SumUp
Software EngineerAppliedAug 6, 2026

Increase terminal key rotation before expiry

Security maintenance is often invisible until it interrupts a merchant’s ability to trade.

The safest maintenance path can compete with the narrow windows when devices are reachable and idle.

I only find out something needs fixing when I’m standing with a client.

Rina Agarwal · Mobile hair salon owner

Uses a portable terminal across appointments and cannot afford an unexpected inability to take payment.

What pulls against what

  • credential assurance vs. merchant uptime
  • deadline urgency vs. safe retry behavior
  • fleet scale vs. device-specific evidence
  • proactive outreach vs. merchant interruption

What is at stake

A known security-maintenance deadline is approaching for an affected device cohort. Success prevents payment interruptions without disrupting trading

Why SumUp

At SumUp, terminal availability and payment trust often depend on routine work finishing before it becomes customer-visible.

Written for

Device platform engineerSecurity-minded distributed systems engineerOperational reliability engineer

This is the setup. The work is inside.

Running it puts you in the room: the full situation and its constraints, stakeholders who push back in their own words, and the decisions that are yours to make. What you produce becomes a Day One Plan — work you can show someone instead of describing.