming companion spanning 14 games: open-source Go client with sandboxed WASM parsers; hosted MCP tools behind OAuth 2.1. Raw saves stay local; assistants receive structured game state and domain tools.
• Shipped a Go service pooling warm LuaJIT processes so agents can test build changes against Path of Building’s calculation engine. Ported its perturbation algorithms to Go; measured 40 ms p50 / about 300 ms p99 swap-and-recompute latency with an eight-process pool.

• Released Gambit, a contract-to-release coding-agent plugin with isolated workspaces, owned-file boundaries, failure-signature model routing, and evidence-backed gates. Built Tiltyard to replay repository-derived implementation tasks against model and harness combinations, scoring correctness, reliability, quality, discipline, and cost.

NixOS and Home Manager configuration for a nine-host fleet.