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Nicolay here,
most AI conversations obsess over capabilities. This one focuses on constraints - the right ones that make AI actually useful rather than just impressive demos.
Today I have the chance to talk to Dexter Horthy, who recently put out a long piece called the “12-factor agents”.
It’s like the 10 commandments, but for building agents.
One of it is “Contact human with tool calls”: the LLM can call humans for high-stakes decisions or “writes”.
The key insight is brutally simple. AI can get to 90% accuracy on most tasks - good enough for spam-like activities but disastrous for anything that requires trust. The solution isn't to wait for models to get smarter; it's to add a human approval layer for critical actions.
Imagine you are writing to a database or sending an email. Each “write” has to be approved by a human. So you post the email in a Slack channel and in most cases, your sales people will approve. In the 10%, it’s stopped in its tracks and the human can take over. You stop the slop and get good training data in the mean time.
Dexter’s company is building exactly this: an approval mechanism that lets AI agents send requests to humans before executing.
In the podcast, we also touch on a bunch of other things:
💡 Core Concepts
📶 Connect with Dexter:
📶 Connect with Nicolay:
⏱️ Important Moments
🛠️ Tools & Tech Mentioned
📚 Recommended Resources
🔮 What's Next
Next week, we will continue going more into getting generative AI into production talking to Vibhav from BAML.
💬 Join The Conversation
Follow How AI Is Built on YouTube, Bluesky, or Spotify.
If you have any suggestions for future guests, feel free to leave it in the comments or write me (Nicolay) directly on LinkedIn, X, or Bluesky. Or at [email protected].
I will be opening a Discord soon to get you guys more involved in the episodes! Stay tuned for that.
♻️ I am trying to build the new platform for engineers to share their experience that they have earned after building and deploying stuff into production. I am trying to produce the best content possible - informative, actionable, and engaging. I'm asking for two things: hit subscribe now to show me what content you like (so I can do more of it), and if this episode helped you, pay it forward by sharing with one engineer who's facing similar challenges. That's the agreement - I deliver practical value, you help grow this resource for everyone. ♻️
Nicolay here,
most AI conversations obsess over capabilities. This one focuses on constraints - the right ones that make AI actually useful rather than just impressive demos.
Today I have the chance to talk to Dexter Horthy, who recently put out a long piece called the “12-factor agents”.
It’s like the 10 commandments, but for building agents.
One of it is “Contact human with tool calls”: the LLM can call humans for high-stakes decisions or “writes”.
The key insight is brutally simple. AI can get to 90% accuracy on most tasks - good enough for spam-like activities but disastrous for anything that requires trust. The solution isn't to wait for models to get smarter; it's to add a human approval layer for critical actions.
Imagine you are writing to a database or sending an email. Each “write” has to be approved by a human. So you post the email in a Slack channel and in most cases, your sales people will approve. In the 10%, it’s stopped in its tracks and the human can take over. You stop the slop and get good training data in the mean time.
Dexter’s company is building exactly this: an approval mechanism that lets AI agents send requests to humans before executing.
In the podcast, we also touch on a bunch of other things:
💡 Core Concepts
📶 Connect with Dexter:
📶 Connect with Nicolay:
⏱️ Important Moments
🛠️ Tools & Tech Mentioned
📚 Recommended Resources
🔮 What's Next
Next week, we will continue going more into getting generative AI into production talking to Vibhav from BAML.
💬 Join The Conversation
Follow How AI Is Built on YouTube, Bluesky, or Spotify.
If you have any suggestions for future guests, feel free to leave it in the comments or write me (Nicolay) directly on LinkedIn, X, or Bluesky. Or at [email protected].
I will be opening a Discord soon to get you guys more involved in the episodes! Stay tuned for that.
♻️ I am trying to build the new platform for engineers to share their experience that they have earned after building and deploying stuff into production. I am trying to produce the best content possible - informative, actionable, and engaging. I'm asking for two things: hit subscribe now to show me what content you like (so I can do more of it), and if this episode helped you, pay it forward by sharing with one engineer who's facing similar challenges. That's the agreement - I deliver practical value, you help grow this resource for everyone. ♻️
Today on How AI Is Built, Nicolay Gerold sits down with Jorge Arango, an expert in information architecture. Jorge emphasizes that aligning systems with users' mental models is more important than optimizing backend logic alone. He shares a clear framework with four practical steps:
Key Points:
Chapters
Information Architecture Fundamentals
What Is Information?
Mental Models vs. Data Models
Design Strategies for Complex Systems
Progressive Disclosure
Context Setting and Domain Boundaries
Conceptual Modeling (Underrated Practice)
LLMs and Information Architecture
Current and Future Applications
Implementation Advice
For Engineers and Designers
For Complex Applications
Notable Quotes:
"People only understand things relative to things they already understand." - Richard Saul Wurman
"The hardest systems to design are the ones that are meant to do a lot of things for a lot of different people." - Jorge Arango
"Very few things are intuitive. There's a long running joke in the industry that the only intuitive interface for humans is the nipple. Everything else is learned." - Jorge Arango
Jorge Arango
Nicolay Gerold:
Modern search is broken. There are too many pieces that are glued together.
Each piece works well alone.
Together, they often become a mess.
When you glue these systems together, you create:
I recently built a system where we had query specific post-filters but the requirement to deliver a fixed number of results to the user.
A lot of times, the query had to be run multiple times to achieve the desired amount.
So we had an unpredictable latency. A high load on the backend, where some queries hammered the database 10+ times. A relevance cliff, where results 1-6 look great, but the later ones were poor matches.
Today on How AI Is Built, we are talking to Marek Galovic from TopK.
We talk about how they built a new search database with modern components. "How would search work if we built it today?”
Cloud storage is cheap. Compute is fast. Memory is plentiful.
One system that handles vectors, text, and filters together - not three systems duct-taped into one.
One pass handles everything:
Vector search + Text search + Filters → Single sorted resultBuilt with hand-optimized Rust kernels for both x86 and ARM, the system scales to 100M documents with 200ms P99 latency.
The goal is to do search in 5 lines of code.
Marek Galovic:
Nicolay Gerold:
00:00 Introduction to TopK and Snowflake Comparison
00:35 Architectural Patterns and Custom Formats
01:30 Query Execution Engine Explained
02:56 Distributed Systems and Rust
04:12 Query Execution Process
06:56 Custom File Formats for Search
11:45 Handling Distributed Queries
16:28 Consistency Models and Use Cases
26:47 Exploring Database Versioning and Snapshots
27:27 Performance Benchmarks: Rust vs. C/C++
29:02 Scaling and Latency in Large Datasets
29:39 GPU Acceleration and Use Cases
31:04 Optimizing Search Relevance and Hybrid Search
34:39 Advanced Search Features and Custom Scoring
38:43 Future Directions and Research in AI
47:11 Takeaways for Building AI Applications
John Berryman moved from aerospace engineering to search, then to ML and LLMs. His path: Eventbrite search → GitHub code search → data science → GitHub Copilot. He was drawn to more math and ML throughout his career.
RAG Explained
"RAG is not a thing. RAG is two things." It breaks into:
These should be treated as separate problems to optimize.
The Little Red Riding Hood Principle
When prompting LLMs, stay on the path of what models have seen in training. Use formats, structures, and patterns they recognize from their training data:
Models respond better to familiar structures.
Testing Prompts
Testing strategies:
Managing Token Limits
When designing prompts, divide content into:
Prioritize content by:
Even with larger context windows, efficiency remains important for cost and latency.
Completion vs. Chat Models
Chat models are winning despite initial concerns about their constraints:
Applications: Workflows vs. Assistants
Two main LLM application patterns:
Breaking Down Complex Problems
Two approaches:
Example: For SOX compliance, break horizontally (understand control, find evidence, extract data, compile report) and vertically (different audit types).
On Agents
Agents exist on a spectrum from assistants to workflows, characterized by:
Best Practices
For building with LLMs:
John Berryman:
Nicolay Gerold:
00:00 Introduction to RAG: Retrieval and Generation
00:19 Optimizing Retrieval Systems
01:11 Introducing John Berryman
02:31 John's Journey from Search to Prompt Engineering
04:05 Understanding RAG: Search and Prompt Engineering
05:39 The Little Red Riding Hood Principle in Prompt Engineering
14:14 Balancing Static and Dynamic Elements in Prompts
25:52 Assistants vs. Workflows: Choosing the Right Approach
30:15 Defining Agency in AI
30:35 Spectrum of Assistance and Workflows
34:35 Breaking Down Problems Horizontally and Vertically
37:57 SOX Compliance Case Study
40:56 Integrating LLMs into Existing Applications
44:37 Favorite Tools and Missing Features
46:37 Exploring Niche Technologies in AI
52:52 Key Takeaways and Future Directions
Kuzu is an embedded graph database that implements Cypher as a library.
It can be easily integrated into various environments—from scripts and Android apps to serverless platforms.
Its design supports both ephemeral, in-memory graphs (ideal for temporary computations) and large-scale persistent graphs where traditional systems struggle with performance and scalability.
Key Architectural Decisions:
Kuzu is optimized for read-heavy, analytic workloads. While batched writes are efficient, the system is less tuned for high-frequency, small transactions. Upcoming features include:
Kuzu can be a powerful backend for AI applications in several ways:
Semih Salihoğlu:
Nicolay Gerold:
00:00 Introduction to Graph Databases
00:18 Introducing Kuzu: A Modern Graph Database
01:48 Use Cases and Applications of Kuzu
03:03 Kuzu's Research Origins and Scalability
06:18 Columnar Storage vs. Row-Oriented Storage
10:27 Query Processing Techniques in Kuzu
22:22 Compressed Sparse Row (CSR) Storage
27:25 Vectorization in Graph Databases
31:24 Optimizing Query Processors with Vectorization
33:25 Common Wisdom in Graph Databases
35:13 Introducing ASP Join in Kuzu
35:55 Factorization and Efficient Query Processing
39:49 Challenges and Solutions in Graph Databases
45:26 Write Path Optimization in Kuzu
54:10 Future Developments in Kuzu
57:51 Key Takeaways and Final Thoughts
Metadata is the foundation of any enterprise knowledge graph.
By organizing both technical and business metadata, organizations create a “brain” that supports advanced applications like AI-driven data assistants.
The goal is to achieve economies of scale—making data reusable, traceable, and ultimately more valuable.
Juan Sequeda is a leading expert in enterprise knowledge graphs and metadata management. He has spent years solving the challenges of integrating diverse data sources into coherent, accessible knowledge graphs. As Principal Scientist at data.world, Juan provides concrete strategies for improving data quality, streamlining feature extraction, and enhancing model explainability. If you want to build AI systems on a solid data foundation—one that cuts through the noise and delivers reliable, high-performance insights—you need to listen to Juan’s proven methods and real-world examples.
Terms like ontologies, taxonomies, and knowledge graphs aren’t new inventions. Ontologies and taxonomies have been studied for decades—even since ancient Greece. Google popularized “knowledge graphs” in 2012 by building on decades of semantic web research. Despite current buzz, these concepts build on established work.
Traditionally, data lives in siloed applications—each with its own relational databases, ETL processes, and dashboards. When cross-application queries and consistent definitions become painful, organizations face metadata management challenges. The first step is to integrate technical metadata (table names, columns, code lineage) into a unified knowledge graph. Then, add business metadata by mapping business glossaries and definitions to that technical layer.
A modern data catalog should:
Practical Approaches & Use Cases:
Technical Considerations:
Juan Sequeda:
Nicolay Gerold:
00:00 Introduction to Knowledge Graphs 00:45 The Role of Metadata in AI 01:06 Building Knowledge Graphs: First Steps 01:42 Interview with Juan Sequira 02:04 Understanding Buzzwords: Ontologies, Taxonomies, and More 05:05 Challenges and Solutions in Data Management 08:04 Practical Applications of Knowledge Graphs 15:38 Governance and Data Engineering 34:42 Setting the Stage for Data-Driven Problem Solving 34:58 Understanding Consumer Needs and Data Challenges 35:33 Foundations and Advanced Capabilities in Data Management 36:01 The Role of AI and Metadata in Data Maturity 37:56 The Iron Thread Approach to Problem Solving 40:12 Constructing and Utilizing Knowledge Graphs 54:38 Trends and Future Directions in Knowledge Graphs 59:17 Practical Advice for Building Knowledge Graphs
Daniel Davis is an expert on knowledge graphs. He has a background in risk assessment and complex systems—from aerospace to cybersecurity. Now he is working on “Temporal RAG” in TrustGraph.
Time is a critical—but often ignored—dimension in data. Whether it’s threat intelligence, legal contracts, or API documentation, every data point has a temporal context that affects its reliability and usefulness. To manage this, systems must track when data is created, updated, or deleted, and ideally, preserve versions over time.
Three Types of Data:
By clearly categorizing data into these buckets, systems can monitor freshness, detect staleness, and better manage dependencies between components (like code and its documentation).
Integrating Temporal Data into Knowledge Graphs:
Key Takeaways:
Daniel Davis
Nicolay Gerold:
00:00 Introduction to Temporal Dimensions in Data 00:53 Timestamping and Versioning Data 01:35 Introducing Daniel Davis and Temporal RAG 01:58 Three Buckets of Data: Observations, Assertions, and Facts 03:22 Dynamic Data and Data Freshness 05:14 Challenges in Integrating Time in Knowledge Graphs 09:41 Defining Observations, Assertions, and Facts 12:57 The Role of Time in Data Trustworthiness 46:58 Chasing White Whales in AI 47:58 The Problem with Feature Overload 48:43 Connector Maintenance Challenges 50:02 The Swiss Army Knife Analogy 51:16 API Meshes and Glue Code 54:14 The Importance of Software Infrastructure 01:00:10 The Need for Specialized Tools 01:13:25 Outro and Future Plans
Robert Caulk runs Emergent Methods, a research lab building news knowledge graphs. With a Ph.D. in computational mechanics, he spent 12 years creating open-source tools for machine learning and data analysis. His work on projects like Flowdapt (model serving) and FreqAI (adaptive modeling) has earned over 1,000 academic citations.
His team built AskNews, which he calls "the largest news knowledge graph in production." It's a system that doesn't just collect news - it understands how events, people, and places connect.
Current AI systems struggle to connect information across sources and domains. Simple vector search misses crucial relationships. But building knowledge graphs at scale brings major technical hurdles around entity extraction, relationship mapping, and query performance.
Emergent Methods built a hybrid system combining vector search and knowledge graphs:
Implementation Details:
Data Pipeline:
Entity Management:
Knowledge Graph:
System Validation:
Engineering Insights:
Key Technical Decisions:
Dead Ends Hit:
Top Quotes:
Robert Caulk:
Nicolay Gerold:
00:00 Introduction to Context Engineering 00:24 Curating Input Signals 01:01 Structuring Raw Data 03:05 Refinement and Iteration 04:08 Balancing Breadth and Precision 06:10 Interview Start 08:02 Challenges in Context Engineering 20:25 Optimizing Context for LLMs 45:44 Advanced Cypher Queries and Graphs 46:43 Enrichment Pipeline Flexibility 47:16 Combining Graph and Semantic Search 49:23 Handling Multilingual Entities 52:57 Disambiguation and Deduplication Challenges 55:37 Training Models for Diverse Domains 01:04:43 Dealing with AI-Generated Content 01:17:32 Future Developments and Final Thoughts
When you store vectors, each number takes up 32 bits.
With 1000 numbers per vector and millions of vectors, costs explode.
A simple chatbot can cost thousands per month just to store and search through vectors.
The Fix: Quantization
Think of it like image compression. JPEGs look almost as good as raw photos but take up far less space. Quantization does the same for vectors.
Today we are back continuing our series on search with Zain Hasan, a former ML engineer at Weaviate and now a Senior AI/ ML Engineer at Together. We talk about the different types of quantization, when to use them, how to use them, and their tradeoff.
Three Ways to Quantize:
Key Quotes:
Zain Hasan:
Nicolay Gerold:
vector databases, quantization, hybrid search, multi-vector support, representation learning, cost reduction, memory optimization, multimodal recommender systems, brain-computer interfaces, weather prediction models, AI applications
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