Welcome to Özkan Pakdil’s Blog

I recently migrated mpazari.com, a Turkish motorcycle classifieds site, from MySQL 8 to PostgreSQL 12. The application is a Spring Boot 4 / Java 25 GraalVM native image using hand-written SQL. The migration involved moving the existing database, adapting the MySQL-specific queries, and testing the application against a real production snapshot. The migration was completed with approximately three minutes of downtime. The main steps were: Create the PostgreSQL schema. Copy the MySQL data into PostgreSQL. Update the application queries for PostgreSQL. Run the test suite and verify the row counts. Stop the application, perform the final copy, switch the JDBC URL, and restart it. PostgreSQL’s stricter typing exposed a few old data and SQL issues that MySQL had silently accepted. The test suite helped find and fix those issues before the production cutover. ...

Green build, slow pages. That combination has annoyed me for years: Playwright happily reports 136/136 passing while the browser quietly burns 90% of one core on a badly-behaved tab, or the whole runner sits at 99% memory and everything gets suspiciously slow. Test outcomes say nothing about how much resource the tests consumed. Resource waste in CI is exactly the kind of thing you want to fail loudly, not discover from user complaints later. ...

NVIDIA offers free access to their powerful Nemotron models through their NVIDIA Build platform. In this post, I’ll walk you through how to get a free API key and configure it in VS Code to use models like nvidia/nemotron-3-ultra-550b-a55b directly in VS Code. Also you can choose any other model from here. Prerequisites VScode needs to be above 1.27 it needs to have customendpoint supporting Getting Your Free NVIDIA API Key Go to build.nvidia.com Sign in or create an NVIDIA account Navigate to the model you want to use (e.g., Nemotron 3 Ultra) Click “Get API Key” button Note: In my experience, the “Get API Key” button in the UI didn’t work properly (it appeared to do nothing). If this happens to you, here’s how to get your API key: ...

In the world of software engineering, we often obsess over the “Testing Pyramid.” We pour resources into unit tests, integration tests, and E2E suites. These are critical, they tell us that our features work as designed. But there’s a shadowy category of bugs that traditional tests often miss: the architectural “anti-patterns” and “API misuses” that don’t break functionality today but lead to system failures, memory leaks, or portability issues tomorrow. ...

After setting up CUDA on my other laptop, I moved to a different(older) machine that doesn’t have an NVIDIA GPU. This one is an everyday laptop with integrated Intel graphics, but that doesn’t mean we have to settle for slow CPU-only performance. On this machine, I switched to the Vulkan backend for llama.cpp and the results were even more dramatic than I expected. Machine Hardware Info This laptop is running Debian 13 (Trixie/Sid) with the following specs: ...