Self-contained MinHash implementation with band-based LSH for fuzzy deduplication of code entities. Avoids external dependencies like scipy/numpy, making it easily extractable into any Python project needing near-duplicate detection. Demonstrates non-obvious skill in implementing a probabilistic data structure from scratch with careful attention to hash seed stability and integer arithmetic.

Robust node ID normalization that applies case folding, NFKC normalization, and fixpoint iteration for combining marks. Ensures consistent IDs across different Unicode representations and case variations. This is a reusable pattern for any system that needs deterministic, collision-resistant identifiers from arbitrary strings, especially in multilingual codebases.

Atomic file write utilities (`write_text_atomic`, `write_json_atomic`) that use `os.replace` for atomicity on POSIX and fall back to copy-then-rename on Windows when `os.replace` fails due to permission errors or cross-device links. Preserves file modes and handles edge cases like read-only files. This pattern is directly reusable in any Python application requiring crash-safe file persistence.

Comprehensive security module implementing SSRF protection via custom HTTP/HTTPS connection classes that block private IP ranges and cloud metadata endpoints, URL validation with scheme whitelisting, path traversal prevention, and metadata sanitization. The SSRF guard pattern is self-contained and can be extracted to protect any Python application that makes HTTP requests based on user input.