Software Engineer (Safety-Critical)

Calder Mobility · Rail and transit

Timetable optimisation for regional rail, where the output is checked by a human before it moves a train.

BackendSenior (5–9 yrs)HybridPermanentNo sponsorship

Salary band

£75,000 – £92,000

Location
Leeds
Pattern
Hybrid
Posted
25 Aug 2026 (9d ago)
Process
3 stages, listed below
Apply for this role

No account needed. One of us reads it before anything reaches the company.

The work

A timetable is a scheduling problem with a very long list of constraints, some of which are legal.

Worth knowing

  • Two days a week in Leeds.
  • Feedback loops are long. A change ships to a real railway on a quarterly cycle.

Must have

  • Software in a safety-related domain
  • Optimisation or constraint solving
  • Rigour about correctness

Nice to have

  • Rail, aviation or automotive
  • CENELEC EN 50128

Interview process

If the client adds a stage after you’ve started, we’ll tell you, and you can withdraw.

  1. 01

    Intro call

    30 min

    Their questions and yours. No competency framework.

  2. 02

    Technical conversation

    60 min

    Walk through something you built. No live coding.

  3. 03

    Team and offer

    45 min

    Meet the people you would work with, talk numbers.