Engineering notes begin with an actual build, failure, or release task.
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Test the system.
Ship with evidence.
Engineering guides, AI research, and free planning tools for independent builders. Every page must solve a concrete problem and expose its sources, assumptions, and limits.
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Fault-Testing Bilingual SEO in a Next.js App Router SiteEngineering · 9 min read · A verifiable bilingual release workflowExternal facts link to primary sources, with facts, analysis, and unknowns kept distinct.
Pages show review dates; material that cannot be maintained reliably leaves the public index.
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01 · AI
Build a Repeatable LLM Agent Evaluation Before You Pick a Model
A practical evaluation design for comparing coding and tool-using models on the work your product actually needs.
Read the note →02 · EngineeringWhat I check before shipping a Next.js site to production
A practical release review covering routes, metadata, accessibility, performance, and the small failures that are easy to miss.
Read the note →03 · MoneyHow Much Emergency Fund Do You Need? A Practical Sizing Framework
Move beyond a generic three-to-six-month rule with a staged method based on essential spending, income risk, insurance gaps, and access to cash.
Read the note →USEFUL STARTING POINTS
Start with one concrete question
01
What to check before shipping a Next.js site
Use a release evidence matrix to check real routes, metadata, failure behavior, and rollback.
Open page →02The small tools that save me hours every week
Start with small automations that reduce repeated work and keep a manual fallback.
Open page →03Compound interest calculator
Explore how starting balance, recurring contributions, assumptions, and time interact.
Open page →DEEP RESEARCH
Go beyond the update.
Follow the evidence.
Long-form reports on AI systems, software delivery, and financial resilience for independent builders—with scope, sources, limits, and maintenance triggers made explicit.
Explore the research library ↗CORE TOPICS
Practical systems for independent builders
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Engineering
Ship software with release evidence, recovery paths, and maintainable architecture.
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Latest maintained notes
✦FIELD NOTE / 001
Build a content site that lasts: a practical architecture for solo makers
A calm, repeatable system for publishing technical notes, tools, and guides without creating a maintenance burden.
Read the note ↗A beginner's guide to thinking about index funds
SSH Host Key Changed: A Safe Recovery Guide for Rebuilt Servers and Reused IPs
From AdSense Low-Value Content Rejection to a Repeatable Quality Gate
Fault-Testing Bilingual SEO in a Next.js App Router Site
The small tools that save me hours every week
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Publish less.
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aifincode is built and maintained independently by Luo Jie. AI may assist research and checks, while the author remains responsible for topics, sources, facts, code, and every publication decision.
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