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Subtitle: Build a Python app with Telnyx AI Inference that turns customer activity signals into churn risk, recommended actions, and retention next steps. Most customer churn is only surprising because the signals were scattered. Usage dropped in one place. Support tickets went up somewhere else. A renewal date got closer. A login did not happen for two weeks. Payment issues started showing up. None of those signals alone proves a customer is leaving, but together they usually tell a story. That is the workflow I wanted to make easier to build: take customer activity data, pass it through an inference model, and return a structured churn assessment that a product or customer success team can actually use. The example is here: https://github.com/team-telnyx/telnyx-code-examples/tree/main/ai-customer-churn-predictor-python It is a small Flask app using Telnyx AI Inference through the chat-completions API. The App Shape The app exposes a few routes: POST /predict for one customer POST /predict/batch for up to 20 customers GET /predictions for recent in-memory predictions GET /health for app health The current default model is set in .env.example : AI_MODEL=moonshotai/Kimi-K2.6 Under the hood, the app calls: POST https://api.telnyx.com/v2/ai/chat/completions The prompt asks the model to behave like a customer success analyst and return JSON only. That is the important part. This is not a chatbot. It is an application endpoint that produces structured output. What Goes In A request can look like this: curl -X POST http://localhost:5000/predict \ -H "Content-Type: application/json" \ -d '{ "customer_id": "CUST-123", "call_volumes": [120, 105, 80, 55], "message_volumes": [450, 420, 300, 190], "support_tickets": 6, "account_age_months": 18, "renewal_days": 21, "last_login_days": 14, "payment_issues": 1 }' Those fields are deliberately simple. The point is to show the pattern, not to pretend this is a full enterprise churn model. The model gets the trend data, support contex

Data Modeling, Relationships, and Schemas in Data Analytics In the fields of data analytics, data warehousing, and database management, modeling and schema design are the fundamental pillars used to organize and query information efficiently. This article provides a comprehensive guide to these core concepts. 1. Data Modeling Data modeling is the architectural process of designing how data is stored, interconnected, and accessed within a system. Core Questions Addressed: Storage: What specific data points need to be captured? Structure: How should individual tables be organized? Connectivity: How do these tables interact with one another? Levels of Data Models: Conceptual Model: A high-level business perspective focusing on entities and their relationships, devoid of technical specifications. Logical Model: Defines specific attributes, keys, and relationships. It is independent of the Database Management System (DBMS). Physical Model: The actual implementation within a database, including technical details like indexes, partitions, and storage requirements. 2. Relationships Relationships define the logic of how data in one table corresponds to data in another. One-to-One (1:1): A single record in Table A relates to exactly one record in Table B. One-to-Many (1:M): The most common relationship; for example, one Customer can place many Orders . Many-to-Many (M:M): Multiple records in one table relate to multiple records in another. This requires a Junction Table (Bridge Table) to function. Example: One Student can enroll in many Courses, and one Course contains many Students. 3. SQL Joins Joins are used to combine rows from two or more tables based on a related column. Join Type Description Inner Join Returns only the records that have matching values in both tables. Left Join Returns all records from the left table and the matched records from the right. Right Join Returns all records from the right table and the matched records from the left. Full Outer Join Returns

TL;DR — A Kafka + Flink + OTel ingestion pipeline cost us ~$700–800/month at 10 MB/s. We rebuilt it as a single binary where the data, the write-ahead log, and the Iceberg catalog all live in S3 alone — no Kafka, no local disks, no coordination service — for ~$100/month . Here's the design. Self-hosted observability sooner or later runs into the problem of storing state. Query load, CPU, and data volume can all be handled by scaling out, but the stateful layer is something you have to operate by hand. At first it's almost unnoticeable: a disk degrades here, replication falls behind there, a recovery hangs somewhere else. As the data grows, incidents stop being one-offs and start to recur. At some point your observability stack - whether it's Grafana Loki, Elastic, or ClickHouse - starts demanding the same attention as a full-blown database that you're on the hook for. Kubernetes operators cover some of these cases, but operating the state is still on you. Managed solutions take that burden away and bring their own: rising costs, ingestion-pipeline constraints, and limits on retention and cardinality. But if you'd rather not sign up for the constant operational grind - or live with the constraints of managed solutions - it's worth asking: can we take the stateful part out of operations entirely? Storage and format The first candidate for offloading storage responsibility is Amazon S3. S3 gives you what local disks can't: fault tolerance and practically unlimited scale, with no storage to manage yourself. It isn't free, though: data-access latency goes up, and you pick up separate costs for API operations. For OLTP workloads that's a dealbreaker. For observability workloads - which are dominated by sequential writes and analytical reads - these trade-offs are often acceptable. At first glance, this problem is already solved. Loki , for example, uses S3 as its primary storage. But according to Loki's public documentation (v3.6.x) at the time of writing, Loki doesn't re

If you have ever opened a system design article, seen a diagram with twelve boxes, three databases, a message queue, and the words "eventually consistent," and quietly closed the tab, this post is for you. There is a myth that you need years of experience running large systems before you can learn system design. You don't. Plenty of engineers learn it before they have ever deployed anything bigger than a side project. What you actually need is the right starting point and a way to build intuition without access to production-scale traffic. That is exactly what this guide gives you. "But I've never built anything at scale" Good news: neither had most people the first time they learned this. System design is not a memory test about how Uber works. It is a thinking skill: given a vague problem and some constraints, make a sequence of reasonable trade-offs and explain them clearly. That skill does not require having operated a system serving millions of users. It requires understanding what the moving parts do and practicing the reasoning. The experience helps later, but it is not the price of entry. So drop the idea that you are "not ready." You are ready to start today. The honest minimum prerequisites You do not need much, but you do need these four things. If any feels shaky, spend a few days here first; it will save you weeks of confusion later. What happens when you load a web page. Client sends a request, DNS resolves a name to an address, a server responds. If you can sketch that, you're fine. The two kinds of databases. Relational (tables, rows, SQL) versus non-relational (documents, key-value). You don't need to be an expert, just know they exist and roughly when each fits. What an index is. A way to find data fast without scanning everything. That one sentence is enough to begin. Basic estimation. If something gets a million requests a day, roughly how many is that per second? (About 12, for the record.) The ability to do rough math out loud matters more than

Overview AGENTS.md is useful. It gives AI coding agents a place to find repo-specific guidance: how to behave what conventions matter what areas need extra caution what kinds of changes should trigger review That is a meaningful improvement over sending an agent into a repo with no instructions at all. But AGENTS.md is not enough. It can tell an agent to be careful. It cannot, by itself, make execution safe, verification trustworthy, or review inspectable. For that, a repository needs more than instructions. It needs: declared safe commands a canonical verification path receipts that show what actually ran That is the difference between agent guidance and execution governance. Instructions Help. They Do Not Govern Execution. An instruction file is still prose. That means it can express intent, but it does not automatically create operational truth. For example, AGENTS.md can say: run the right checks before handoff avoid destructive commands do not edit generated files ask before touching infrastructure Those are good rules. But notice what they leave unresolved: which checks are the right ones which commands are actually safe which paths are protected structurally versus only suggested what should count as evidence that verification happened how to tell whether a failure came from code, setup, or drift That is where many agent workflows still break down. The agent may follow the spirit of the instructions and still take the wrong execution path. Safe Commands Need To Be Explicit One of the biggest gaps in agent-oriented repos is that they often declare guidance without declaring a safe command surface. The repo may tell the agent: Run tests before you finish. But that still leaves a dangerous amount of interpretation. Which task is safe? Is it: npm test pnpm test make check docker compose run test a narrower unit-test path the CI workflow itself And if several exist, which one is canonical for a routine code change? The repo should not force the agent to infer that

I've been building on DynamoDB since around 2015, and these days I build tools for it: dynoxide , a DynamoDB engine, and Nubo , a native client. So I'm not neutral about it. It's the first database I reach for, and with reason - the operational overhead is close to nil, no connections to pool or instances to size, and it holds the same single-digit-millisecond reads whether the table has a thousand items or a billion. The data modelling is a craft, and a satisfying one. It's also one of the harder databases to learn, and that's the part I keep coming back to. DynamoDB punishes the instincts you bring from SQL. You don't normalise and join at read time; you work out the questions your app will ask first, and shape the data around those access patterns, until one table answers all of them. It's a real shift in how you think, and it's where a lot of people bounce off - it feels backwards right up until it clicks. The people who teach it best all teach it the same way. Alex DeBrie's The DynamoDB Book , the arc.codes team's examples, Rick Houlihan's re:Invent talks - the legendary ones, where he models half a dozen access patterns onto a single table at a hundred miles an hour - none of them hand you rules to memorise. They show you patterns and make you run them. I learned a lot of my DynamoDB from all three, and it stuck because I was building as I went. That last part is the bit that's hard to come by on your own. Reading about an access pattern and having it in your fingers are different things, and to run one - build the table, write the items, fire the query and see what comes back - you need an AWS account, or a local emulator installed and seeded. Enough friction that plenty of people read about single-table design without ever building one. There was a second thing pulling the same way. dynoxide had learned to run in the browser only last month, compiled to WebAssembly with no server behind it, and it was a preview I didn't fully trust. What it needed was a real

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The most common failures for production agents are behavioral: looping, reasoning leakage, user frustration, and more. Using a frontier model like GPT or Sonnet to judge every turn is too expensive and slow to run at scale. To solve this, we built Reflexes: semantic signals from agent traces, served fast and cheap over API. Built on custom kernels and a custom inference engine forked from vLLM. Under the hood, it is a small LLM architected around multi-head inference. Small models need to be tra

"That would be an awesome capability."