TechStone Creative Company

AI features for the product you already run

I'm Ken, a full-stack engineer with 17 years of experience. I add Claude and OpenAI features to existing apps, connect internal tools to AI agents, and build the web and cloud work around them.

See the workAlso on:Fiverr Wishket

What I build

AI features, web apps and the cloud work around them

AI features for existing apps

Chatbots that answer from your documents, Claude or OpenAI features in Node.js apps, MCP servers for AI agents.

Web apps and sites

Next.js and Node.js apps, admin pages and APIs, Shopify stores and themes.

Cloud and infrastructure

AWS, Kubernetes, CI/CD and cloud cost reviews for small teams.

Selected work

Demos and company projects

Three demos I built, then four projects I did at companies. Companies are named by industry only.

Demos

The chatbot in mock mode answering a billing question from the sample help docs

Chatbot that answers from your documentsA RAG chatbot that answers only from your help docs, shows its sources and embeds on any site with one script tag.Next.jsTypeScriptClaudeRAG

Ticket classification in mock mode, a support message in and a structured JSON object out

Claude features in an existing Express APIThree Claude-powered endpoints added to an example shop API, with schema-checked JSON output and streaming.Node.jsTypeScriptExpressClaude

An update_stock call rejected because it would make stock negative, with the error the agent reads

MCP server for your shop back officeAn MCP server that lets Claude and other AI agents search, check and update shop data through validated tools.Node.jsTypeScriptMCPClaude

Company projects

Release flow before and after the move, from agency handoffs to pull requests and GitHub Actions

Moving an outsourced company website in houseTook over a website run by an outside agency and gave it a Git-based release process.AWSGitGitHub ActionsCDN

Architecture of the deployment API, AKS clusters in three regions and the supporting tools

Multi-region platform and one-click deploys for a healthcare SaaSRedesigned the infrastructure of a healthcare SaaS for the US market and cut cloud cost by more than 60%.KubernetesAzure AKSHelmArgoCD

Operations staff use a Retool dashboard backed by a Lambda REST API and MySQL

Automating retail operations workMoved manual ordering, order lookup and product management onto an API and an admin dashboard.AWS LambdaServerless FrameworkNode.jsMySQL

Member web and app plus an internal back office on one REST API, and the move from EC2 to EKS

Back office and a move to KubernetesBuilt a Node.js back office with Salesforce and SAP integrations and moved the infrastructure from EC2 to EKS.Node.jsExpressVue.jsReact Native

All work

How I work

What working together looks like

Scope in writing

Before work starts, we agree on scope, timeline and deliverables in writing.

Short written updates

You get brief progress notes as the work moves, so you can see where things stand without a meeting.

Tests and a README

Code arrives with tests and a README, so another developer can pick it up later.

Async, on Korea time

I work asynchronously on Korea Standard Time (KST) and keep decisions in writing.

About

Ken, full-stack engineer

As CIO of a healthcare SaaS for the US market, I ran multi-region infrastructure for more than 500 services under HIPAA and GDPR requirements.

TechStone Creative Company is the name I take on freelance work under. I use AI coding agents, Claude Code and Codex, every day.

Contact

Tell me what you want to build

Send a short note about what you want to build. I reply in writing with scope and a timeline.

techstonecc@gmail.com Fiverr Wishket