🦄 No Vibes Allowed - Building Design Docs with AI
In this month's no vibes allowed episode, Vaibhav will show how he uses AI to make design docs for complicated tasks by building out an actual design doc for a feature in BAML. As always for our no vibes allowed series, we will be solving real problems in real production systems.
Project Details
Open in GitHubIn this month's No Vibes Allowed episode, Vaibhav shows how he uses AI to build design docs for complicated tasks by working through an actual design doc for a threading system in BAML. Real code, real trade-offs, real production systems.
Episode Highlights
"Implementation can often be one-shot if the design is phenomenally correct. But phenomenally correct design is very hard to do."
"We generate slop code and don't care what it does. As long as the workflow is good, we're very happy. This is what we mean by fighting slop with slop."
"The call site determines if it's happening concurrently or not. That's the key insight — we don't want function coloring forcing async all the way up the stack."
"When you're doing an incredibly hard problem, good design can break it into four or five chunks that are each individually one-shot implementable."
Key Takeaways
- Design docs pay off at implementation time. When a design is thorough and correct, coding agents can one-shot individual chunks. Spending days in design is not wasted time — it's scope reduction.
- Fight slop with slop. Internal tooling doesn't need to be clean. Build quick, AI-generated tools to manage design docs, keep them reviewable, and connect them to Slack — then let coding agents maintain that tooling so you never have to.
- The problem of "colored functions" is real in agentic systems. When async needs to propagate all the way up the call stack, it creates massive diffs. Design your concurrency model to let the call site decide, not the function signature.
- BEPs (BAML Enhancement Proposals) are a concrete pattern for structured design thinking. Each BEP documents why a feature is needed, the trade-offs considered, and what decision was made — giving AI models rich context when implementing.
- Involve your team by making design docs readable. GitHub isn't built for sharing large markdown files with comments. A simple internal dashboard with Slack integration makes design review a habit rather than a chore.
Resources
- Session Recording
- GitHub Repo
- Discord Community
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All Episodes
Feature Flag Everything?
This week, the top headline is vibe coders realizing that they can use feature flags to ship experimental (read: slop) features to production without impacting all customers. Shipping code is a lot harder when everything is changing all the time. Feature flags can be a good technique to test various things, but how do you set that up? Do you feature flag new models? New prompts? New harnesses? We'll dive into details here and see where feature flags improve your product delivery vs. just giving you an excuse to ship more slop.
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OpenAI tells you not to build your own harness
Harness engineering is all the hype now, so on this week on the podcast we're looking back to an article written by OpenAI in February about harness engineering, "Harness engineering: leveraging Codex in an agent-first world". In this article, they claim that the era of "hand-written code" is officially over. We break down their experiment of shipping a million-line product with zero manual coding, shifting the human role from "coder" to "environment designer."
Harness Engineering Without the Hype
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No Vibes Allowed March Edition
This week on the podcast is our March episode of our no vibes allowed series! Join us to watch how we implement everything we discuss on a weekly basis in our company's product. Real code, real trade-offs, and real production systems
MCP is Dead?
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Prompt Injections Guardrails
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PII Redaction and Sensitive Data Scrubbing
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No Vibes Allowed February
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AI Content Pipeline Revisited
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Agentic Backpressure Deep Dive
In our next installment of advanced coding agent workflows, we'll explore some alternatives to research for improving results from coding agents. Code and web research is great for understanding the current codebase and finding documentation, but neither of these things is as concrete, and can still lead to hallucinations or incorrect assumptions. In this episode, we'll talk about learning tests and proof-driven-dev - writing small PoC programs and tests that lay the groundwork to confirm understanding of external systems, *before* you get deep into implementation. This will extend our previous conversation about agentic backpressure and building deterministic feedback loops to help coding agents work more autonomously.
Prompting Is Becoming a Product Surface
Prompting used to be an engineering problem. Write the right string, tweak it until the model behaves, ship it behind the scenes. That breaks the moment real users show up. Customers don't think in prompts — they think in goals. They want to explain what they're trying to accomplish, not debug a magic sentence. So prompting is moving into the product. Interfaces matter. Structure matters. Guardrails and feedback matter. The real work now isn't prompt cleverness — it's building systems that let people express intent in a way software can actually understand and trust.
No Vibes Allowed
We received great feedback from our previous live coding sessions, so this week we are bringing it back this week by live streaming while we add more features to BAML. We have discussed a lot of topics over the past several months, and we will be digging into the how to put many of these concepts into practice as we build out actual features in the product.
Email is All You Need
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Applying 12-Factor Principles to Coding Agent SDKs
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Understanding Latency in AI Applications
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Founding Boundary: Vaibhav's Journey
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Founding HumanLayer: Dex's Journey
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Git Worktrees for AI Coding Agents
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Multimodal Evals
Building evals for multimodal AI - testing vision models, document understanding, and image analysis with structured evaluation frameworks.
No Vibes Allowed: Using CodeLayer to Build CodeLayer
Live coding with CodeLayer, we'll use Research / Plan / Implement live to ship 3 new features to CodeLayer.
Building an Animation Pipeline
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Dates, Times, and LLMs
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Event-driven agentic loops
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Ralph Wiggum under the hood: Coding Agent Power Tools
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Agentic RAG + Context Engineering
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Anthropic Post Mortem
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Dynamic Schemas
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Evals for Classification
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Bash vs. MCP - token efficient coding agent tooling
In this conversation, Dex and Vaibhav delve into the intricacies of coding agents, focusing on the debate between using MCP (Model Control Protocol) and Bash for tool integration. They explore the importance of understanding context windows, token management, and the efficiency of using different tools. The discussion emphasizes the significance of naming conventions, dynamic context engineering, and the engineering efforts required to optimize performance. They also share real-world applications, best practices for using MCPs, and engage with the community through a Q&A session.
Generative UIs and Structured Streaming
We'll explore hard problems in building rich UIs that rely on streaming data from LLMs. ​Specifically, we'll talk through techniques for rendering **STRUCTURED** outputs from LLMs, with real-world examples of how to handle partially-streamed outputs over incomplete JSON data. We'll explore advanced needs like * Fields that should be required for stream to start * ​Rendering React Components with partial data ​* Handling nullable fields vs. yet-to-be-streamed fields * ​Building high-quality User feedback * ​Handling errors mid-stream
Voice Agents and Supervisor Threading
Exploring voice-based AI agents and supervisor threading patterns for managing complex conversational workflows.
Claude for Non-Code Tasks
On #17 we talked about advanced context engineering workflows for using Claude code to work in complex codebases. This week, we're gonna get a little weird with it, and show off a bunch of ways you can use Claude Code as a generic agent to handle non-coding tasks. We'll learn things like: Skipping the MCP and having claude write its own scripts to interact with external systems, Creating internal knowledge graphs with markdown files, How to blend agentic retrieval and search with deterministic context packing
Interruptible Agents
Anyone can build a chatbot, but the user experience is what truly sets it apart. Can you cancel a message? Can you queue commands while it's busy? How finely can you steer the agent? We'll explore these questions and code a solution together.
Decoding Context Engineering Lessons from Manus
A few weeks ago, the Manus team published an excellent paper on context engineering. It covered KV Cache, Hot-swapping tools with custom samplers, and a ton of other cool techniques. On this week's episode, we'll dive deep on the manus Article and put some of the advice into practice, exploring how a deep understanding of models and inference can help you to get the most out of today's LLMs.
Context Engineering for Coding Agents
By popular demand, AI That Works #17 will dive deep on a new kind of context engineering: managing research, specs, and planning to get the most of coding agents and coding CLIs. You've heard people bragging about spending thousands/mo on Claude Code, maxing out Amp limits, and much more. Now Dex and Vaibhav are gonna share some tips and tricks for pushing AI coding tools to their absolute limits, while still shipping well-tested, bug-free code. This isn't vibe-coding, this is something completely different.
Evaluating Prompts Across Models
AI That Works #16 will be a super-practical deep dive into real-world examples and techniques for evaluating a single prompt against multiple models. While this is a commonly heralded use case for Evals, e.g. 'how do we know if the new model is better' / 'how do we know if the new model breaks anything', there's not a ton of practical examples out there for real-world use cases.
PDFs, Multimodality, Vision Models
Dive deep into practical PDF processing techniques for AI applications. We'll explore how to extract, parse, and leverage PDF content effectively in your AI workflows, tackling common challenges like layout preservation, table extraction, and multi-modal content handling.
Implementing Decaying-Resolution Memory
Last week on #13, we did a conceptual deep dive on context engineering and memory - this week, we're going to jump right into the weeds and implement a version of Decaying-Resolution Memory that you can pick up and apply to your AI Agents today. For this episode, you'll probably want to check out episode #13 in the session listing to get caught up on DRM and why its worth building from scratch.
Building AI with Memory & Context
How do we build agents that can remember past conversations and learn over time? We'll explore memory and context engineering techniques to create AI systems that maintain state across interactions.
Boosting AI Output Quality
This week's session was a bit meta! We explored 'Boosting AI Output Quality' by building the very AI pipeline that generated this email from our Zoom recording. The real breakthrough: separating extraction from polishing for high-quality AI generation.
Building an AI Content Pipeline
Content creation involves a lot of manual work - uploading videos, sending emails, and other follow-up tasks that are easy to drop. We'll build an agent that integrates YouTube, email, GitHub and human-in-the-loop to fully automate the AI that Works content pipeline, handling all the repetitive work while maintaining quality.
Entity Resolution: Extraction, Deduping, and Enriching
Disambiguating many ways of naming the same thing (companies, skills, etc.) - from entity extraction to resolution to deduping. We'll explore breaking problems into extraction → resolution → enrichment stages, scaling with two-stage designs, and building async workflows with human-in-loop patterns for production entity resolution systems.
Cracking the Prompting Interview
Ready to level up your prompting skills? Join us for a deep dive into advanced prompting techniques that separate good prompt engineers from great ones. We'll cover systematic prompt design, testing tools / inner loops, and tackle real-world prompting challenges. Perfect prep for becoming a more effective AI engineer.
Humans as Tools: Async Agents and Durable Execution
Agents are great, but for the most accuracy-sensitive scenarios, we some times want a human in the loop. Today we'll discuss techniques for how to make this possible. We'll dive deep into concepts from our 4/22 session on 12-factor agents and extend them to handle asynchronous operations where agents need to contact humans for help, feedback, or approvals across a variety of channels.
12-factor agents: selecting from thousands of MCP tools
MCP is only as great as your ability to pick the right tools. We'll dive into showing how to leverage MCP servers and accurately use the right ones when only a few have actually relevant tools.
Policy to Prompt: Evaluating w/ the Enron Emails Dataset
One of the most common problems in AI engineering is looking at a set of policies/rules and evaluating evidence to determine if the rules were followed. In this session we'll explore turning policies into prompts and pipelines to evaluate which emails in the massive Enron email dataset violated SEC and Sarbanes-Oxley regulations.
Designing Evals
Minimalist and high-performance testing/evals for LLM applications. Stay tuned for our season 2 kickoff topic on testing and evaluation strategies.
Twelve Factor Agents
Learn how to build production-ready AI agents using the twelve-factor methodology. We'll cover the core concepts and build a real agent from scratch.
Code Generation with Small Models
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Reasoning Models vs Reasoning Prompts
Models can reason but you can also reason within a prompt. Which technique wins out when and why? We'll find out by adding reasoning to an existing movie chat agent.
Large Scale Classification
LLMs are great at classification from 5, 10, maybe even 50 categories. But how do we deal with situations when we have over 1000? Perhaps it's an ever changing list of categories?