All Articles
I Ran 1,000 App Store Reviews Through Claude API — Here's What My Data Was Hiding
Lessons from 10+ years of indie app development and 50M+ downloads: how to use Claude API to batch-analyze App Store reviews, auto-generate improvement priorities, and fix the blind spots human reading creates.
Combining Haiku 4.5, Streaming, and Prompt Caching to Cut Costs in a Personal App — An Implementation Record
A hands-on record of combining Claude Haiku 4.5, streaming, and prompt caching to improve both cost and response speed in a personal iOS/Android app — including the mistakes made along the way.
What metadata.user_id in the Claude API Is Actually For — Designing the Abuse-Detection vs. Privacy Trade-off
The metadata.user_id field in the Messages API exists to sharpen abuse detection, but sending raw email addresses creates a privacy problem. Here is the HMAC-based stable pseudo-ID pattern I use, plus a clear set of rules for when to send it and when not to.
Bulletproof JSON Output with Claude API Prefill: A Four-Layer Defense Pattern from Indie SaaS
How I went from late-night JSON parse failures to a 100% parse success rate across thousands of monthly Claude API requests. Working code in TypeScript and Python, plus production numbers from an indie SaaS.
A Five-Layer Preflight Design for Claude API — How I Cut Hundreds of 400/422/529 Errors to Zero
A production-tested five-layer preflight design that catches Claude API failures before the network call — schema, token budget, model capability, content policy, and spend cap — with full TypeScript implementation and one month of operational numbers.
Type-Safe Claude API Tool Calling with Zod: Patterns for TypeScript Developers
How to implement Claude API tool calling with TypeScript and Zod for full type safety. Covers schema-to-API conversion, runtime validation, and three common pitfalls with practical code examples.
Implementing the Saga Pattern in Claude Agent SDK — Compensating Transactions and Idempotency
A practical guide to building safe multi-step Claude Agent SDK workflows. We cover compensating transactions, idempotency keys, and partial-failure state recovery, all from patterns that have run in production.
Implementing the Transactional Outbox Pattern with Claude Agent SDK — Eliminating Lost Side Effects in Production
Stop the 'the row was inserted but the email never went out' class of bugs in Claude Agent SDK apps. A production-grade walkthrough of the Transactional Outbox pattern using Postgres and Cloudflare Queues.
Maximizing Profit Margins with Claude Haiku / Sonnet / Opus Model Switching
A complete implementation guide for dynamically routing Claude API requests to the right model based on task complexity. Includes cost calculation formulas, routing engine code, quality fallback logic, and real-world margin impact data.
The AI Sales Automation Your Team Actually Wants — Building a Multi-Agent Sales System with Claude Agent SDK
A complete guide to building a production-grade multi-agent sales automation system using Claude Agent SDK — covering lead scoring, proposal drafting, human review gates, CRM integration, and cost optimization with real code examples.
Building an Autonomous Research Agent with Claude API: Web Search, Summarization, and Knowledge Management
A complete guide to designing and implementing an autonomous research agent using Claude API and web search tools. Covers budget control, quality assurance, and knowledge base storage for production use.
Claude API × Python in Practice: Building an AI Assistant with Tool Calling and Streaming
A practical guide to combining Claude API's Tool Use and Streaming in Python. Build a working AI assistant with real tool execution, complete source code included, plus a breakdown of the tricky parts that trip up most developers.