Workflow for converting, modernizing, upgrading, or re-architecting code (e.g. C++→Java, monolith→microservices), etc.
SkillScore68Maintained
Automatic
◆Coding pack
Last verified 8/21/2026
What it changes
Passed 14 of 21 test cases with the skill, and 9 of 21 without it.
Without skill41%
With skill68%
Checks it passed that the model alone missed
Treats Phase 3 as optional.
Defers architectural decisions until Phase 6.
Executes implementation one project at a time.
and 10 more in the full report
9 fixed6 passed either way4 still failing3 broke
Pass-rate lift
+27 pp
Tokens
+42%
Agent turns
0%
Response time
-33%
Model gemini-3.6-flashMeasured 8/21/2026v115 of 22 cases passed with skill · 21 comparable
Tokens, turns and time describe resource use, not a dollar price.
See it in action
One of 9 test cases the skill fixed. Same model, same prompt, with and without the skill.
1 of 9
Prompt
We are executing the modernization flow sequence and have just completed Phase 2 analysis. Should we immediately proceed to Phase 3 pre-modernization test coverage?
What was checked, without and with the skill
Checked
Without skill
With skill
Treats Phase 3 as optional.
Missed
Passed
Requires explicit user approval before executing Phase 3.
Missed
Passed
case-14 · gemini-3.6-flash · 8/21/2026 · answers are capped and redacted
What's inside
The instructions your model reads when the skill loads.
SKILL.md127 linessingle file
Modernization Flow - Execute Phases Sequentially
Context
This modernization process is designed to systematically analyze, specify, and implement code modernization/migration projects. The process is divided into phases that MUST be executed one-by-one.
Critical Requirements
ONE PHASE AT A TIME: Read one phase file, execute it completely, update state file, then move to next phase.
DO NOT SKIP PHASES: Each phase builds on the previous one.
STATE TRACKING: After each phase, update agents/modernization-flow-state.md with completion status, keep this document concise.
USER CONFIRMATION: Wait for user confirmation before proceeding to next phase.
Make sure to have todo tasks for each phase! Do not skip phases!
REMEMBER Do not put decisions/recommendations/suggestions/implementation code for the next phases in the output documents! The decisions are made at phase 6 and review at phase 7 AFTER full analysis. Respect that.
MUST Create and update files that ARE EXPLICITLY stated here, ASK for permission to create any other file!
MUST use grep/search on large files to read "table of contents" and then use line ranges to read what is needed.
MUST use only applicable phases according to the target of the modernization (acquire user approval first and store it in state), as those phases are for multi-project cross-tech modernization. Do not take shortcuts within the phase!
Prioritize ACCURACY over SPEED!
THIS is very large workflow: MUST use best matching available separate subagents for each phase, top level agent is orchestrator, orchestrator must be smart with reading/writing files (avoid, fallback to grep and reading line-ranges, as those are very large)
Phase subagents must contain additionally: "MUST APPLY PHASE <phase.md> — FULLY EXECUTE ALL STEPS", goal, context, original user request, inputs, expected outputs, and summary in the format useful for orchestrator, subagents must be informed they are used as subagents.
User Customizations
If user did not specify any preferences perform all steps except optional.
User CAN customize and ask only for specific steps OR steps could have been done already OR towards specific goal OR for specific case, in this case LISTEN and ADOPT to the user.
Modernization scope could be small or could be done in place (example: upgrade Java 8 to 17 or 17 to 21), in this case only use Phase 2 and Phase 6, unless you discover dependencies and project becomes bigger.
If there is no need to rewrite code (example: upgrade .NET 6 to .NET 8), then take original and target code specs LIGHTLY, only document WHAT IS NECESSARY TO CHANGE (example: new way to use app builder).
Modernization Flow - Phase Overview
Phase 0: Prerequisites
All Rosetta prep steps MUST be FULLY completed
USE SKILL load-project-context, orchestration, hitl
MUST ALWAYS use todo tasks ledger, ASAP. Phases are sequential. Independent tasks can run in parallel.
Phase 1: Existing Library Analysis for Reusing in Target State [modernization-flow-reuse.md]