AI will rewrite the codebase

Replace the working system instead of strangling it. A perennial money pit with new branding each decade.

$ "We'll freeze features and rewrite in the hot language." Multi-year projects shipped late, incomplete, or not at all — while competitors iterated on the ugly system that made money.

LangChain-class glue mutated into MCP clients and thin wrappers around vendor APIs. The durable pieces are still boring: evals, retrieval, and product UX.

Coding agents that edit the repo — now table stakes. Generation outran review capacity; ownership is the bottleneck.

Accept AI output on feel, skip the diff, hope tests exist. Fast demos; CVEs and nobody owns the middleware.

$ Ship-to-prod without reading the diff became a flex until incidents revealed nobody knew which prompt wrote the auth middleware. Review debt arrived in one weekend demo.

LangGraph, CrewAI, AutoGPT cosplay — then vendor harnesses shipped the same loop as an API. Open-source swarms faded; leased orchestration stuck.

$ Autonomous agent swarms burned API budgets on coordination loops that a single prompt and a cron job would have handled. Debugging "which agent lied" became the new on-call sport.

The Codex/Claude loop as a product SKU — durable sessions, compaction, subagents, and a sandbox you do not own.

$ Teams replaced a weekend of LangGraph glue with a managed session API, then discovered residency, recovery, and kill switches all live on the vendor side of the harness.