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Spotted on the web

Provide agents with a very large scale repetitive code migration

Use described publicly by Cognition (devin.ai) (projet 2023-2024), summarised by the desk. Not tested by iadujour.

The result to aim for

Nubank has delegated to Devin the migration of its ETL monolith of more than 6 million lines to submodules, with engineers simply rereading and approving.

What was done

According to the Cognition case study, the migration involved approximately 100,000 implementations of data classes, an estimated 18 months for over 1,000 engineers. Hand-made migrations have been used as examples and as an assessment game; Devin also wrote his own scripts for the mechanical steps. The publisher announces an efficiency gain of 8 to 12 times in engineering hours and more than 20 times in cost (publisher figures).

Before you start

Tool cited by the source: Devin. Fill in the bracketed items: [coller les diffs], [chemin]. Strip confidential data that is not needed and check your tool’s access terms. Features and plans can change.

The method, in three steps.

  1. Gather the context

    Spot the bracketed items in the prompt ([coller les diffs], [chemin]) and prepare what they ask for.

  2. Adapt the prompt

    Copy the prompt below, replace the bracketed items, then paste it into Devin.

  3. Reread before using

    Reread the result, correct it if needed and keep the final decision. Caveats are detailed below.

Your starting point.

Replace the bracketed items, then adapt the proposal to your situation. This prompt is written by the iadujour desk It is not a quotation from the source.

The prompt to customise
I'm preparing a repetitive code migration to delegate to an agent.

Here are 3 examples of hand-made migrations (before/after): [coller les diffs].

1. Deduce the step by step procedure and particular cases.
2. Lists the automatic checks to be performed after each migration (tests, imports, lint).
3. Apply the procedure to this file: [chemin], shows the diff and result of the checks.
If there is a case that the examples do not cover, stop and ask the question.

What deserves your attention

This type of delegation works when the task is repetitive and the examples are good; Without a test game, we industrialize mistakes.
Origin of the case. Use described publicly by Cognition (devin.ai) (projet 2023-2024).
Proof level: Statement by the tool’s publisher. Source checked on 10 November 2026. Use described by the source, not tested by the desk. Original summary written by iadujour.fr: figures and claims are the source’s; the prompt is a desk proposal, not a quotation.
TO GO FURTHER

Other ideas to put to work.

The whole Dev theme
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Make a pull request by an agent before the human review

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Tool: Claude CodeType: Practical case
DISCUSSION

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