Jared shares a six-page prompt from Parahelp, whose AI handles customer support for companies including Perplexity, Replit, and Bolt. Diana describes its role definition, step-by-step plan, tool-call rules, and structured output. The prompt sets company-wide behavior, while customer-specific workflows and examples go into a developer prompt.
State-Of-The-Art Prompting For AI Agents
Speakers
Y Combinator’s Jared, Diana, and Harj discuss prompt engineering, evaluation, and founder-led customer work on The Lightcone podcast.
The hosts describe metaprompting: using a model to revise prompts based on failures, or to create a specialized prompt for a query. For difficult tasks, Jasberry adds expert examples of bugs such as N+1 queries to guide the model. They also recommend letting agents report when information is missing or instructions are unclear, so developers can fix the workflow instead of receiving a guess.
The hosts argue that evaluation data is more valuable than a prompt alone because it explains why the prompt was designed as it was and how to improve it. They recommend learning a customer’s workflow firsthand, then turning those observations into specific tests, such as whether to honor a tractor warranty after an invoice arrives. Understanding those details can give a startup an advantage.
Drawing on Palantir’s forward-deployed engineering model, Jared describes engineers observing customers’ work and building software around real processes. He says founders should do this themselves: listen, build a tailored demo, gather feedback, and return with a working solution. The hosts point to AI startups including Giga ML and HappyRobot as examples of teams using rapid iteration and customer-specific demos to win large deals.
The hosts say models can have different working styles and suit different tasks. Harj reports that, in their scoring example, o3 followed a rubric rigidly, while Gemini 2.5 Pro was more willing to reason about exceptions. They compare prompt work to both programming and managing a person: make expectations and evaluation criteria clear, then improve the process using feedback.
Takeaways
- Structure agent prompts with clear roles, steps, constraints, and output formats.
- Use failed examples to refine prompts, especially when a task is difficult to specify precisely.
- Give agents a way to flag missing information or confusing instructions.
- Build evaluations from direct observation of the customer’s workflow and priorities.
- Founders can win trust by returning quickly with a tailored, working demo.
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What was claimed 11
- integrates with
Parahelp integrates with
Perplexity
“They’re powering customer support for Perplexity”
YouTube Unverified1 source· Talk
- feature
Parahelp: AI customer support
“Parahelp does AI customer support.”
YouTube Unverified1 source· Talk
- feature
Parahelp: Agent prompt is six pages long
“it’s six pages long as we scroll through it”
YouTube Unverified1 source· Talk
- featureTropy: Prompt folding
“they’ve figured out is prompt folding”
YouTube Unverified1 source· Talk
- featureTropy: Prompt and return-value debugging for multistage workflows
“in-depth understanding and debugging of prompts and return values from a multistage workflow”
YouTube Unverified1 source· Talk
- featureJasberry: Automatic bug finding in code
“They build automatic bug finding in code”
YouTube Unverified1 source· Talk
- feature
Gemini 2.5 Pro: Long context window and reasoning traces that can help diagnose prompt misses
“you can learn a lot about misses by looking at the thinking traces”
YouTube Unverified1 source· Talk
- feature
Palantir: Institutionalized and scaled forward-deployed engineering
“Palantir was probably the first company to institutionalize that and scale it as a process”
YouTube Unverified1 source· Talk
- featureHappy Robot: AI voice agents
“They build AI voice agents.”
YouTube Unverified1 source· Talk
- feature
Gemini 2.5 Pro: Applies scoring rubrics flexibly and reasons about exceptions
“Gemini 2.5 Pro was quite good at being flexible”
YouTube Unverified1 source· Talk
- feature
o3: Applies scoring rubrics rigidly and penalizes mismatches
“o3 was very rigid. It really sticks to the rubric”
YouTube Unverified1 source· Talk









