Legacy Code Documentation
The system works. Nobody left knows why.
Shepard Consulting documents legacy code before a migration or rebuild. Using AI with human review, we read undocumented stored procedures, batch jobs, and scripts, map what depends on what, flag dead code, and check each finding against how the system actually runs in production. You get documentation your team or migration partner can build from.
Everything happens by email. Replies within 24 hours from matt@shepardconsulting.ai.
The Problem
What is actually going on
Somewhere in the building there is a server running jobs every night that nobody wrote down. The person who built them retired, or left years ago, or is the one person everyone is afraid to let go on vacation.
Then a lease ends, a vendor drops support, or leadership decides it is time to move to the cloud. Every migration plan starts with the same question: what does this thing actually do? Answering it by hand means senior engineers reading code line by line for months.
AI reads code fast. It can also be confidently wrong about it. The real work is reading fast and then proving each finding before anyone builds a migration plan on top of it.
What You Get
What is included
Inventory
A list of every stored procedure, scheduled job, script, and integration point in scope, with what each one reads and writes.
Plain-English documentation
What each piece does, its inputs and outputs, and the business rule buried inside it, written so an analyst can follow it, not only a developer.
Dependency map
Which jobs feed which tables, which reports break if a procedure changes, and the order things have to move in.
Dead code flagged
Code that never runs, or writes to nothing anyone reads, gets marked so you do not pay to migrate it.
Validated against production
Findings are checked against run history, logs, and real data where you give access. Anything that could not be confirmed is labeled unconfirmed, not presented as fact.
A handoff your migration team can use
Documentation your engineers or migration partner can plan from, whether the move is to AWS, Azure, Google Cloud, or a rebuild on your own servers.
How It Works
Three steps, all by email
Tell me what is in scope
The system, roughly how much code, and what is driving the move. By email is fine. I reply with a fixed-scope proposal.
Start with one module
A defined slice of the system first, so you can judge the output before committing to the rest.
Document, map, validate, hand off
The remaining modules follow the same method, with a review at each handoff.
I Try It On Me First
Run first on a public codebase
Before offering this to anyone, I ran the full method on Microsoft's public AdventureWorks sample database: about 6,600 lines of SQL with its triggers, stored procedures, and functions. It produced a trigger map, eight findings tied to specific line numbers, and a fully documented sample object.
The validation step earned its place. The first automated pass flagged 17 objects as unused. The full check found that one of them builds every customer account number. Migrating on the first pass would have dropped it. That is why every finding is checked before it goes in the deliverable, and anything I cannot confirm is labeled unconfirmed.
I am a fourth-generation tradesman who taught himself code and AI. The rule from the jobsite applies here too: you do not tear anything out until you know what it is holding up.
Read the full write-up of the practice run
I am Matt Shepard, a licensed general contractor in Colorado and the owner of Shepard Consulting. Every system I sell is one I run in my own businesses. Read the case studies.
Common Questions
Legacy Code Documentation and Migration Prep: questions people ask
What is legacy code documentation?
It is the work of figuring out and writing down what an old system actually does: its stored procedures, scheduled jobs, scripts, and the business rules inside them. It is usually the first step of a migration, because nobody can plan a move for a system they cannot describe.
Can AI really understand old code?
AI reads code quickly and is often right, and it is sometimes wrong in ways that sound sure. That is why every finding is checked against the source and against production behavior before it goes into the deliverable. AI does the first read. A person signs off.
Do you do the migration itself?
No. I document and map the system so whoever does the migration, your own team or a migration firm, starts from facts. I also work as a subcontractor for migration firms that need extra hands on the assessment phase.
Does our code leave our environment?
That is settled before any work starts. The work can be done inside your environment with tools you approve, and the data handling terms are written into the proposal.
How much does legacy code documentation cost?
It is quoted per module or as a fixed-scope sprint once I know the size of the system. Send a message describing what you run and I will reply with a quote by email.
Tell me what you need fixed
Send a message with your business name and what is not working. I will reply by email with what I would do and what it costs.
Last updated November 4, 2026.