LLMs have hit a wall by scraping nearly all available public data. The next phase of AI development and competitive differentiation will come from training models on high-quality, proprietary data generated by human experts. This creates a booming "data as a service" industry for companies like Micro One that recruit and manage these experts.

To move beyond general knowledge, AI firms are creating a new role: the "AI Trainer." These are not contractors but full-time employees, typically PhDs with deep domain expertise and a computer science interest, tasked with systematically improving model competence in specific fields like physics or mathematics.

Rather than relying on a single LLM, LexisNexis employs a "planning agent" that decomposes a complex legal query into sub-tasks. It then assigns each task (e.g., deep research, document drafting) to the specific LLM best suited for it, demonstrating a sophisticated, model-agnostic approach for enterprise AI.

Unlike coding with its verifiable unit tests, complex legal work lacks a binary success metric. Harvey addresses this reinforcement learning challenge by treating senior partner feedback and edits as the "reward function," mirroring how quality is judged in the real world. The ultimate verification is long-term success, like a merger avoiding future litigation.

To ensure product quality, Fixer pitted its AI against 10 of its own human executive assistants on the same tasks. They refused to launch features until the AI could consistently outperform the humans on accuracy, using their service business as a direct training and validation engine.

Successful vertical AI applications serve as a critical intermediary between powerful foundation models and specific industries like healthcare or legal. Their core value lies in being a "translation and transformation layer," adapting generic AI capabilities to solve nuanced, industry-specific problems for large enterprises.

Mercore's $500M revenue in 17 months highlights a shift in AI training. The focus is moving from low-paid data labelers to a marketplace of elite experts like doctors and lawyers providing high-quality, nuanced data. This creates a new, lucrative gig economy for top-tier professionals.

A top-tier lawyer’s value mirrors that of a distinguished engineer: it's not just their network, but their ability to architect complex transactions. They can foresee subtle failure modes and understand the entire system's structure, a skill derived from experience with non-public processes and data—the valuable 'reasoning traces' AI models lack.

While AI "hallucinations" grab headlines, the more systemic risk is lawyers becoming overly reliant on AI and failing to perform due diligence. The LexisNexis CEO predicts an attorney will eventually lose their license not because the AI failed, but because the human failed to properly review the work.