Joshua Shepelsky mountain biking at a trail summit

About Me

Senior full-stack engineer who ships AI-powered features and serverless AWS systems in production, including real-time event pipelines processing tens of thousands of events per day. 10+ years across SaaS, media, eCommerce, and enterprise platforms; expert in PHP, TypeScript, React, Angular, and Next.js. Owns complex systems from architecture through launch.

Known for shipping high-impact features at speed and modernizing legacy platforms. Raises engineering quality on every team he joins. Works hands-on with Claude, OpenAI, and AWS Bedrock, and ships his own products too: an AI-powered iPhone app taken solo from first commit through Apple's App Store review, plus an open-source Claude Code plugin.

AI product engineerShipped AWS Bedrock and OpenAI API features in production, plus an iPhone app that parses grocery receipts with Claude vision and structured outputs. Uses Claude Code daily to fit more into a sprint without dropping quality.

Integration specialistSalesforce, HubSpot, Stripe, Recurly, Vertex Tax, Google Maps, Heap and more. All shipped in production.

Makes teams fasterIntroduced AI-assisted workflows, prompts, and review processes that measurably improved code quality, review depth, and team velocity, then published that tooling as an open-source Claude Code plugin.

SEO & AEOCore Web Vitals, schema markup, Open Graph, Ahrefs, Varnish, Cloudflare, plus Answer Engine Optimization that gets content cited in ChatGPT, Perplexity, and Google AI Overviews.

Contact Details

Joshua Shepelsky
Charlotte, NC US
jshepelsk@gmail.com
github.com/jshepelsky

Engineering Profile

10+ years of production-grade work across SaaS, media and enterprise.

A cross-section of what I build: integrations, AI features, APIs, performance systems, payment flows and team delivery, all shipped in production.

AI-Powered Features

Shipped TossCost, a native iOS app (SwiftUI + SwiftData) that parses grocery-receipt photos with Claude vision and structured outputs through a Cloudflare Worker proxy, with Durable Object spend caps, kill-switch cost controls, and private iCloud sync. Built solo, end to end, and approved through Apple's App Store review.
Built a Next.js application powered by AWS Bedrock that generates structured collision repair estimates with cost logging and a multi-step reviewer workflow.
Integrated OpenAI API into a content validation pipeline for automated detection and secure storage of prohibited content at scale.
Published an open-source Claude Code plugin: 13 stack-detecting review and testing agents, 21 commands, lifecycle hooks, and multi-agent workflows that tailor themselves to any codebase.

Cloud & Developer Operations

Provisioned a full serverless AWS stack via CDK: Lambda (Node.js), API Gateway with API-key enforcement and monthly quota management, DynamoDB with point-in-time recovery, S3 with presigned URLs, Secrets Manager, WAFv2 rate limiting, and CloudWatch logging.
Wrote Makefile-driven developer workflows with 50+ targets: Docker orchestration, database migrations and seeding, dependency installs, SCSS/JS builds, and full AWS Elastic Beanstalk deployment with per-environment variable management.
Built Docker Compose multi-service environments for PHP/Node/MySQL stacks with health checks and asset pipelines, so a new developer can boot the whole platform with one command.
Managed AWS RDS for production database hosting; used AWS SES for transactional email and S3 for file uploads and contact imports across multiple production platforms.
Run production workloads on Cloudflare Workers: Durable Objects for spend caps and coordination, Workers Analytics Engine telemetry, custom domains, and a hardened LLM proxy with app-token auth.

Enterprise Integrations

Salesforce bi-directional sync: contact sync settings, flow creation/deletion, outbound messaging, webhook handling, and installation management.
HubSpot custom workflow actions, event tracking, Automation Action background processing, affiliate CRM sync, and review collection with eligibility logic.
Vertex Tax API for multi-state sales tax (AZ, LA, MD, WI); ActiveCampaign, AWeber, Heap, RevenueHero, and VWO.

APIs, Webhooks & Data

Architected an entire webhook system from scratch that processes tens of thousands of events per day: MongoDB-backed event storage, real-time delivery reports, CRM sync, bad number removal notifications, and subscriber tracking.
Authored full API and webhook documentation: endpoint references, payload schemas, authentication flows, signature verification, and developer integration guides.
Designed and shipped JWT-secured REST APIs with full CRUD and role-based access; implemented OAuth and webhook signature verification across integrations.
Integrated Google Maps JavaScript API with Google Places and Geocoding APIs for address autocomplete, zip-to-coordinate resolution, location enrichment, and interactive map rendering with custom markers.

Engineering Leadership

Introduced AI-assisted workflows across the engineering team: rules, prompts, and review processes that measurably improved code quality, code review depth, and team velocity.
Led a team of four engineers and a QA through 30+ two-week sprint cycles: Agile ceremonies, sprint planning, and consistent on-time cross-functional delivery.
Overhauled a large legacy codebase for security: eliminated SQL injection vulnerabilities and worked through the remaining critical flaws one class at a time.
Mentored junior developers through code reviews, pair programming, and hands-on coaching; translated product requirements into clear technical tickets.

Payments & Business Systems

Stripe integration end to end: billing webhooks, payment link generation, checkout session fulfillment, subscription management, and invoice handling.
Recurly subscription management; self-serve plan cancellation; subscription configuration UI with plan history display and pricing logic fixes.
Built admin tooling: auditor interfaces, message log download, customer management panels, registration status dashboards, and toll-free migration tracking.
Implemented anti-spam and abuse protections across subscriber-facing widgets and web forms, securing intake flows and subscriber data quality.

SEO, AEO & Performance

Drove Answer Engine Optimization (AEO) strategy: structured content, schema, and site architecture so answers get cited in ChatGPT, Perplexity, and Google AI Overviews. Tracked how the brand surfaced in AI answers and kept iterating until it showed up.
Used Ahrefs for keyword research, content gap analysis, backlink audits, and tracking organic search performance.
Rebuilt large-scale marketing sites: deferred script loading, lazy loading, cache busting, asset versioning, Core Web Vitals optimization, and Schema.org structured data across 50+ pages.
Optimized a Varnish caching layer to raise cache hit rate above 90%, cutting origin load on a property serving millions of monthly visitors; implemented Cloudflare with bot protection, DDoS mitigation, and server-side security rules.
Cut server resource requirements by over 50% after a hosting migration through application-level optimizations, which materially lowered ongoing infrastructure costs.

AI Workflow

I use AI like a senior engineering tool, not a shortcut.

Ships AI productsAn iPhone app that reads receipts with Claude vision and structured outputs, a Next.js collision estimator on AWS Bedrock, and OpenAI-powered content moderation, all with per-call cost logging and guardrails.

Builds the primitivesPublished an open-source Claude Code plugin: 13 subagents, 21 commands, lifecycle hooks, and multi-agent workflows. Writes agents, skills, and structured-output schemas as everyday engineering tools.

Daily driverUses Claude Code every day: scoped prompts, batched work, verified output. Multi-day tasks become focused sprint items without lowering the quality bar.

Selected Projects

Production work across AI, SaaS, integrations and infrastructure.

Every card below is something real that shipped: platforms built from scratch, integrations delivered, systems hardened, and AI features running in production.

iOS App · AI

Designed, built, and shipped a native iPhone app solo: TossCost scans grocery receipts with Claude vision and structured outputs via a Cloudflare Worker proxy, tracks what food gets tossed, and shows exactly how much money is wasted. SwiftUI and SwiftData with private iCloud sync, Durable Object spend caps, and kill-switch cost controls. Every layer, from the Swift codebase to the LLM backend, passed Apple's App Store review.

SwiftSwiftUISwiftDataCloudKitClaude APICloudflare Workers

tosscost.com

AI / Machine Learning

Built an AI application powered by AWS Bedrock that generates structured, line-item collision repair estimates. Includes a multi-step reviewer workflow, API-key enforcement, usage-cost logging per inference call, and full Swagger/OpenAPI documentation.

Next.jsTypeScriptTailwindAWS BedrockOpenAPI

SaaS Platform

Architected a multi-tenant certification platform end to end: verified signup and billing, photo certification with live camera capture and geolocation, appointment scheduling, role-based access control, admin dashboards, a shop locator with phone-click tracking, and SEO schema markup.

PHPMySQLDockerAWS Elastic Beanstalk

Open Source · AI Tooling

Published essentials, an open-source Claude Code plugin: 13 stack-detecting code-review and testing agents, 21 slash commands, lifecycle hooks, and multi-agent workflows, plus a first-run profiler that tailors every agent to the host codebase. Works across PHP, JavaScript/TypeScript, Python, Go, and Ruby.

Claude CodeAI AgentsAgent SkillsHooksMulti-Agent Workflows

github.com/jshepelsky

Mobile Marketplace

Building a recreation-logistics marketplace end to end as a solo developer: one Expo codebase shipping to iOS, Android, and web; a Hono API on Cloudflare Workers; Neon Postgres with real transactions for offer-acceptance races; Stripe Connect onboarding, KYC, and payouts; a matching engine with a live dispatch board; and per-trip Durable Objects streaming location over WebSockets.

React NativeExpoCloudflare WorkersHonoNeon PostgresStripe Connect

Enterprise Integration

Built a complete Salesforce bi-directional CRM sync from scratch: contact sync settings, flow lifecycle creation and deletion, outbound message creation, webhook handling, and full installation management for enterprise customers.

PHPSalesforce APIWebhooksMySQL

API & Infrastructure

Designed and built an enterprise real-time webhook system from scratch, processing tens of thousands of events per day across delivery reports, subscriber events, and customer integration events. Authored complete developer documentation: endpoint references, payload schemas, auth flows, and signature verification.

PHPMongoDBREST APIsJWT

DevOps & Automation

Designed a 50+ target Makefile for a multi-service production platform: one command starts the full Docker stack, runs migrations, and seeds the database, and a single command deploys to AWS Elastic Beanstalk with per-environment variable management. Also wrote a one-command shell script that clones all repos, installs dependencies, and boots the entire platform from scratch.

MakefileDocker ComposeAWS Elastic BeanstalkAWS CLI

Location & Maps

Engineered a location-based shop finder using Google Maps JavaScript API, Google Places API for business enrichment via name and address lookup, and Geocoding API for zip-to-coordinate resolution. Includes interactive map with custom markers, info windows, phone-click tracking, and a rate-limited search API backed by MySQL.

PHPGoogle Maps APIGoogle Places APIGeocoding APIMySQL

Full-Stack Platform

Built a full directory and billing platform end to end: full-text search, tiered featured listings, user notifications, Stripe billing with webhook fulfillment, a JWT-secured REST API for ad sponsorship management, and admin approval workflows.

PHPPostgreSQLStripeCodeIgniterSendGrid

Security & Performance

Implemented Cloudflare with bot protection, DDoS mitigation, and server-side security rules on a media property serving millions of monthly visitors. Optimized a Varnish caching layer to raise cache hit rate above 90% and reduce origin load. Cut server resource consumption by over 50% post-migration, materially lowering ongoing infrastructure costs.

CloudflareVarnishNginxServer Hardening

Fintech / Trading

Built a trading platform with full brokerage API integration: order placement and management, watchlist functionality, a custom database migration runner, and developer-facing API documentation across all account and position endpoints.

PHPTradier APIMySQLREST APIs

Product Feature

Built a multi-step review and feedback collection system with eligibility logic, third-party embed retrieval, CRM data sync, and persistent storage. It directly improved organic social proof and sales conversion for a high-volume SaaS platform.

PHPHubSpot APIJavaScriptMySQL

SaaS Product Engineering

Shipped multiple high-impact features for a large SaaS messaging platform: a contact card (VCard) builder, segment targeting engine fixes for audience accuracy, subscription management overhaul, self-serve cancellation, plan pricing corrections, and full Heap analytics instrumentation.

PHPJavaScriptMySQLHeapRecurly

Angular SPA

Built features for a startup's Angular/.NET application (admin portals, real-time chat, activity feeds, tutorials, and forms) in close collaboration with founders and designers. Documented versioning processes, testing techniques, and developer best practices.

AngularTypeScript.NETREST APIs

SEO & AEO

Rebuilt a large-scale marketing site end to end: Core Web Vitals optimization, deferred loading, cache busting, schema markup, Open Graph tags, and an AEO strategy that gets content cited in ChatGPT, Perplexity, and Google AI Overviews, with Ahrefs driving keyword and content-gap research.

PHPJavaScriptSchema.orgAhrefs

eCommerce

Built and maintained a mobile-responsive eCommerce platform with custom PHP, theme migration for improved UX and SEO, daily maintenance releases, and consistent performance improvements for a high-visibility retail brand.

WordPressWooCommercePHPJavaScriptCSS

Technical Range

Tools I use to turn product ideas into production systems.

My stack is practical: modern enough to move quickly, grounded enough to keep production systems stable.

Languages & Frameworks

PHPTypeScriptJavaScriptNode.jsReactAngularNext.jsSwift / SwiftUICodeIgniterWordPressHTMLSCSS / CSS

AI Engineering & Primitives

Claude APIOpenAI APIAWS BedrockLLM VisionStructured OutputsPrompt EngineeringAI Agents & SubagentsAgent Skills & HooksMulti-Agent WorkflowsMCPLLM Cost ControlsClaude Code

Databases & Search

MySQLPostgreSQLMongoDBElasticsearchREST APIsWebhooksJWTOAuthMicroservices

Integrations

SalesforceHubSpotStripeRecurlyActiveCampaignSendGridAWeberVertex Tax APIGoogle Maps APIGoogle Places APITwilioreCAPTCHA

DevOps & Cloud

DockerAWSCloudflare WorkersDurable ObjectsCloudflareVarnishGitJenkinsGitLab CI/CDAzure DevOpsElastic BeanstalkAWS LambdaDynamoDBAWS WAFv2AWS CDKAWS SESNginx

Performance, SEO & AEO

Core Web VitalsAEO / AI DiscoveryAhrefsSchema MarkupStructured DataCache StrategyAccessibilityHeapGA / GTMAdobe Analytics

Contact Me.

I am currently focused on a full slate of engineering work and not actively seeking new opportunities. I am always open to interesting technical problems and conversations worth having. If there is a strong reason to get in touch, email me at jshepelsk@gmail.com.