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Jozef ehj

Studies and Development Engineer

10 essays

career pathMay 21, 2026

The Long Haul: From Dev to Architect, No Bullshit

Forget the platitudes. Here's what actually shifts your trajectory from just writing code to owning systems, seen through the lens of someone who’s been on call too many times.

5 min read
Systems Optimization & Performance EngineeringMay 20, 2026

The Notification Grind: Go, Node, and RabbitMQ in Multi-Tenant Hell

Remember that Tuesday at 2 AM? The one where a minor tenant's custom webhook brought down notification delivery for everyone? Yeah. We ended up deep in the trenches, comparing Go and Node.js for a critical RabbitMQ-backed service.

8 min read
Systems Optimization & Performance EngineeringMay 19, 2026

Cutting Through the Noise: A Late-Night Rant on Directness in Systems

Another 3 AM production incident survived. Time to talk about why we make our systems so damn complicated, and why sometimes, the most elegant solution is the one that just gets straight to the point.

6 min read
Systems Optimization & Performance EngineeringMay 18, 2026

AI Coding Assistants Fail at Production Debugging

AI coding assistants generate correct-looking code but often fail in production debugging. Learn why runtime profiling, system constraints, and execution paths matter more than generated solutions.

3 min read
Tech_NewsMay 17, 2026

Google Chrome Installed a 4GB AI Model on Your PC Without Asking

A security researcher found a 4GB file hiding inside Chrome called weights.bin. Nobody asked for it, nobody was told about it, and deleting it does nothing. Chrome just downloads it again. Here is the full story behind Google's most controversial AI move yet.

Tech_NewsMay 16, 2026

Cerebras IPO: The $95 Billion AI Chip Debut That Changes Everything

A dinner-plate-sized AI chip, a $20 billion OpenAI contract, and a 68% first-day surge. Cerebras just pulled off the biggest US tech IPO in seven years, and the story underneath the numbers is more interesting than the headline.

12 min read
Code SnippetsMay 16, 2026

PostgreSQL Peer Authentication Failed Fix

Learn how to install PostgreSQL and fix the “Peer authentication failed for user postgres” error on Linux systems using simple configuration changes and proper user setup.

7 min read
Code SnippetsMay 14, 2026

Oracle Free ARM VM Capacity Error Fix

Automatically create Oracle free VMs when regions are saturated. Use GitHub Actions and scheduled retries to keep attempting instance creation until capacity becomes available.

5 min read
Systems Optimization & Performance EngineeringMay 14, 2026

From 500ms to 900ms: How AI-Assisted “Optimizations” Turned a Fast Query into a Slow One — and What Brought It Back to 43ms

An API endpoint went from 500ms to 900ms after AI-suggested “optimizations,” until removing ORM abstraction and switching to raw SQL reduced it to 43ms, revealing how performance depends more on system understanding than generated fixes.

5 min read
Systems Optimization & Performance EngineeringMay 14, 2026

It worked on localhost. Obviously.

Localhost is a comfortable, consequence-free fantasy. Production is where software goes to find out what it actually is. A 3am field report from someone who has been profiling things nobody asked them to profile.