The Problem
You spent an hour yesterday explaining your authentication architecture to Cursor. Today, it suggests the exact approach you rejected. It has no memory of yesterday's conversation.
This is the fundamental limitation of AI coding agents: they're stateless. Every session starts fresh. The context window holds only what you've said in the current conversation, and when you close the session, that knowledge disappears.
Why This Happens
1. No Persistent Storage
AI models don't have built-in memory across sessions. They process your current prompt, generate a response, and forget. There's no database of "things Drew decided" that persists between conversations.
2. Context Window Limits
Even within a session, there's only so much context the model can hold. Long conversations get truncated. Important decisions from earlier in the session can fall out of the window.
3. No Access to External Knowledge
Your AI agent can read your codebase, but it can't read your Slack conversations, your Linear tickets, or the meeting where you decided to use Postgres instead of MongoDB. That context exists, just not where the agent can see it.
Teams report spending 20+ hours per week re-explaining context to AI agents. That's half a developer's time just getting the agent back to where it was yesterday.
What You Lose
- Decision History — Why you chose Stripe over custom payments, why you're not doing SSO yet, why the API is structured that way.
- Customer Context — Who you're building for, what they need, what pain points drive your priorities.
- Rejected Approaches — What you've already tried and why it didn't work. Without this, you waste time re-exploring dead ends.
- Strategic Constraints — Your roadmap, your resource limitations, your compliance requirements.
The Impact
Without persistent context, AI agents make technically correct decisions that are wrong for your product. They suggest features you've explicitly ruled out. They use patterns that don't fit your architecture. They build for generic users instead of your actual customers.
You end up babysitting the agent instead of leveraging it. Every session requires onboarding, like hiring a new contractor who knows nothing about your business.