I Failed a Python Interview Because I Could Write Code But Not Read It
I want to tell you about the most embarrassing 45 minutes of my developer career. I had been practicing LeetCode for three months. Easy problems, done…
Testing & QA
⚑ Report a ProblemLatest Testing & QA news from Tech News
All topics
agents
ai
api
architecture
automation
aws
beginners
career
claude
cybersecurity
database
devchallenge
devops
discuss
javascript
llm
machinelearning
mcp
opensource
performance
productivity
programming
python
security
showdev
softwareengineering
testing
tutorial
typescript
webdev
Ollama Structured Outputs in Practice — Getting Type-Safe JSON from Local LLMs with Pydantic
json.loads(response) fails at a certain point. You told the model "return JSON only," but it added a ```json markdown code fence around everything. A …
From ML Tooling to Analytical Governance: Recent Updates to KMDS
Over the last few months I've been refining KMDS, a framework for building repeatable and auditable machine learning systems. The original motivation …
Web-Based Security Assessment Platform Using Python, Flask & Open-Source Security Tools
A centralized web-based security assessment platform built with Python and Flask that integrates Nmap, Nikto, WhatWeb, Gobuster, and OWASP ZAP for aut…
Python interview questions: what each one actually predicts on the job (2026)
Canonical: this is a cross-post. The original lives at https://four-leaf.ai/blog/python-interview-questions You can find a hundred Python interview qu…
Cloud Architect's 2026 Guide to Cheaper, Faster LLM Inference
Cloud Architect's 2026 Guide to Cheaper, Faster LLM Inference Three months ago I opened our quarterly cloud spend dashboard and almost choked on my co…
Engineering CellFateBench: A Reproducible Python Benchmark for Single-Cell Genomics Reasoning
CellFateBench is a scientific software and benchmark-engineering project for evaluating reasoning over single-cell genomics workflows. The project was…
Cutting My AI Bill by 60%: A Freelancer's Context Window Diary
Cutting My AI Bill by 60%: A Freelancer's Context Window Diary Look, I'll be honest with you. Six months ago I was hemorrhaging money on API calls. No…
How I Cut AI API Costs by 65% — A Freelance Dev's 2026 Guide
How I Cut AI API Costs by 65% — A Freelance Dev's 2026 Guide Three months ago I opened my monthly invoice from a client project and nearly choked on m…
The HTTP Code Your AI Agent Doesn't Handle Yet: 402
Your fetch agent knows two endings to a request. 200 : parse it. 403 : back off, rotate, or skip. That branch has been the whole game for years. There…
Expanding the Sovereign AI Stack: Moving the Specification from Gateway to Local Silicon
When I first introduced the Sovereign Systems Specification and released the initial foundation of the SDK, sovereign-core and its accompanying sovere…
Reduce LLM Token Waste in RAG with Markdown
TL;DR Feeding raw HTML to Large Language Models wastes tokens on markup, scripts, and styling. By rendering dynamic web pages in a headless browser an…
Fast Automatic ML Hyperparameter tuning Using Optuna (w. MLflow model registry and IRIS DB)
This article presents a straightforward approach to automatically and efficiently tune hyperparameters for machine learning models using Optuna as the…
Building an Instagram-powered app without managing scraping infrastructure
When I started building , I needed reliable access to Instagram data. Like many developers, my first instinct was to use a self-hosted solution such a…
Discovering PII Inside InterSystems IRIS
Data privacy regulations such as GDPR, LGPD, and HIPAA demand that organizations know exactly where Personally Identifiable Information (PII) lives in…
How I Architected a 99.9% Uptime RAG Stack with DeepSeek — 2026 Guide
How I Architected a 99.9% Uptime RAG Stack with DeepSeek — 2026 Guide I lost sleep over a single p99 spike last March. Our retrieval-augmented generat…
I Wish I Knew AI Recommendation Sooner — Here's the Full Breakdown
So here's what happened: i Wish I Knew AI Recommendation Sooner — Here's the Full Breakdown Last quarter I burned through about three billable hours d…
I Built a Mini Message Broker in Pure Python and Finally Understood How Kafka Moves Millions of Events
Last year I was on a team that pushed 40 million events per day through Kafka. We had consumer lag alerts, rebalancing incidents, and a whole runbook …
I spent weeks scraping 50 websites—here's what finally worked
A few months ago, I needed to build a price comparison tool. The data lived across 50 different e‑commerce sites, each with its own layout, anti‑bot m…
I Built a Self-Hosted Competitor Price Monitor Because SaaS Pricing Is Out of Control
I Built a Self-Hosted Competitor Price Monitor Because SaaS Pricing Is Out of Control The Problem I run a small online store. To stay competitive, I n…
Status updates that write themselves from your git activity
I've typed the same status update hundreds of times. "Worked on the auth refactor, still going on it, no blockers." Then I'd open the PR I'd literally…
Signing your random numbers is theater. Here's what actually makes randomness trustworthy.
Three of my autonomous agents needed to pick a leader. Each one called random.random() , highest number wins. All three reported they won. Obviously. …
Stop Shipping ML Models With Bare Floats: A Deep Dive Into Statistically Rigorous Model Evaluation
Stop Shipping ML Models With Bare Floats Every week, somewhere, a team makes a deployment decision that looks like this: Model A: AUROC = 0.847 Model …
How I debug RAG failures with deterministic signals
When building LLM apps, one frustrating problem is that a response can be wrong for many different reasons. The model may have hallucinated. The retri…
Your AI agent doesn't have a memory. It has a transcript.
Notes from building a memory layer that forgets on purpose. Most "memory-enabled" agents don't remember anything. They re-read. Every turn, the whole …
A load balancer inspired by how Emperor Penguins survive Antarctic winters
Why I modeled a load balancer after Emperor Penguin huddles A few months ago I was reading about how emperor penguins survive Antarctic winters. Tempe…
wayback-video: Turn Any Site's History into a Video
Side project outside my usual PHP world, but worth sharing. I have a habit of Googling old websites just to see what they looked like. GitHub circa 20…
I Tested OpenAI and Anthropic Pricing Side by Side — Here's the Truth
So here's what happened: i Tested OpenAI and Anthropic Pricing Side by Side — Here's the Truth Last month I burned through $847 on a single classifica…
From Variant CSV to Review-Ready Report: A Python Workflow With Docker and GitHub Actions
Variant prioritisation often starts with a table. But a table alone does not answer the most important question: Which variants deserve closer review,…
Can AI Reason From Marker Genes? Building a Single-Cell Benchmark From PBMC3k
Most single-cell RNA-seq examples end with this pattern: load data preprocess cluster cells generate UMAP rank marker genes assign cell labels That wo…