A screen that feels fast on a MacBook in a quiet office can be unusable three aisles into a distribution centre. We design for the aisle first and the office second.
The desk assumption
Most enterprise software quietly assumes a mouse, a stable connection, two free hands, and good light. Every one of those assumptions is false on a warehouse floor.
The person using the app is often standing, sometimes gloved, frequently on a signal that drops behind racking. If the interface needs precision or patience, it gets abandoned and the work goes back to paper.
Three constraints that change everything
First, target size. A control that is comfortable at 44 pixels works for a thumb; anything smaller is a miss waiting to happen, especially with gloves. Second, contrast. Fluorescent glare and low light both punish subtle grey-on-grey text. Third, latency tolerance — not average latency, but what happens in the worst 5% of moments.
When you design against the worst case rather than the average, the average gets better too. That is the practical case for mobile-first rather than mobile-also.
Designing for thumbs and cold hands
Primary actions sit in the lower third of the screen where a thumb actually reaches. Destructive actions are never adjacent to confirmations. Scan-first input beats typing wherever a camera or a barcode exists, because typing on a cold floor is the slowest path.
We also keep the number of taps to complete a stock count visible on screen. If a flow takes six taps, it should look like six taps — not surprise the user at step five with a required field.
Test where the work happens
Our rule is simple: if a flow will run in a warehouse, it gets tested in a warehouse. We have run usability sessions standing in aisles, with gloves on, on purpose-throttled connections. The findings are consistently uncomfortable and consistently correct.
The clearest signal is abandonment. If a tester puts the device down and reaches for a clipboard, the design failed — regardless of what they tell you afterwards.
Key takeaways
- Design for gloves, glare, and weak signal, not for a desk demo.
- Keep primary actions in the thumb zone and never place destructive actions next to confirmations.
- Test flows in the real environment; clipboard fallback is the honest failure signal.