Offline-First Edge Design Keeps Mega-Event Badge Scanning Running Despite Venue Wi-Fi Failures

·2 views

Large events with 10,000 or more delegates often overwhelm venue Wi-Fi, causing cloud-dependent badge validation to slow or time out. The article argues that event registration systems should instead store attendee data locally on edge devices so each scan is checked without waiting on an internet connection. It describes using passive UHF RFID portals that validate against this local buffer in under 5 milliseconds. Scan data is queued locally and synced to the central cloud asynchronously once connectivity is restored, so the system keeps working even if the network fails. The approach is reportedly being used at exhibitions in Riyadh and Jeddah, including the 25th WPC Energy Congress.

Read the full story at DEV Community

This is an AI-generated summary. ShortSingh links to the original source for the complete article.

Discussion (0)

Editing a running Bash script in place can crash or misexecute it

A developer reported that adding a comment to a shell script that was actively running caused a sixteen-minute job to fail with a syntax error. Bash keeps a byte offset into the open file rather than a line number, so changing the file mid-execution makes it resume at the wrong position. A simple demonstration showed a stray command running and a line executing a second time. The fix is to write a new version to a temporary file in the same folder and rename it over the original, since a running process holds the old file by its inode. In-place write methods such as shell redirects are the ones that cause this problem.

0 comments Read more at DEV Community

ProgrammingDEV Community ·

Fragmented school attendance records cause morning confusion, argues data-consistency case

A DEV Community piece contends that school attendance problems stem from the same student-presence fact being recorded across paper registers, staff chats, and office spreadsheets without syncing. The author frames this as a distributed-systems issue lacking a single source of truth, with humans acting as the message bus. Suggested fixes include one authoritative attendance record tied to a stable student ID, marking at first-period roll-call, and typed statuses such as absent, late, or leave. The article also promotes OROO Campus, a free school ERP platform, as a tool to centralize attendance alongside other school management functions.

0 comments Read more at DEV Community

ProgrammingDEV Community ·

System Design Basics: Scaling, Sharding, and the Trade-offs Architects Face

A startup's single-server API handled early growth well, but a viral surge tripled traffic and repeated vertical upgrades eventually hit a hardware ceiling. The resulting single point of failure caused a six-hour outage on the company's busiest day. The article explains that vertical scaling is simple but limited, while horizontal scaling has no fixed ceiling yet requires stateless applications and a different architecture. It also covers load balancing and the practical advice to scale vertically until costs rise, then design for horizontal distribution. The core message is that architectural choices must be made before traffic forces them.

0 comments Read more at DEV Community

ProgrammingDEV Community ·

Streaming Markdown in Vue: Rendering LLM Tokens Without Flicker

A DEV Community post by Simon He, published November 3, examines how to render streaming Markdown output from large language models inside a Vue application. The piece focuses on the flicker problem that can occur when tokens arrive incrementally and the interface re-renders the partially formed Markdown. It is tagged under Vue, AI, JavaScript, and web development. The article is listed with two reactions and an estimated reading time of five minutes. The source text provided is only a short excerpt, so the specific techniques and conclusions it proposes cannot be confirmed from this material alone.

0 comments Read more at DEV Community