JonLuca's Blog

I crawled the top 1,000 sites and read their response headers.

AI models may bring back the ability to combine deep expertise from every field toward a single goal.

I built a fine dining tracker app using React Native, and the experience was surprisingly smooth, both from how good React Native has gotten, and how much better the models are.

Why financial markets are an unusually pure, brutal, and adversarial reinforcement learning environment.

Automating SkyCards, the FlightRadar24 plane‑spotting game

Reverse engineering the California DMV's license plate availability checker to find cool custom plates.

Improving PyTorch model loading performance using memory-based filesystems and distributed storage in Kubernetes.

Using latency measurements to infer when a globally used application is served only from us-east-1.

Examining passwordless Magic Link authentication and the implementation exposed in its onboarding flow.

Building semantic search and conversation analysis for an exported iMessage archive.

Automating Verizon number searches to find rare phone numbers with repeating digits.

Finding and disclosing vulnerabilities in Metaplex Candy Machine NFT minting contracts.

Using browser heap snapshots to recover structured data after network responses have been encrypted.

A tour of surprising JavaScript behavior involving functions, coercion, arrays, and language edges.

Controlling concurrency with asyncio and semaphores to make large batches of Python HTTP requests fast.

A minimal server-rendered starter setup for Vite, React 17, and TypeScript 4.3.

Claiming a Handshake developer airdrop and turning an unexpected token allocation into cash.

How Apple's large address allocation can interact unexpectedly with VPN routing and airplane Wi-Fi.

An accessible explanation of tax-loss harvesting, wash sales, and portfolio tradeoffs.

Reverse-engineering Zogo reward redemption requests and finding a profitable validation flaw.

Configuring self-hosted Matomo analytics behind custom routes and POST tracking.

Investigating an airline Wi-Fi authentication flow that granted T-Mobile connectivity.

A look back at living in a coliving community during the first year of COVID-19.

Examining how airline loyalty currencies shape American Airlines as much as flying passengers does.

Reflections on product engineering, growth work, experimentation, and building for user behavior.

Reverse-engineering Lyft's ride-history APIs to analyze six years of personal trips.

How the Nintendo Switch uses irreversible hardware fuses to prevent firmware downgrades.

Comparing Promise.all and Promise.allSettled for concurrent JavaScript workflows and failures.

Investigating why Goodreads pages responded slowly and what its requests revealed.

Restoring paste, context menu, and selection actions on websites that disable them.

Estimating the storage required to preserve every word humans have ever spoken.

Why small automations are valuable because they preserve focus, not merely because they save keystrokes.

A year of travel summarized through flights, mileage, routing, and memorable stops.

Investigating onboard flight entertainment APIs, flight telemetry, and Widevine-protected media.

Studying SPF, DKIM, and DMARC adoption and behavior across real-world email domains.

Reverse-engineering Safeway's coupon APIs to automate adding digital offers to an account.

Exploring an Ember application's data layer to find discontinued Dollar Shave Club products.

Scraping and analyzing activity patterns in the credit-card churning subreddit.

Analyzing compensation packages from 2019 new-graduate technology job offers.

A collection of practical shell aliases and functions for faster daily command-line work.

Using probability to compare a broken clock with one that is consistently five minutes slow.

Planning and taking an ANA round-the-world business-class award itinerary across Asia and Europe.

Finding application state and implementation clues by comparing unexpected browser global variables.

Inspecting exposed experiment APIs to understand how growth teams test product changes in production.

Reverse-engineering an obfuscated American Express phishing campaign from email to exfiltration endpoint.

How a student scheduling project drew a cease and desist and unexpectedly started earning money.

Building a Chrome extension to retrieve and analyze personal Uber trip history.

Using graph theory and Ryanair route data to find cheap multi-city flight loops through Europe.

An introduction to credit card rewards, sign-up bonuses, and the mechanics of churning.

Exploring bandwidth, filtering, and compression to reproduce the distinctive sound of phone calls.