Designing attendance for unreliable internet

Many schools have power cuts and patchy mobile data. An attendance system that needs a live connection to work will fail exactly when it is needed.

Record first, send later

The device saves each scan on itself first. When the connection returns, it uploads the records in a batch.

Never count twice

Each record carries a unique ID. If the same record arrives twice, because a connection dropped halfway, the server recognises it and keeps one copy.

When two devices disagree

If two records describe the same student in the same class, the earliest captured scan wins. That keeps the outcome fair and predictable.

Why this matters

Staff should not have to ask whether the internet is up before taking attendance. It should just work.