Model checking is a formal method technique used to reason about the behavior of complex software systems by exploring possible system states and checking if their desired properties are satisfied. TLA+ (Temporal Logic with Assignments) is a specification language used for model checking that is known for industrial usage in companies like Microsoft and AWS. It is created by Leslie Lamport and can be used to create a basic merge queue system, which is a queueing system that takes a pull request one by one, tests them, and merges them into the mainline in order. The system has six processes and three pull requests working in parallel and eventually getting merged. The model checking process helps identify potential problems with the system, such as test failures or timing bugs, by exhaustively searching through possible states and checking if they satisfy the desired properties. TLA+ itself is a specification language, but there is another language called PlusCal that is close to programming languages and can be used for most software engineers. The merge queue system was initially designed without the "queue" part and later modified to handle test failures and add the queuing part. The model checking process presented a counter-example where a PR gets blocked and other PRs are stuck, highlighting the need to remove the offending PR from the queue. The final system is still small but has enough features to be useful. Model checking is relatively easy to start and can be used by people interested in this area, with relevant classes available in undergraduate CS courses. TLA+ is fun and easy to learn, and engineers at various levels can get useful results in 2-3 weeks after starting to learn it. The Aviator tool automates tedious developer workflows by managing git Pull Requests and continuous integration test runs, helping teams avoid broken builds and streamline cumbersome merge processes.