Stop rebuilding agents: how I’m using “folder as app” + 60/30/10 to make stacks survive model changes
Every time a new model or agent framework drops, I feel the urge to burn everything down and rebuild. New tool, new “agent,” same problem: my workflows, prompts, and SOPs end up glued to the tool instead of the work. What finally started working was flipping the mental model: The folder is the app. The AI is just the worker that knows how to navigate it. Under the hood I’m using a simple architecture that does two things: Separates what should be code, what should be rules, and what actually needs AI Structures everything so any model can plug in later without a rebuild I think of it as 60 / 30 / 10 on top of a 3‑layer workspace. Step 1: 60 / 30 / 10 – decide where AI actually belongs For every task, I force it into one of three buckets: 60% – Automations (no AI at runtime) Same input → same output every time. Scripts, API calls, cron jobs, database writes. AI can help write the script, but the script runs it. 30% – Rule engines (templates / decision trees) Clear if/then logic, multiple branches, but all map‑able. Triage, routing, form logic, templated replies. Once the tree exists, it runs without “thinking.” 10% – Prompts (actual AI work) Summaries, syntheses, ambiguous inputs, creative drafting, nuanced judgment. This is the only layer where I want the model to “think.” If I can’t decide, I decompose the task until each step is clearly one of those three. That alone kills a ton of “let’s just build an agent” impulses. Step 2: 3‑layer folder architecture Once tasks are classified, everything lives in a single workspace: Layer 1 – The map (router) One root markdown file, e.g. _router.md or WORKSPACE.md: Explains the business / project in plain language Lists folders and what they’re for Defines naming conventions (this is your “schema”) Has a routing table: “If task = X, read these files, skip those, write output here, load these skills.” When I start a session I don’t paste giant prompts. I say: “Read _router.md and follow it.” Layer 2 – Task workspaces by layer