Morning.dev

DEV Community • 2026-07-27 07:17

"/usr/bin/env: 'python2': No such file or directory — Amazon Linux 2023 has no Python 2"

You moved an instance, AMI, or launch template from Amazon Linux 2 to Amazon Linux 2023, and something that used to run cleanly now fails on first boot: /usr/bin/env: 'python2': No such file or directory Or, if the script called the interpreter directly: -bash: /usr/bin/python2: No such file or directory dnf works, the instance is healthy, but any script with a #!/usr/bin/python2...

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2m read

DEV Community • 2026-07-27 07:16

31.8x Speedup by Changing One File: Async Embedding Calls on AWS Bedrock

I was testing a RAG ingestion pipeline and noticed something painful: ingesting a single document took nearly 50 seconds. Checking the metrics revealed that the CPU was doing almost nothing. The app wasn't compute-bound — it was simply sitting idle, waiting for sequential HTTP network round-trips to return. By converting the blocking embedding module into an asynchronous workflow, processing tim...

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2m read

DEV Community • 2026-07-27 07:15

Common Technical SEO Mistakes Developers Should Avoid

Most technical SEO problems aren't caused by a lack of effort — they're caused by decisions that make perfect sense from a development standpoint but quietly work against search visibility. A site can be clean, fast, and well-built, and still underperform in search because of a handful of overlooked details. Here are the mistakes that show up again and again, and why they matter more than they see...

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5m read

Hacker News • 2026-07-27 07:15

Show HN: Watch 14-Byte AI "brains" attempt to solve a 2D maze (Its hard)

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Lobsters • 2026-07-27 07:13

History of John Backus's FP languages

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1m read

𝚓𝚊𝚟𝚊𝚜𝚌𝚛𝚒𝚙𝚝 • 2026-07-27 07:11

I built OpenASCII, an open source JavaScript library for high fidelity ASCII rendering

originally built this because I needed an interactive ASCII element for another project I'm working on. But, I couldn't find anything that fit what I wanted and the ones which did, were paid to export, so i decided to build the whole thing myself. OpenASC// is a high fidelity ASCII renderer for the web with real time controls and local processing. It's built with TypeScript/js and designed to be e...

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1m read

DEV Community • 2026-07-27 07:02

From Commit to Amazon EKS: Building a GitOps Pipeline with Argo CD

Deploying an application to Kubernetes is easy to demonstrate with one command: kubectl apply -f . The harder question is what happens after the first deployment. How do you know which commit is running? How do you enforce code-quality checks? How does a new container image reach the cluster without giving the CI pipeline broad Kubernetes access? And how do you clean everything up without...

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7m read

DEV Community • 2026-07-27 07:02

Ship a Custom WordPress Endpoint Without Writing a Plugin

Your JavaScript frontend needs a list of featured products from WordPress. Not the whole REST API surface, not raw post objects with forty fields, just the ten items the homepage carousel shows, shaped the way the frontend wants them. The endpoint is ten minutes of work: query, map, return. The question that eats the rest of the afternoon: where does that code go? Where custom endpoints...

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4m read

DEV Community • 2026-07-27 07:00

My AI agent tried to delete my secrets. It couldn't.

One day, my AI agent tried to delete the secrets of my infra. It wrote the Terraform command. It ran it. Nothing happened. Not because it changed its mind. Because my Terraform only applies through the pipeline, never locally. And because it has no access to do it. That is the best moment in my whole setup. An agent did something dangerous, and it cost nothing. That is the whole idea. Don't bet...

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11m read

DEV Community • 2026-07-27 07:00

What a successful HMAC check tells you about webhook forwarding

With payment webhooks, “almost unchanged” is not unchanged enough. A real payment webhook passed through an intermediary delivery service and still verified at the final handler. Here is what that proves—and what it does not. Recently, a payment webhook in one of my production systems followed this path: Payment provider → Adal Server → Adal CLI → webhook handler The handler verified th...

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4m read

DEV Community • 2026-07-27 06:47

Rethinking the AI Agent Manual Override Queue: Enable Autonomy You Can Trust

Most teams building AI agents treat manual override queues as a last resort, a safety net for when the agent goes off the rails. That view keeps agents locked in read-only mode on anything risky. The real insight is the opposite: a well-designed AI agent manual override queue enables you to trust your agent with high-value actions you would otherwise never automate. An override queue is not a puni...

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13m read

DEV Community • 2026-07-27 06:46

Sequential Testing and the SPRT: How to Stop a Test Early Without Cheating

Sequential Testing and the SPRT: How to Stop a Test Early Without Cheating Meta description: Peeking at a fixed-sample A/B test inflates false positives. Sequential testing lets you check results repeatedly and stop early without cheating. TL;DR Fixed-sample testing assumes you'll wait for a pre-calculated sample size before looking at results. Checking early and stopping the moment ...

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11m read

DEV Community • 2026-07-27 06:46

The Confidence Tier Model: How to Decide When Your Data Isn't Enough

The Confidence Tier Model: How to Decide When Your Data Isn't Enough Meta description: Most testing programs are built for traffic they don't have. Three confidence tiers — proven, directional, speculative — each with its own bet-sizing rule. TL;DR Fixed-sample A/B testing assumes you can wait for statistical significance. Most teams can't — traffic is too thin, or the market is movi...

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8m read

DEV Community • 2026-07-27 06:46

Chain of Thought — why 'think step by step' actually works

📺 Prefer to watch? 90-second YouTube Short · 💬 Telegram Originally published on software-engineer-blog.com. You already know the trick: add "think step by step" to your prompt and the model's answer gets better. Almost nobody explains why — and the real reason has nothing to do with motivation or effort. Mental model: A transformer spends a fixed stack of layers per token, so adding reasoni...

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6m read

DEV Community • 2026-07-27 06:44

Regression Isn’t Regularization: A Simple Guide to Understanding Both

Regression and regularization are both important concepts in machine learning and statistics, but they solve different problems. Regression is primarily used to model relationships and make predictions. Regularization is used to improve a model's ability to generalize by controlling its complexity. Regression This is a statistical and machine learning technique used to predict a c...

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5m read

DEV Community • 2026-07-27 06:43

Mi stack de AI coding en 2026: Mejor calidad/precio ahorrativo y competitivo🥳️

No pago $20/mes por Copilot. No tengo un Mac. Uso Linux Mint con un agente open-source, una API que cuesta céntimos y una terminal TUI. Este es mi setup real, lo bueno y lo que no te cuentan. No es postureo. Es pragmatismo. Mira, te voy a ser sincero. Cuando empecé a usar AI para programar probé de todo: Copilot, Cursor, Codeium, Continue... y cada uno tenía algo que no me cerraba. O...

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A PDF toolkit that never uploads your files, now with batch mode

DEV Community • 2026-07-27 06:43

A PDF toolkit that never uploads your files, now with batch mode

Free Online PDF Converter – Word, HTML, Image & More Tools Free online PDF converter with complete privacy protection. Merge, split, compress, sign, and convert PDFs directly in your browser — plus a free age calculator and scientific calculator. No uploa...

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Full-stack Pokémon TCG simulator with pack opening, grading, PvP and card auctions

DEV Community • 2026-07-27 06:42

Full-stack Pokémon TCG simulator with pack opening, grading, PvP and card auctions

An ecosystem whose job is to full-fill our dream of opening and collecting pokemon cards, which we all had in our childhood. Instead of just clicking a button to reveal static images, I wanted to recreate the whole experience of getting , collecting and showing off your pokemon cards , i even added live card auctions and card shows and PSA card grading simulator to give the full-on experience whi...

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2m read

DEV Community • 2026-07-27 06:40

Migrating a Rich Text Editor : CKEditor 5 to SynapEditor (with code)

Disclosure: I work on the team behind SynapEditor. 🧩 TL;DR: Moving from CKEditor 5 to SynapEditor is a one-to-one swap in three steps: installation, toolbar config, and content/event APIs. The main reason to consider it is Office document fidelity (Word, PowerPoint, Excel import/export). Full runnable example at the end. Switching rich text editors sounds like a big job, but most of the work i...

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5m read

DEV Community • 2026-07-27 06:40

I built a guard that refused to read the user's tab. Then my own cleanup code closed it.

Three days ago my browser automation tool closed one of my own tabs. Not a tab it had opened — a dashboard I had open in another window, with a page I hadn't finished reading. What makes it worth writing up isn't the bug. It's that the guard designed to prevent exactly this had already fired, correctly, ninety seconds earlier. The guard worked Safari MCP lets an AI agent drive your re...

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6m read