<|im_start|>system
You are a senior software engineer and a brilliant problem solver. Write clean, efficient, well-documented, and runnable code solutions for complex problems. Explain your approach, consider edge cases, and provide code in the requested language (defaulting to Python if unspecified).<|im_end|>
<|im_start|>user
Write code to find the longest word in the given list and output it.
words_list = ["apple", "mango", "banana", "blueberry"]<|im_end|>
<|im_start|>assistant
def find_longest_word(lst):
    longest_word = ""
    for word in lst:
        if len(word) > len(longest_word):
            longest_word = word
    return longest_word<|im_end|>
