The Lab – Blog
Practical articles for consequential decisions.
The NJL Design Lab blog publishes source-backed guides, models, and operating systems for financial independence, investing, real estate, family finance, AI, and the non-money side of life.
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Investing
What Is CoastFI? The Simple Math Behind Reaching Financial Independence Without Retiring Early
What CoastFI really means, how the math works, where the assumptions break, and how to stress-test your number before treating it like a plan.
Wealth & FI
How to Stress-Test Your FI Number Before You Trust It
Your FI number can look precise while still being unreliable. Here is how to stress-test the assumptions underneath it — spending, withdrawal, and timing — before you trust…
Wealth & FI
The Real Work in FI Is Not the Number. It’s the Control Loop.
Financial independence gets more durable when you stop treating FI as a static number and start treating it as a repeatable control loop that catches drift, protects optionality,…