Celsius | AI Migration Validation Service

Migrate legacy systems with AI: fast, and in a form you can verify.

Generative AI has made rewriting code fast. What remains is confirming that the migrated system produces the same results as the current one, and being able to explain why. Celsius handles what comes before and after the migration.

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Challenges we address

Challenges

When teams consider migrating with AI, these challenges tend to remain.

  1. Nobody knows the specifications

    The people who built it have left, and the design documents no longer match the system.

  2. AI output is hard to trust

    Conversion is fast, but there is no way to tell whether the result is correct.

  3. Confidential information is at stake

    Source code and design documents cannot simply be handed to AI as they are.

Where Celsius fits

Before and after

Generative AI and migration tools convert the code. Celsius takes on what comes before and after that conversion.

Celsius Before: Analysis and design
Migration AI-driven migration Generative AI / migration tools
Celsius After: Comparison and evaluation

BeforeAnalysis and design

We analyze the current system and organize the migration scope, dependencies, and specifications and logic, each backed by evidence. We then design the migration approach, along with the comparison method and draft acceptance rules.

AfterComparison and evaluation

We design how to compare the results of the current and migrated systems on the same inputs, classify the cause of each difference (implementation defect, environment difference, specification interpretation, existing defect in the current system, or cause undetermined), and compile the findings into a report written in Japanese.

How it works

Process

Five steps from analysis to evaluation, with an owner assigned to each step.

  1. STEP 1

    Analyze

    Analyze the current system with Celsius and define the migration scope

    Owner: AIGYM
  2. STEP 2

    Design

    Decide the migration approach, the comparison method and draft acceptance rules

    Owner: AIGYM & Partner
  3. STEP 3

    Migrate

    Design, implement and test with the help of generative AI

    Owner: Partner
  4. STEP 4

    Compare

    Compare the results of the current and migrated systems on the same inputs

    Owner: Partner & AIGYM
  5. STEP 5

    Evaluate

    Classify the causes of differences and report them in Japanese

    Owner: AIGYM
Decision

You review and approve the expected results and their business validity

Roles

Roles

AIGYM, the development company and you each take on a defined role.

AIGYM

  • Analysis of the current system
  • Defining the migration scope
  • Designing and supporting AI-assisted development methods
  • Designing the comparison testing
  • Difference analysis
  • Technical evaluation

Partner (development company)

  • Overall project coordination
  • Designing the migration approach
  • Building development and test environments
  • Design, implementation and testing with generative AI
  • Running comparison tests and making fixes

You (the customer)

  • Deciding the migration scope and priorities
  • Defining and approving expected results
  • Approving the use of data
  • Judging business validity

What sets Celsius apart

Features

  1. Specifications made visible, with evidence

    Analysis results keep evidence-backed facts separate from inferences and open questions.

  2. Differences are never hidden

    Differences we cannot explain are explicitly marked “undetermined.” If a significant monetary difference remains, the result is not treated as a pass.

  3. AI usage rules agreed up front

    AI is used with settings that keep your data out of model training, and credentials and personal information are never passed to AI. Materials are also checked before they go in.

  4. Start small, then decide

    Begin with a narrowly scoped AI Migration Validation, and decide on full migration once you have seen the results.

Start with an AI Migration Validation

Start small

Rather than migrating everything at once, we pick one representative process and take it all the way from analysis through comparison and evaluation. At the end, you receive a summary of what was migrated, what remains unverified, the open issues, and the outlook for a full migration. Whether to continue, change the approach or stop is your decision, made with those results in hand.

Duration and fees depend on the scope and are quoted individually. Please contact us.

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Frequently asked questions

FAQ

Q.Is Celsius a tool that converts code automatically?

No. Generative AI and migration tools handle the conversion. Celsius handles the analysis and design before migration, and the comparison, difference analysis and evaluation after it.

Q.Can you promise that the migrated system is correct?

We verify the differences from the current system and report them with supporting evidence. The final judgment on business correctness rests with you. Differences we cannot explain are explicitly reported as “undetermined.”

Q.Will our source code or data be sent to external AI services?

We agree on AI usage terms with you in advance and follow them. AI is used with settings that keep your data out of model training, and credentials and personal information are never passed to AI.

Q.Do you also review security?

We check AI-generated code against basic security rules, but for security we recommend a vulnerability assessment by a specialist firm.

Talk to us first

Contact

We are happy to help from the start, including how to run an AI Migration Validation and how to choose what to begin with.

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