Notes from building systems
Backend, payments, and scaling lessons from production work.
What 600k concurrent sessions taught me about Redis connections
Pool exhaustion rarely starts in Redis itself. It starts in how the application opens connections. Here's the multiplexing approach behind keeping agent apps up at peak.
Encoding EMV QR payloads with TLV, step by step
An EMV merchant QR code is a string of tag-length-value fields with a checksum at the end. Here's how the format works, and how to build one in C#.
Sending 800k push notifications in under 8 minutes
A bulk notification job is a throughput problem with a deadline. Here's how I think about batching, platform targeting, and multilingual payloads.
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New notes go up here first, then on LinkedIn.
Short write-ups on problems I run into while building payment and backend systems. Follow along, or tell me what you'd like me to write about next.