Lunay Simão
Software Engineer · Lisbon, Portugal
I build systems that process millions of transactions and manage logistics for some of Europe's largest retail operations. I write about what happens when systems like these go wrong — and why the decisions that cause failures are almost never accidental.
Payment systems
Millions of daily transactions · ATM networks · Mobile payments
Enterprise & Retail
Logistics · ERP · System integration · Franchise migration
Cloud & Certifications
Azure AZ-900 · AZ-204 · Java · Spring Boot
Engineering failures almost never happen by accident. They happen by choice — choices made under pressure, under budget constraints, under deadlines. Understanding those choices is the first step to making better ones.
This blog exists because the people who build critical systems should be held to account — and because the stories of how those systems fail are some of the most important engineering lessons available.
The failure report
One engineering failure, deeply explained. Every two weeks.