For teams maintaining legacy systems

Finally Understand
Your Legacy Code

The original authors left. Documentation doesn't exist. And production depends on code nobody understands. diffray changes that.

Sound Familiar?

Every team with legacy code knows these nightmares

No Documentation

"This function has been here since 2015. Nobody knows what it does. Don't touch it."

Original Authors Gone

"The contractor who wrote this left 3 years ago. He was the only one who understood it."

Fear of Changes

"Last time someone modified this file, production was down for 6 hours."

Hidden Dependencies

"Why did changing this CSS file break the payment flow?!"

67%
of codebases contain code no one understands
40%
of dev time spent understanding existing code
5x
more bugs when modifying undocumented code

AI-Powered Code Archaeology

diffray's specialized agents analyze your legacy code like expert archaeologists — uncovering hidden dependencies, implicit contracts, and safe paths forward

Architecture Agent
Pattern Recognition

Identifies implicit contracts, hidden dependencies, and architectural patterns — even in undocumented code

"This function is called by 47 other files. Changes here will affect payment processing, user auth, and the admin dashboard."

Security Agent
Vulnerability Archaeology

Finds security patterns from a different era — SQL concatenation, MD5 hashes, hardcoded credentials

"This auth check was written before JWT existed. Consider modernizing to prevent session fixation attacks."

Consistency Agent
Implicit Contract Detection

Learns the unwritten rules of your codebase and flags when changes violate them

"This module expects dates in MM/DD/YYYY format, but your change uses ISO-8601. 12 downstream consumers will break."

Refactoring Agent
Safe Modernization Path

Suggests incremental improvements that won't break existing functionality

"This class can be safely split into 3 smaller modules. Here's a migration path that keeps existing APIs working."

Documentation Agent
Knowledge Capture

Documents what the code actually does, not what someone hoped it would do years ago

"Based on usage patterns, this function handles timezone conversion for Eastern US users, despite the name 'formatDate'."

Legacy Code Changes: Before & After

Modifying a 10-year-old payment module
Without diffray
Pray and deploy
  • 1.Read 2000 lines of uncommented code
  • 2.Guess what might break
  • 3.Push to staging
  • 4.Wait for bug reports
  • 5.Hotfix at 2am
3 production incidents, angry customers
With diffray
Informed confidence
  • 1.AI explains code behavior
  • 2.Hidden dependencies flagged
  • 3.Regression risks identified
  • 4.Safe refactoring suggested
  • 5.Deploy with confidence
Zero incidents, incremental modernization

Why Legacy Teams Choose diffray

Instant Understanding

AI explains what legacy code does without reading thousands of lines. Get answers about behavior, dependencies, and side effects.

Regression Prevention

Every PR is analyzed for hidden impacts. Know what will break before you deploy, not after.

Safe Modernization

Get a roadmap for incremental improvements. Modernize without big-bang rewrites that never ship.

Frequently Asked Questions

Stop Fearing
Legacy Code

Start understanding it. diffray gives you the confidence to maintain and modernize code that's been untouchable for years.