Magento 2 admin grid timeout – orders grid with 500k records
The admin panel timed out when trying to open the orders list. 30-second timeout. The database contained 500,000 orders accumulated over 5 years. Fix time: 3 hours.
- Published in Magento / Adobe Commerce
Magento 2 wrong VAT for EU B2B customers – tax configuration
A B2B shop was charging 23% VAT to customers from Germany and France who provided EU VAT numbers. Under the reverse charge principle, VAT should be 0% for EU businesses with a VAT number. The problem generated customer complaints and tax risk. Fix time: 8 hours.
- Published in Magento / Adobe Commerce
Magento 2 mixed content – HTTP resources blocked on HTTPS page
After moving the shop to HTTPS, product images and CSS stylesheets stopped loading in Chrome. The console showed hundreds of Mixed Content errors. The shop looked broken. Fix time: 1 hour.
- Published in Magento / Adobe Commerce
Dijkstra’s algorithm – shortest path in a graph, PHP implementation
Dijkstra’s algorithm is a classic shortest path algorithm for weighted graphs with non-negative weights. It runs in O((V + E) log V) with a priority queue, where V is the number of vertices and E the number of edges. Practical applications include routing, GPS navigation, recommendation systems and network optimisation. I show a PHP implementation with a priority queue and two real usage examples.
- Published in Algorytmy