What measures have you taken to improve system efficiency?

To improve system efficiency, I employed several approaches:

• Algorithm and data structure optimization — replaced inefficient loops and operations with faster ones, used appropriate data structures (e.g., dictionaries instead of lists for searching).
• Code profiling — identified bottlenecks using tools (e.g., cProfile, line_profiler) and optimized them.
• Result caching — applied memoization or external caching (Redis, Memcached) for repeated requests.
• Asynchrony and parallelism — used asyncio, multithreading, or multiprocessing to enhance performance during I/O or computations.
• Database query optimization — minimized the number of queries, used indexes, wrote efficient SQL queries.

Example of caching using functools.lru_cache:

from functools import lru_cache

@lru_cache(maxsize=128)
def expensive_function(x):
    # simulate a long operation
    import time
    time.sleep(2)
    return x * x

print(expensive_function(4))  # first call — slow
print(expensive_function(4))  # second call — fast, result from cache