JMSN Consulting
Agentic software engineer
I build production systems with LLM coding agents — the harnesses, evaluation loops, and review guardrails that make agent-written code safe to merge. Backed by a full-stack engineering career across fintech, gaming, and large-scale e-commerce — most recently as a Principal Engineer at Amazon.
Services
Contract and fractional engagements, remote. Short scopes welcome.
Getting LLM coding agents productive on a real codebase: agent harnesses, evaluation loops, automated code review, and the guardrails that let a team trust what the agent produces. I use this workflow on my own client work, not just in theory.
Backend services, APIs, and the frontend that sits on them — Go, Java, Python, React, on AWS and Kubernetes. Most of my recent work has been landing production features inside unfamiliar codebases on short timelines.
Design review, threat modeling, and security assessment. I served as an internal security reviewer at Amazon across e-commerce and games, vetting designs and implementations before they shipped.
Experience
Fifteen years at Amazon across e-commerce, games, and satellite connectivity, preceded by systems work in telecom and aviation.
JMSN Consulting
2026 — Present
Independent practice focused on agentic software development. Most recent engagement: Remitly, on the Emerging Markets receivers team — architected the integration of a non-custodial embedded wallet into the receiver payment flow, including stablecoin transfer and cross-chain conversion, shipped to production behind a feature gate. Also designed the full-stack architecture for customer-initiated private key export, the capability that makes the product genuinely non-custodial.
Go · Java · React · Kubernetes · AWS · Claude Code · Codex
Amazon
2022 — 2026
Led full-stack architecture for the Kuiper e-commerce platform — business accounting, invoicing, and supply chain systems across 16 countries. Built an automated testing solution driven by generative AI that generated and maintained thousands of test cases across a microservices fleet. Internal security reviewer.
Java · Python · JavaScript · AWS · Microservices
Amazon Games
2016 — 2022
Backend microservices for AAA titles including Lost Ark — identity authorization and account linking handling thousands of authentications per second. Designed a machine learning pipeline for games advertising processing hundreds of gigabytes daily.
Java · Python · CloudWatch · AWS · NoSQL
Amazon Appstore
2011 — 2016
Re-architected the Android application submission process, migrating a monolith to microservices behind a full REST API. Built the CI/CD and automated testing that shortened release cycles.
Java · JavaScript · REST · CI/CD
Integrated Telecom · Cirries · Southwest Airlines · Verizon · IpVerse · Nortel
Prior to 2011
Call-processing and charging systems for IP IMS/GPRS networks on DIAMETER/SIP with SS7 interop; converged telecom architecture; multi-threaded, fault-tolerant C++ and Java frameworks; billing and provisioning data warehouse integration.
C++ · Java · DIAMETER/SIP · SS7 · Oracle
Holder of US Patent No. 9,823,909 · B.S. Computer Science, cum laude, University of Texas at Dallas
Open work
Things I build outside client work. Running code with source you can read — more samples from the consulting practice will land here as engagements allow.
A local credential broker: one always-running daemon that vends short-lived, capability-scoped secrets to your tools — so keys stop sprawling across dotfiles, env files, and shell history. Written in Rust, Apache-2.0, 302 tests green.
A study of what the GDELT Project actually publishes — four of its advertised datasets are dead or frozen, and none of them error — plus the tools built on the parts that still run, including a live world news map rebuilt every 15 minutes while the generator is awake.
Contact
Available now for contract and fractional engagements, remote across US time zones. Tell me what you're building and where it's stuck — I'll tell you honestly whether I'm the right person for it.