Engineering notes
Technical decisions, architecture patterns and lessons from systems I've built. The case studies show what was built; these notes explain why it was designed that way — constraints, tradeoffs and what went wrong included.
Featured note
Thera Architecture · Backend · Reliability
How Thera turns one purchase across several independent stores into per-store orders — a preflight, idempotency at two levels, compensation and careful locking instead of one giant database transaction.
In this note
Brainex Thera Argus Security · Backend
Hiding a page from a role is good UX and no protection at all. Where the real checks live in a multi-tenant system, why they should fail closed, and how to test the boundaries rather than the buttons.
Thera Brainex BYC Internationalization · Frontend
Translation is the easy part of a bilingual product; direction is what breaks layouts. Five practices for English/Arabic interfaces with right-to-left layouts, and the checks that keep them from regressing.
| System | 01 Designing multi-store checkout as a saga | 02 Role-aware UI is not authorization | 03 One interface for English and Arabic |
|---|---|---|---|
| Thera | Yes | Yes | Yes |
| Brainex | No | Yes | Yes |
| Argus | No | Yes | No |
| BYC | No | No | Yes |
Details from employer and client systems are generalized; examples from Thera, my own product, go deeper. Code samples are simplified illustrations, not production source.