ANSWER
AI agent or system rewrite — which costs less?
Reviewed .
A rewrite often costs more over its lifetime because delivery is followed by maintenance, support, dependency upgrades and new technical debt. An agent takes on the work without adding another application to the portfolio. The honest exception is a system that stores critical state: that core may still require a product replacement or rewrite while the agent handles surrounding work.
Step by step
- Separate build cost from lifetime ownership cost.
- Classify system of record versus rule-execution layer.
- For rule execution, compare time to first useful delivery.
- For critical state, keep the agent around the core.
- Prove a small slice with a size-P agent before funding a large path.
How an agent does this
AgenticosCore puts a size-P agent live in one to two weeks so you can measure before committing a quarter. For size G, Parallel compares outputs before any cutover.
Frequently asked questions
Do you perform rewrites?
No. If a rewrite or market product is the right answer, we say so and only take on the surrounding work when it fits.
How fast is the first useful delivery?
After approved fit, authorized access and contracted scope, a size-P agent typically has a one-to-two-week window. Dependencies and criteria are explicit in the contract.
Primary sources
- Managing legacy technology — UK Government
- Retiring service components securely — UK Government Security