Design a distributed crossword fill solver

## Scenario You are building a service that fills a crossword-like grid with words. - The board size is not specified; assume a **medium** board around **50×50**. - There are about **100 word slots** (across + down) that must be filled. - You have a **dictionary of ~1,000,000 words**. - A word slot is a sequence of contiguous cells; slots intersect at shared cells. - Goal: **find any one valid complete filling** (not all solutions). ## Requirements 1. Return **one** complete assignment of words to all slots such that: - Each slot is filled by a dictionary word of matching length. - Intersections have the **same letter** from both words. - (Optional, clarify in interview) Whether a word can be reused in multiple slots. 2. Discuss why a single machine may be insufficient (time/memory) and design a **distributed** solution. 3. Explain how you would: - Represent the problem and constraints - Prune the search space - Parallelize the search across machines - Detect completion and handle failures