Ed McCormic Source on GitHub

AI build specifications

By Ed McCormic

The plans behind 52 things I've built with Claude Code and Cursor since February 2026. 42 have shipped, and 29 have public code on GitHub.

Build timeline

One block per spec, on the day it started. Hover a block to see which one.

System design builds

Full-stack versions of Hello Interview breakdowns, local on LocalStack, deployable to AWS.

  1. Spark (Tinder) (public code) Swipes, matches, and a geo-filtered feed with atomic Redis swipe pairs and real-time match notifications. shipped
  2. Corner (Gopuff local delivery) One-hour delivery that never oversells stock, with partitioned inventory and a read replica, from the Hello Interview Gopuff breakdown. shipped
  3. Kindling (Tinder, second take) A second Tinder-style build using PostGIS and an SNS-to-SQS pipeline for live match events. shipped
  4. distcache A sharded, replicated LRU cache with consistent hashing and hot-key mitigation, plus a dashboard to watch it work. shipped
  5. Local Eats (Yelp) (public code) Business search and reviews with PostGIS geo queries and Postgres full-text search, from the Hello Interview Yelp breakdown. shipped
  6. Frontrow (Ticketmaster) (public code) Event ticketing with seat locks, a virtual waiting room, and cached search, built from the Hello Interview Ticketmaster breakdown. shipped
  7. Printroom (Instagram) (public code) Photo and video posts with direct-to-S3 uploads and a hybrid fan-out feed, from the Hello Interview Instagram breakdown. shipped
  8. Bitly URL shortener (public code) Short links with a Redis counter for code generation and a cached redirect path, from the Hello Interview Bitly breakdown. shipped
  9. TocketMaster (Ticketmaster, first take) (public code) The first Ticketmaster build, with four Spring Boot services behind nginx, Redis seat holds, and Postgres optimistic concurrency so a seat can't be sold twice. shipped

Spring Boot and Java deep dives

One article or concept per project, rebuilt as running code with tests.

  1. Orchestration-based Saga (public code) A central orchestrator drives payment, inventory, and compensating refunds over Kafka, with config from AWS (LocalStack locally). in progress
  2. Spring Boot Transactions (public code) A small bank API where each @Transactional pitfall has a demo endpoint that shows the bug, and the same endpoint with ?fixed=true shows the fix. shipped
  3. Spring @Async + @Retryable The same retry scenarios implemented twice, with the spring-retry library and with Spring Framework 7's built-in @Retryable. shipped
  4. Java fundamentals workbook (public code) Exercises with tests for shallow vs deep copy and abstract classes vs interfaces, including the diamond conflict. shipped
  5. Custom Java DI + AOP framework (public code) A tiny dependency-injection container and AOP proxy built from scratch to understand what Spring does under the hood. shipped
  6. high-rps-api (public code) A Spring Boot API designed to scale toward 1M requests/second, with layered caching, load tests, and TTL jitter experiments. shipped
  7. Factory Pattern API (public code) Notification and payment APIs that pick an implementation through Spring-managed factories. shipped
  8. Event-driven commerce with Kafka (public code) Orders, inventory, payment, and notifications using a transactional outbox, idempotent consumers, and compensation flows. shipped
  9. Spring Boot + Elastic Observability (public code) InfoWorld's Elastic Cloud observability walkthrough rebuilt to run entirely in Docker Compose. shipped
  10. API Failure Lab (public code) A Spring Boot API built to break, where every failure mode is reproducible, observable with real tools, and paired with a fix. shipped
  11. Advanced Logging Patterns (public code) Recreates a "money debited, order not created" incident so the whole story can be read by filtering on one requestId in Kibana. shipped
  12. SpringMarket (public code) A marketplace modular monolith designed to teach the major Spring technologies inside one realistic domain instead of separate demos. in progress
  13. Products REST BFF over gRPC (public code) A review of an existing Spring Boot gRPC + REST project, with best-practice fixes and a Postgres backing store. shipped
  14. gRPC Product API (public code) A Spring Boot 4.1 gRPC service for product CRUD and stock adjustment on Postgres, the backend behind the Products REST BFF. shipped
  15. gRPC Order Platform (public code) A gRPC order service and a WebFlux REST edge that calls it, with production concerns implemented for real. shipped
  16. Design Patterns in Spring Boot (public code) A runnable teaching app with 19 design patterns, each with its own endpoint, a behavioural test, and an honest write-up of its costs. shipped

Interview prep and study

Portfolio pieces built for specific roles, and study projects for the topics they test.

  1. Step-up wallet (BFF) (public code) A React wallet whose Spring Boot backend-for-frontend signs in with the auth service and requires a recent MFA before payments. shipped
  2. Voice enrollment and verification Enroll a speaker, store a voiceprint, and verify new samples, with spoof detection, ASR challenge phrases, and FAR/FRR measurement. shipped
  3. OAuth2 / OIDC auth service (public code) An authorization server with TOTP and passkey MFA, step-up auth, refresh-token reuse detection, and JWKS rotation, built tests-first. shipped
  4. Loan Pipeline Dashboard Loan applications move through underwriting under a role-authorized state machine, with an audit trail, optimistic locking, and a live event stream. shipped
  5. Spring Batch walkthrough A Spring Batch API with RetryTemplate and concurrency where it helps, documented function by function for an interview. archived
  6. React movie app (public code) A tutorial movie app extended with context, a store, custom hooks, and a hooks guide explaining what, how, why, and the pitfalls of each. shipped
  7. React CRUD Lab (public code) A Vite + React 19 + TypeScript learning app that does full CRUD against JSONPlaceholder, with a learning guide alongside the code. shipped
  8. Payments CRUD (React 19 + Spring Boot 3) An intermediate full-stack CRUD app with a detailed walkthrough of how React 19 and Spring Boot interact. archived
  9. Harborpath Recordkeeping (public code) An Angular Native Federation micro-frontend with a Spring Boot API for a fictional 401(k) and 529 recordkeeping platform. shipped
  10. SQL Top 50 study database (public code) A local Postgres database with a schema, sample rows, a practice worksheet, and a solution for each of LeetCode's Top SQL 50 problems. shipped
  11. Spring interview study series A multi-phase study repo, one topic area per phase, where every claim in the docs is backed by a test. in progress
  12. Kafka e-commerce microservices (public code) Four services and five topics demonstrating idempotent producers, manual commits, DLQs, retries, and partitioning by key. shipped

Websites and games

Sites, browser games, and front-end experiments.

  1. Personal site A personal homepage built around Ohio State football, Formula 1, NASCAR, and software, with live schedules and links to my projects. in progress
  2. SkyQuest A browser flight simulator with a Cessna 172 and an F-16, glass-cockpit styling, synthesized engine audio, and missions. shipped
  3. Cybercraft Dungeons A Minecraft Dungeons–style browser crawler starring blocky Autobots, set in a Cybertron-inspired city. shipped
  4. swiftbeard OS A portfolio styled as an operating system in the browser, with windows, themed wallpapers, playable games, and animated API-flow demos. in progress
  5. Fooddoneit PWA audit A code health review of an existing Vue + Vuetify PWA backed by AWS Cognito, done on a new feature branch. shipped
  6. Ed's blog and link library A Next.js MDX blog that also stores my saved links, with a sweep that imports links I've emailed to myself. shipped

Mobile apps

Native SwiftUI and React Native apps.

  1. Scanty An iOS document scanner that saves to iCloud as PDF or image and turns handwritten notes into typed text with OCR. shipped
  2. BricksterRN A React Native version of Brickster that identifies LEGO pieces on-device with YOLO detection, MobileCLIP zero-shot matching, and live AR boxes. in progress
  3. Brickshot An Expo app that turns a few photos of an object into a LEGO-style mosaic preview and a buildable parts plan. shipped
  4. Brickster An iOS app that uses the camera, AR, and on-device ML to find the LEGO pieces for a set and track which ones you've collected. in progress
  5. AuroraHIT An iOS 26 SwiftUI app that tells you when the aurora may be visible where you are, using NOAA data and no backend. shipped

Tools and automation

Small utilities that save me time.

  1. AI Build Specifications site (public code) A GitHub Pages site for storing the specifications behind projects built with Claude Code and Cursor. shipped
  2. The Repo Index Sign in with GitHub to see every repo you own, sorted into categories, with READMEs rendered in a typeset viewer and stars used as bookmarks. shipped
  3. c-resume Paste a job description on my phone; Claude tailors my resume and my Mac fills in the application for me to review and approve. in progress
  4. Aurora Alert SMS alerts when the aurora may be visible at your zip code, from a cron job that checks NOAA's Kp index every 30 minutes. shipped