01
Where this one gets misread
Prompts are the least durable part of a system. A result that depends on carefully written instructions tends not to survive a model upgrade, and the upgrade is not usually yours to schedule.
Glossary
What is prompt engineering?
Prompt engineering is the design and testing of the instructions, context and output constraints given to a model for one particular task.
Updated 21 Aug 2026
02
Questions to ask
Ask for a worked example on your own material, and the evidence needed to reproduce it.
- What breaks when the underlying model changes?
- Are prompts versioned and tested?
- Who is able to change them?
- Is the behaviour reproducible run to run?
03
How Marella uses the term
We use “Prompt engineering” only where a product mechanism or an evaluation method backs it up, and we say when the behaviour depends on how a deployment is configured.
- Backed by a product mechanism or an evaluation method
- Deployment differences flagged
What this page does not prove
- B1A definition is not a claim about how the product performs.
- B2Vendor implementations vary.
- B3Test the term against a representative workflow.
Related pages
Test the claim on your documents
Pick a real piece of work, agree what a good answer looks like, then go through the results together.