Legacy Lens

Legacy code can be difficult to take over because important problems are often buried across thousands of files. Architecture issues, security risks, outdated dependencies, weak test coverage, poor documentation, and maintainability problems may not be obvious at first glance. Engineers can spend hours going through a repository, figuring out which warnings actually matter, and deciding what needs to be fixed first. While existing tools are useful for finding individual issues, they often do not give teams a complete picture of how ready a codebase is for modernization. LegacyLens turns a public GitHub repository into a clear, structured modernization assessment. A user simply provides a public GitHub URL, and the platform securely analyzes the repository without running its code or installing its dependencies. Its deterministic analysis engine identifies the languages and technologies being used, measures important codebase metrics, detects entry points, and looks for signals related to testing and documentation. Seven specialized analyzers then examine the repository across architecture, security, dependencies, testing, documentation, maintainability, and overall modernization readiness. Each finding is backed by specific file-path evidence, so users can see exactly where the result came from. LegacyLens also clearly marks whether a finding is deterministic or inferred. When something cannot be confirmed from static evidence alone, it is flagged for manual review instead of being presented as a definite defect. The scoring system is designed to be transparent rather than mysterious. It combines severity, confidence, and evidence strength to produce scores for seven categories, along with an overall health score from 0 to 100. From there, LegacyLens turns the analysis into a practical six-phase renovation roadmap. Each task is assigned a P0–P3 priority and includes estimated effort, prerequisites, expected outcomes, acceptance criteria, and an automation-safety classification. LegacyLens is built for software engineers, maintainers, technical leads, teams taking ownership of unfamiliar codebases, and organizations preparing for modernization projects. Through the web dashboard, users can paste a GitHub URL, review the assessment, understand the reasoning behind each score, inspect evidence-backed findings, explore an interactive architecture map, and work through the prioritized renovation roadmap. Reports can also be exported as JSON, Markdown, or standalone HTML. What sets LegacyLens apart is its evidence-first, deterministic approach. The production analysis does not rely on an LLM, does not execute repository code, and does not treat a heuristic signal as proof. This makes the results reproducible and easier to explain, verify, and trust. Most importantly, the analysis is directly connected to practical modernization work rather than simply producing a list of warnings.