When to Use Unit vs Integration Tests in Node.js
Learn to choose unit or integration tests in Node.js by the behavior and boundary that must stay real, without following a fixed ratio.
Accepting new clients
You run the business.
I handle the software.
I'm Samuel Fajreldines, a senior software engineer. Growing U.S. businesses hire my team to become their software department, not a vendor they rehire every quarter. I set the technical direction, my team builds and ships, and I stay accountable for everything that goes out.
- From $5,000/month
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Books
Development Harness
Software engineering with AI agents, from the first contract to production.
A field guide for designing, constraining and verifying AI agents in real software systems, with practical workflows, safety gates and enterprise operations.
Read the book
Software Engineering Blog
In-depth guides, tutorials and real-world engineering write-ups by Samuel Fajreldines on JavaScript & TypeScript, Node.js, Artificial Intelligence, DevOps, Serverless, testing and software architecture.
Latest Articles
How to Validate External JSON Before Using It in TypeScript
Learn to treat external JSON as unknown, validate nested objects, separate parsing from shape checks, and test the TypeScript boundary.
How to Compare Software Development Proposals Before Signing
Compare software proposals by outcome, scope, delivery proof, ownership, maintenance, and exit before you sign.
When Should a Small Business Replace Its Scheduling Spreadsheet?
Learn when a scheduling spreadsheet still works and when shifts, availability, messages, and competing versions need a more reliable process.
AI agent context compaction: what to preserve before continuing
Learn what an AI agent can summarize, what must live outside its history, and how to verify task state after context compaction.
