Performance

Master Go context keys with custom types, avoid collisions using empty structs, and learn accessor patterns for safe request-scoped values.

Understand why io.Reader takes a byte slice parameter instead of returning one. Learn about heap allocations and buffer reuse in Go streams.

Speed up Python module imports with __getattr__ from PEP 562 for lazy loading, deprecation warnings, and dynamic attribute access.

Discover a simpler alternative to functional options: method chaining with builder-style configuration that's 76x faster and easier to understand.

Prevent memory leaks in Python descriptors by using weakref to avoid hard references that prevent garbage collection of validated objects.

Optimize Django model saves with update_fields parameter to generate leaner SQL queries and improve performance in tight update loops.

Learn from a production outage caused by loading large CSV files into memory. Stream process files to prevent OOM errors and crashes.

Use Python's urlsplit instead of urlparse for faster URL parsing by skipping the rarely-needed params component in URL decomposition.

Understand CPython list memory allocation: how lists store pointer references, grow dynamically, and when pre-allocation with [None]*n helps.

Avoid memory leaks when caching instance methods with lru_cache by making cache containers local to instances instead of global.

Learn how Python's string interning optimizes memory by caching strings and using sys.intern() for custom string caching to improve performance.