标签：#ev

You've deployed your app to Kubernetes. The pod starts — then it gets killed. Or it's running but no traffic reaches it. Or it takes 90 seconds to initialize and gets restarted in a loop. Every one of these problems traces back to the same root cause: misconfigured or missing health probes . Kubernetes gives you three types of probes: livenessProbe , readinessProbe , and startupProbe . Each serves a different purpose. Mix them up and your pods restart in infinite loops. Get them right and your deployments self-heal, scale correctly, and handle rolling updates without a single dropped request. Here's what each probe does, when to use it, and how to configure it for a real production service. 1. Liveness Probe: Is the Container Alive? The liveness probe answers one question: "Is this container still running correctly?" If the probe fails, kubelet kills the container and restarts it. livenessProbe: httpGet: path: /healthz port: 8080 initialDelaySeconds: 5 periodSeconds: 10 failureThreshold: 3 Use liveness probes for deadlock detection . If your app enters a state where it's alive but not making progress (a goroutine leak, a stuck mutex, an infinite loop), the liveness probe exposes that and triggers a restart. The #1 mistake people make: using the liveness probe to check external dependencies like databases or upstream APIs. Don't do this. If your database is down and your liveness probe fails, Kubernetes will restart your pod — but the database is still down. Restarting the app doesn't help, and now you have a crash loop on top of a DB outage. That's worse. Liveness probes should only check internal process health. Not database connectivity, not Redis, not upstream services. 2. Readiness Probe: Is the Container Ready for Traffic? The readiness probe answers: "Should this pod receive traffic?" If it fails, the pod is removed from all Service endpoints. It is not restarted. readinessProbe: httpGet: path: /ready port: 8080 periodSeconds: 5 failureThreshold: 2 successThre

A previous post covered how to absorb PHP 8.2 Deprecated warnings from WP-CLI using a three-layer defense . The approach — prepending WP_CLI_PHP_ARGS to set error_reporting — works in many environments. But a case came up where Deprecated warnings wouldn’t disappear despite the same configuration. Tracing the cause revealed a structural reason why the environment variable never arrived. This post records that root cause and the three-part fix added in v1.6.8. Why environment variables don’t arrive — the phar + shebang execution path An agency reported that on Xserver, plugin list retrieval was failing across multiple sites (referred to here as "site A / site B") with a large volume of Deprecated messages. We reproduced the same behavior on our own Xserver setup (PHP 8.2.30, WP-CLI 2.7.1) and traced the execution path. Xserver’s /usr/bin/wp is a phar binary. Inside, it starts with a #!/usr/bin/env php shebang, so the actual startup sequence looks like this: shell → /usr/bin/wp (shebang: #!/usr/bin/env php) ↓ env locates php and starts it ↓ php loads the phar → WP-CLI runs In this path, WP_CLI_PHP_ARGS is never read as a PHP startup option. WP_CLI_PHP_ARGS is supposed to let WP-CLI pass a -d flag to PHP, but when PHP itself is launched via shebang, control never reaches the point where WP-CLI can inject that flag into PHP’s invocation. # doesn’t work — /usr/bin/wp on Xserver is a shebang-launched phar WP_CLI_PHP_ARGS = "-d error_reporting='E_ALL & ~E_DEPRECATED'" wp plugin list --format = json # works — -d goes directly to the php binary php -d error_reporting = 'E_ALL & ~E_DEPRECATED & ~E_USER_DEPRECATED' /tmp/wp-cli-2.7.1.phar plugin list --format = json We verified this against our production setup: with the first form, 407 Deprecated lines remained; with the second, 0. Pillar A — detecting the php-direct path and injecting -d The fix: inspect wp_cli_path for whether it’s a php-direct invocation, and if so, inject -d error_reporting immediately after the PHP

This is a submission for DEV's Summer Bug Smash: Smash Stories powered by Sentry . This is our official submission for the DEV Big Summer Bug Smash challenge under the #bugsmash track. Below is the technical tale of how we isolated, debugged, and optimized cross-layer node latency issues when deploying our Web3 framework on Polygon. The Problem: The Post-Hard Fork RPC Latency Wall 🐛 During heavy network volume spikes or directly following major ledger upgrades, our automated event listener logging pipeline kept crashing with random, non-deterministic invalid block range exceptions when attempting to pull historical data blocks via standard eth_getLogs routines. The Technical Root Cause The root bottleneck came down to an internal desync inside shared public RPC telemetry environments: The Bor Layer mints new block headers at a blistering speed (~2 seconds). The Internal Indexer DB takes slightly longer to completely unpack, parse, and commit transaction event logs to disk. When our asynchronous scripts called the node, latest grabbed the bleeding edge tip of the chain from memory, but a simultaneous getLogs query hit the slower indexer database. This split-millisecond race condition threw immediate pipeline errors. The Fix: Layered Application Buffering 🛠️ To smash this bug without modifying low-level node client builds, we engineered a programmatic block-padding delay loop directly into our interaction routers. Instead of tracking unfinalized tip block states blindly, we forced our queries to target safe block ranges sitting securely just behind the tip of the chain. // Localized block-buffer deployment fix const currentChainTip = await provider . getBlockNumber (); const indexedBlockBoundary = currentChainTip - 3 ; // Buffer 3 blocks (~6 second safety zone) const targetLogs = await contract . getLogs ({ fromBlock : indexedBlockBoundary - 20 , toBlock : indexedBlockBoundary }); This structural adjustment completely stabilized our off-chain reward data pipeline, gua

Optimizing RAG at Scale: Chunking, Retrieval, and the Bayesian Search That Cut Latency 40% How we moved from "semantic search + hope" to a measured, tunable retrieval pipeline with 95% recall@10 The RAG Reality Check Everyone ships RAG the same way: chunk by 512 tokens, embed with text-embedding-3-small , top-k=5, stuff into context. It works for demos. Then you hit production: Legal contracts: 512 tokens splits clauses mid-sentence API docs: 1000-token chunks drown signal in noise Customer tickets: Conversational context needs overlap, not fixed windows Latency: 500ms embedding + 200ms vector search + 300ms LLM = 1s+ per query We rebuilt our retrieval layer from first principles. Here's what actually moves metrics. Chunking: One Size Fits None # rag/chunking.py from abc import ABC , abstractmethod from dataclasses import dataclass @dataclass class Chunk : text : str metadata : dict token_count : int chunk_id : str class ChunkingStrategy ( ABC ): @abstractmethod def chunk ( self , document : str , metadata : dict ) -> list [ Chunk ]: ... class FixedTokenChunker ( ChunkingStrategy ): """ Baseline. Good for homogeneous content. """ def __init__ ( self , chunk_size = 512 , overlap = 50 ): self . chunk_size = chunk_size self . overlap = overlap class RecursiveChunker ( ChunkingStrategy ): """ Respects structure: markdown headers, code blocks, paragraphs. """ def __init__ ( self , separators = [ " \n ## " , " \n ### " , " \n\n " , " \n " , " " ], chunk_size = 512 ): self . separators = separators self . chunk_size = chunk_size class SemanticChunker ( ChunkingStrategy ): """ Uses embedding similarity to find natural boundaries. """ def __init__ ( self , model = " text-embedding-3-small " , threshold = 0.7 ): self . model = model self . threshold = threshold class AgenticChunker ( ChunkingStrategy ): """ LLM decides boundaries. Expensive but highest quality for complex docs. """ def __init__ ( self , model = " gpt-4o-mini " ): self . model = model Our production config by

Building Production-Grade LLM Evaluation Pipelines: From Vibes to Metrics How we replaced "looks good to me" with automated evaluation catching 92% of hallucinations before deployment The Problem: Why "Vibe Checks" Fail in Production Three months ago, our team shipped a RAG-based customer support assistant. It worked great in testing — we'd ask it questions, read the answers, and say "yeah, that looks right." Then it hit production. A customer asked about their billing cycle. The assistant confidently cited a policy that didn't exist. Another asked about API rate limits and got numbers from a competitor's documentation. By the time we caught it, 500+ users had seen hallucinated responses. The post-mortem was brutal: we had zero automated evaluation . Our test process was literally "ask 5 questions, read answers, thumbs up." What Production Evaluation Actually Needs Academic benchmarks (MMLU, HellaSwag) don't tell you if your system works for your use case. Production evaluation needs: Domain-specific judges — Your criteria, not generic "helpfulness" Speed — Evaluation must run in CI/CD, not overnight Regression detection — Know immediately when a prompt change breaks things CI/CD integration — Block merges that degrade quality Golden dataset management — Versioned, stratified, growing test cases Architecture: The Evaluation Pipeline ┌─────────────┐ ┌──────────────┐ ┌────────────────────┐ ┌──────────────┐ │ Test Cases │────▶│ LLM Under │────▶│ Judge Ensemble │────▶│ Metrics & │ │ (Golden Set)│ │ Test │ │ - Faithfulness │ │ Regression │ └─────────────┘ └──────────────┘ │ - Instruction F. │ │ Detection │ │ - JSON Schema │ └──────┬───────┘ │ - Custom LLM │ ▼ └────────────────────┘ ┌──────────────┐ │ Dashboard/ │ │ PR Comments │ └──────────────┘ Core Abstractions # eval/base.py @dataclass ( frozen = True ) class TestCase : id : str input : dict [ str , Any ] expected : dict [ str , Any ] | None = None tags : list [ str ] = field ( default_factory = list ) # ["edge-case",

Most "SSG vs SSR vs ISR" content out there is written from documentation. Someone reads the framework, restates it, and you're left inferring the actual difference in performance and behavior. So I built a lab where you can just run the commands and see it yourself, no table to trust blindly. astro-wp-seo-lab builds the same WordPress content four different ways with Astro 7.1.1, then serves all four side by side so you can compare them directly. git clone https://github.com/nimajafari/astro-wp-seo-lab npm install npm run compare That builds each arm into its own directory and serves them all at once. arm url what it is ssg-full http://localhost:4301 everything prerendered at build time ssr http://localhost:4302 rendered per request, no caching ssr-cdn http://localhost:4303 per request plus CDN cache headers route-cache http://localhost:4304 per request plus Astro 7 route caching islands http://localhost:4305 static shell with deferred fragments Every page has a black bar at the top showing which arm rendered it and when. That timestamp is the instrument for most of what follows. First build takes a few minutes since each arm fetches from WordPress, later builds are faster because the Content Layer loader caches between them. It ships pointed at a live WordPress install (oxyplug.com), but it works against any public WordPress site with the REST API exposed. npm run probe -- https://your-site.com --save mysite SOURCE = mysite npm run compare probe checks what your own install actually exposes, REST API reachability, Yoast presence, permalink structure, then saves it under a name. Use the URLs npm run compare prints for your own site instead of the ones below, since those are generated from your own content. Build time vs request time This is the distinction most of the SSG vs SSR debate hinges on, and it takes about 30 seconds to see for yourself. Open these two side by side and reload each a few times. http://localhost:4301/optimization/crl-ocsp-certificate-revocati

Optimizing RAG at Scale: Chunking, Retrieval, and the Bayesian Search That Cut Latency 40% How we moved from "semantic search + hope" to a measured, tunable retrieval pipeline with 95% recall@10 The RAG Reality Check Everyone ships RAG the same way: chunk by 512 tokens, embed with text-embedding-3-small , top-k=5, stuff into context. It works for demos. Then you hit production: Legal contracts: 512 tokens splits clauses mid-sentence API docs: 1000-token chunks drown signal in noise Customer tickets: Conversational context needs overlap, not fixed windows Latency: 500ms embedding + 200ms vector search + 300ms LLM = 1s+ per query We rebuilt our retrieval layer from first principles. Here's what actually moves metrics. Chunking: One Size Fits None # rag/chunking.py from abc import ABC , abstractmethod from dataclasses import dataclass @dataclass class Chunk : text : str metadata : dict token_count : int chunk_id : str class ChunkingStrategy ( ABC ): @abstractmethod def chunk ( self , document : str , metadata : dict ) -> list [ Chunk ]: ... class FixedTokenChunker ( ChunkingStrategy ): """ Baseline. Good for homogeneous content. """ def __init__ ( self , chunk_size = 512 , overlap = 50 ): self . chunk_size = chunk_size self . overlap = overlap class RecursiveChunker ( ChunkingStrategy ): """ Respects structure: markdown headers, code blocks, paragraphs. """ def __init__ ( self , separators = [ " \n ## " , " \n ### " , " \n\n " , " \n " , " " ], chunk_size = 512 ): self . separators = separators self . chunk_size = chunk_size class SemanticChunker ( ChunkingStrategy ): """ Uses embedding similarity to find natural boundaries. """ def __init__ ( self , model = " text-embedding-3-small " , threshold = 0.7 ): self . model = model self . threshold = threshold class AgenticChunker ( ChunkingStrategy ): """ LLM decides boundaries. Expensive but highest quality for complex docs. """ def __init__ ( self , model = " gpt-4o-mini " ): self . model = model Our production config by

Over the past few years, AI has fundamentally changed how software gets built. Teams can go from an idea to a working application in a fraction of the time it used to take, and founders can create products with resources that would have been unimaginable just a few years ago. That's an incredible shift, and I think it's one of the most exciting changes our industry has seen. What hasn't changed, though, is the question that comes after the application is built: Is it actually ready? Throughout my career, I've been involved in delivering enterprise software across many different industries and organizations. One thing I've learned is that there isn't a single definition of what makes an application "ready." If you ask six different stakeholders whether a system is ready, you'll probably get six different answers—and they're all likely to be valid. That's because each person is looking at the software through the lens of the outcome they're responsible for: A founder may be wondering whether the application can handle the growth they're hoping for over the next year. A CTO is often focused on where the biggest technical risks are and what should be improved first. An engineering leader is thinking about production readiness, security, reliability, and operational support. An agency inheriting a client application wants to understand what they're taking ownership of before making commitments. An acquirer is trying to estimate the cost of technical debt An Investor wants confidence that the technology is creating long-term value rather than future expense. Those perspectives are different because the questions they're trying to answer are different. The challenge is that we often evaluate all software the same way. Traditional assessments tend to focus on the health of the codebase. They look at architecture, security, maintainability, testing, complexity, and technical debt. Those are all important, and they should absolutely be part of any technical review. But they'r

Early Access games create a documentation problem that ordinary wikis do not handle well: the facts can change faster than search results, community posts, and copied tables are updated. A page can look polished and still be wrong for the current build. I have been working on an independent Subnautica 2 player wiki, and the most useful engineering lesson has been to treat every guide, map marker, and item row as versioned data rather than timeless prose. This post describes the workflow without assuming any particular framework. 1. Put provenance next to the fact For every structured record, keep at least: the game build or patch it was checked against; the source type: official note, in-game observation, or community report; the observation date; a confidence state such as verified, provisional, or disputed; a stable identifier that survives display-name changes. A user should not have to trust a page because it looks complete. They should be able to see whether a coordinate came from the current build and whether another player can reproduce it. 2. Separate stable identity from mutable labels Names, descriptions, recipes, and locations may change. Use an internal key as the identity and keep display text as versioned attributes. This prevents an item rename from creating a second logical entity or breaking every inbound link. The same rule helps with localization: English and translated labels point to one entity, while the source and verification state remain shared. 3. Model maps as evidence, not decoration An interactive map should not be a pile of pins. A useful marker contains coordinates, category, build, evidence, verification state, and a short player-facing note. If a patch moves or removes the object, preserve the history and mark the old observation as superseded. This also makes filters honest. “Show verified markers for the current build” is a meaningful query; “show everything ever imported” is not. 4. Make guides depend on structured facts Low-spoil

Optimizing RAG at Scale: Chunking, Retrieval, and the Bayesian Search That Cut Latency 40% How we moved from "semantic search + hope" to a measured, tunable retrieval pipeline with 95% recall@10 The RAG Reality Check Everyone ships RAG the same way: chunk by 512 tokens, embed with text-embedding-3-small , top-k=5, stuff into context. It works for demos. Then you hit production: Legal contracts: 512 tokens splits clauses mid-sentence API docs: 1000-token chunks drown signal in noise Customer tickets: Conversational context needs overlap, not fixed windows Latency: 500ms embedding + 200ms vector search + 300ms LLM = 1s+ per query We rebuilt our retrieval layer from first principles. Here's what actually moves metrics. Chunking: One Size Fits None # rag/chunking.py from abc import ABC , abstractmethod from dataclasses import dataclass @dataclass class Chunk : text : str metadata : dict token_count : int chunk_id : str class ChunkingStrategy ( ABC ): @abstractmethod def chunk ( self , document : str , metadata : dict ) -> list [ Chunk ]: ... class FixedTokenChunker ( ChunkingStrategy ): """ Baseline. Good for homogeneous content. """ def __init__ ( self , chunk_size = 512 , overlap = 50 ): self . chunk_size = chunk_size self . overlap = overlap class RecursiveChunker ( ChunkingStrategy ): """ Respects structure: markdown headers, code blocks, paragraphs. """ def __init__ ( self , separators = [ " \n ## " , " \n ### " , " \n\n " , " \n " , " " ], chunk_size = 512 ): self . separators = separators self . chunk_size = chunk_size class SemanticChunker ( ChunkingStrategy ): """ Uses embedding similarity to find natural boundaries. """ def __init__ ( self , model = " text-embedding-3-small " , threshold = 0.7 ): self . model = model self . threshold = threshold class AgenticChunker ( ChunkingStrategy ): """ LLM decides boundaries. Expensive but highest quality for complex docs. """ def __init__ ( self , model = " gpt-4o-mini " ): self . model = model Our production config by

Building Production-Grade LLM Evaluation Pipelines: From Vibes to Metrics How we replaced "looks good to me" with automated evaluation catching 92% of hallucinations before deployment The Problem: Why "Vibe Checks" Fail in Production Three months ago, our team shipped a RAG-based customer support assistant. It worked great in testing — we'd ask it questions, read the answers, and say "yeah, that looks right." Then it hit production. A customer asked about their billing cycle. The assistant confidently cited a policy that didn't exist. Another asked about API rate limits and got numbers from a competitor's documentation. By the time we caught it, 500+ users had seen hallucinated responses. The post-mortem was brutal: we had zero automated evaluation . Our test process was literally "ask 5 questions, read answers, thumbs up." What Production Evaluation Actually Needs Academic benchmarks (MMLU, HellaSwag) don't tell you if your system works for your use case. Production evaluation needs: Domain-specific judges — Your criteria, not generic "helpfulness" Speed — Evaluation must run in CI/CD, not overnight Regression detection — Know immediately when a prompt change breaks things CI/CD integration — Block merges that degrade quality Golden dataset management — Versioned, stratified, growing test cases Architecture: The Evaluation Pipeline ┌─────────────┐ ┌──────────────┐ ┌────────────────────┐ ┌──────────────┐ │ Test Cases │────▶│ LLM Under │────▶│ Judge Ensemble │────▶│ Metrics & │ │ (Golden Set)│ │ Test │ │ - Faithfulness │ │ Regression │ └─────────────┘ └──────────────┘ │ - Instruction F. │ │ Detection │ │ - JSON Schema │ └──────┬───────┘ │ - Custom LLM │ ▼ └────────────────────┘ ┌──────────────┐ │ Dashboard/ │ │ PR Comments │ └──────────────┘ Core Abstractions # eval/base.py @dataclass ( frozen = True ) class TestCase : id : str input : dict [ str , Any ] expected : dict [ str , Any ] | None = None tags : list [ str ] = field ( default_factory = list ) # ["edge-case",

Introducing vernLLM: A Resilience Layer for LLM Applications Building production-ready LLM applications is not just about sending prompts and receiving responses. Real-world AI systems need to handle timeouts, provider failures, rate limits, inconsistent outputs, and reliability issues. That is where vernLLM comes in. vernLLM is a lightweight resilience layer for OpenAI-compatible chat completion APIs , providing a single interface with built-in retries, timeouts, circuit breaking, caching, structured output, and usage tracking. Instead of rebuilding the same reliability features for every LLM project, vernLLM gives you the tools needed to make your AI integrations more robust from the start. Features Automatic retries with backoff Transient failures happen. vernLLM automatically retries recoverable errors while failing fast on validation errors and non-retryable responses. Timeouts & cancellation Prevent hanging requests with configurable timeouts and cancellation support. Circuit breaker protection Automatically stop sending requests to failing providers and recover when the service becomes healthy again. Structured output with type safety Pass a Zod schema and receive validated, typed results back. const result = await llm . call ({ systemPrompt : ' Return JSON: { "skills": string[] } ' , userContent : ' Extract skills from: ... ' , schema : SkillsSchema // zod schema }); Provider-native JSON Schema support Constrain model generation itself instead of only validating responses afterward. Built-in caching support Cache LLM responses using your own cache adapter with cachedCall and cachedLLMCall . One interface across providers Use the same API across multiple providers: OpenAI Groq Mistral DeepSeek Cerebras Together AI Fireworks AI Ollama Anthropic Gemini AWS Bedrock Any HTTP-compatible provider through fromFetch Why vernLLM? Many LLM applications end up creating their own wrappers around provider SDKs to handle: retry logic API failures provider switching respons

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You probably know the signature PlayStation boot sound. Did you know that it's technically a multi-part chime? There's the synthy section where "Sony Computer Entertainment" shows onscreen with a white background. You only get to the next screen with the echo-y chimes and the color-filled PlayStation logo if your console recognizes the disc. How badly […]

Microsoft PowerToys includes a Hosts File Editor. It is free, signed, and already on many Windows machines. It is a good editor. It is not always a good hosts workflow . What PowerToys Hosts does well Opens the real Windows hosts file with the right elevation story Simpler than hunting C:\Windows\System32\drivers\etc\hosts in Notepad Free if you already use PowerToys Fine for a handful of static lines When people search for an alternative You switch environments all day Local shop in the morning, client staging after lunch, cutover IP at night. An editor with one big file turns into commented chaos. You want named profiles you can toggle, not archaeology in comments. You also use a Mac or Linux box PowerToys is Windows-only. Your hosts process should not fork by OS if the team shares domain names. You forget ipconfig /flushdns Same bug as every other hosts tool without auto flush: file correct, browser wrong. Alternatives on Windows SwitchHosts Free, open source, profiles, also runs on Mac/Linux. Best PowerToys alternative when you need environment switching and maybe multi-OS later. Locahl Paid one-time. Windows, macOS, Linux. Automatic DNS flush and backups. Best when PowerToys feels too manual and you want the apply step to include flush + safety. Notepad as Administrator Still works. Still easy to save the wrong copy or skip flush. Only fine for rare edits. Hostly / CLI hosts switchers Interesting if you want hosts open Dev from scripts. Check that the project is maintained before you depend on it in CI. Feature snapshot (Windows view) Tool Profiles Auto flush Multi-OS Cost PowerToys Hosts Limited No No Free SwitchHosts Yes No Yes Free Locahl Yes Yes Yes One-time Notepad Admin No No Manual Free Practical upgrade path Keep PowerToys for now if you only have 5 stable lines When you start commenting / staging blocks every week, move to SwitchHosts or Locahl Always backup before the first import After every apply: ipconfig /flushdns ping myapp .test If PowerToys is

Every distributor we spoke to has the same quiet bottleneck, and none of them call it a problem. They call it Tuesday. A request for quote lands in a shared inbox. Sometimes it is a tidy bulleted list. More often it is three lines of text from someone's phone, or a PDF that was scanned at an angle. Someone on the sales desk reads it, works out which catalog part each line actually refers to, checks pricing, and types up a quote. A busy desk does this thirty or forty times a day. It is slow, it is boring, and it is exactly the kind of work where a tired person on a Friday afternoon quotes the wrong bolt and nobody notices until the shipment arrives. We spent three weeks building Distill.ai to do that job. This is what we learned, including the parts that went badly. What we actually built You paste an email or upload a PDF. From there a seven stage pipeline runs: parse -> extract -> classify -> match -> price -> policy -> score Parse cleans the document into text. Extract pulls out the individual line items, quantities, and specs. Classify works out what kind of request this is. Match maps each line to a real catalog SKU. Price applies the pricing rules. Policy runs the business checks. Score attaches a confidence value to every match. The interesting part is not the happy path. It is what happens when the model is unsure. Any line that scores below a 0.70 match threshold does not get quoted. It gets flagged with a reason and routed to a human review queue. A person confirms or corrects it, and the quote goes out clean. That one decision is the difference between a demo and something a sales desk would actually put its name on. An agent that is confidently wrong 5% of the time is worse than useless in procurement, because someone has to check all 100% of the output anyway. An agent that says "I got 47 of these 50 lines, here are the 3 I could not resolve" saves real hours. Why Qwen, and how we wired it up We used two models from Alibaba Cloud Model Studio: Qwen-Plus

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Optimizing RAG at Scale: Chunking, Retrieval, and the Bayesian Search That Cut Latency 40% How we moved from "semantic search + hope" to a measured, tunable retrieval pipeline with 95% recall@10 The RAG Reality Check Everyone ships RAG the same way: chunk by 512 tokens, embed with text-embedding-3-small , top-k=5, stuff into context. It works for demos. Then you hit production: Legal contracts: 512 tokens splits clauses mid-sentence API docs: 1000-token chunks drown signal in noise Customer tickets: Conversational context needs overlap, not fixed windows Latency: 500ms embedding + 200ms vector search + 300ms LLM = 1s+ per query We rebuilt our retrieval layer from first principles. Here's what actually moves metrics. Chunking: One Size Fits None # rag/chunking.py from abc import ABC , abstractmethod from dataclasses import dataclass @dataclass class Chunk : text : str metadata : dict token_count : int chunk_id : str class ChunkingStrategy ( ABC ): @abstractmethod def chunk ( self , document : str , metadata : dict ) -> list [ Chunk ]: ... class FixedTokenChunker ( ChunkingStrategy ): """ Baseline. Good for homogeneous content. """ def __init__ ( self , chunk_size = 512 , overlap = 50 ): self . chunk_size = chunk_size self . overlap = overlap class RecursiveChunker ( ChunkingStrategy ): """ Respects structure: markdown headers, code blocks, paragraphs. """ def __init__ ( self , separators = [ " \n ## " , " \n ### " , " \n\n " , " \n " , " " ], chunk_size = 512 ): self . separators = separators self . chunk_size = chunk_size class SemanticChunker ( ChunkingStrategy ): """ Uses embedding similarity to find natural boundaries. """ def __init__ ( self , model = " text-embedding-3-small " , threshold = 0.7 ): self . model = model self . threshold = threshold class AgenticChunker ( ChunkingStrategy ): """ LLM decides boundaries. Expensive but highest quality for complex docs. """ def __init__ ( self , model = " gpt-4o-mini " ): self . model = model Our production config by

Building Production-Grade LLM Evaluation Pipelines: From Vibes to Metrics How we replaced "looks good to me" with automated evaluation catching 92% of hallucinations before deployment The Problem: Why "Vibe Checks" Fail in Production Three months ago, our team shipped a RAG-based customer support assistant. It worked great in testing — we'd ask it questions, read the answers, and say "yeah, that looks right." Then it hit production. A customer asked about their billing cycle. The assistant confidently cited a policy that didn't exist. Another asked about API rate limits and got numbers from a competitor's documentation. By the time we caught it, 500+ users had seen hallucinated responses. The post-mortem was brutal: we had zero automated evaluation . Our test process was literally "ask 5 questions, read answers, thumbs up." What Production Evaluation Actually Needs Academic benchmarks (MMLU, HellaSwag) don't tell you if your system works for your use case. Production evaluation needs: Domain-specific judges — Your criteria, not generic "helpfulness" Speed — Evaluation must run in CI/CD, not overnight Regression detection — Know immediately when a prompt change breaks things CI/CD integration — Block merges that degrade quality Golden dataset management — Versioned, stratified, growing test cases Architecture: The Evaluation Pipeline ┌─────────────┐ ┌──────────────┐ ┌────────────────────┐ ┌──────────────┐ │ Test Cases │────▶│ LLM Under │────▶│ Judge Ensemble │────▶│ Metrics & │ │ (Golden Set)│ │ Test │ │ - Faithfulness │ │ Regression │ └─────────────┘ └──────────────┘ │ - Instruction F. │ │ Detection │ │ - JSON Schema │ └──────┬───────┘ │ - Custom LLM │ ▼ └────────────────────┘ ┌──────────────┐ │ Dashboard/ │ │ PR Comments │ └──────────────┘ Core Abstractions # eval/base.py @dataclass ( frozen = True ) class TestCase : id : str input : dict [ str , Any ] expected : dict [ str , Any ] | None = None tags : list [ str ] = field ( default_factory = list ) # ["edge-case",

This is a submission for DEV's Summer Bug Smash: Smash Stories powered by Sentry . I spent a week deploying a CrewAI agent to AWS Bedrock AgentCore. The SDK wasn't on PyPI. The error messages were 200 OKs. The container crashed without logs. And the naming regex rejected hyphens without telling me why. This is the full debugging trail. Every failure was silent. Every fix required reading source code nobody documented. Table of Contents The Project Failure 1: The SDK That Doesn't Exist on PyPI Failure 2: The 200 OK That Means Failure Failure 3: The Container That Crashed With No Logs Failure 4: The Naming Regex Nobody Documented The Two-Client Split Nobody Mentions What I Learned The project I built a resume-tailoring AI agent with CrewAI and Amazon Bedrock. It takes a job description, analyzes your resume, identifies gaps, and rewrites bullet points to match what the role actually needs. Locally it worked perfectly. CrewAI orchestrates the agents, Bedrock Nova Pro handles the LLM calls, and the output is solid. Deploying it to production was the problem. AWS launched Bedrock AgentCore in June 2026 as a managed runtime for AI agents. You containerize your agent, push the image, and AgentCore handles scaling, memory, and invocation. Sounds simple. It was not simple. Failure 1: The SDK that doesn't exist on PyPI The docs say to install bedrock-agentcore-client . I ran: pip install bedrock-agentcore-client It installed successfully. No errors. That's because there's a placeholder package on PyPI with that name. It installs, imports fail silently, and your container builds successfully with a broken dependency inside. The real SDK lives in AWS's CodeArtifact registry. You need to configure pip to pull from a private index: aws codeartifact login --tool pip \ --domain amazon-agent-runtimes \ --repository agent-runtimes-pypi \ --domain-owner 600427722194 Then install from there. The PyPI package is a trap. Nobody warns you. Hours lost: 3. The error only appears at runtime