TraceLit

The product is a visual algorithm tracer and debugger for Python LeetCode solutions that helps fix last-mile bugs such as off-by-one errors, null pointer dereferences, and wrong boundary conditions by showing the exact line where code breaks. It sells to individual developers and students preparing for technical interviews who write their own code and need to debug failed test cases. Compared to Python Tutor it renders linked lists and trees as interactive graphs instead of memory diagrams, and compared to VisuAlgo it executes the user's own code rather than pre-built animations, delivered as a free web application during beta.

Key features

• Paste Python code and test case
• Step forward and backward line by line
• Watch variables and pointers per step
• Visualize linked lists as interactive graphs
• Visualize binary trees as interactive graphs
• Track head curr prev slow fast pointers
• Display arrays and hash maps
• Show locals table for primitives
• AI highlights buggy line and explains fix
• Supports LeetCode-style function signatures