Can you give an example of a situation where you had to organize sequential or parallel processes in a project?

In one of my Java projects, I needed to organize the sequential execution of several tasks, where the result of one task influenced the next. For this, I used a chain of CompletableFuture to perform operations asynchronously while ensuring the order.

Example:

CompletableFuture.supplyAsync(() -> fetchData())
    .thenApply(data -> processData(data))
    .thenAccept(result -> saveResult(result));

In another case, I needed to run several independent tasks in parallel and wait for their completion. For this, I used ExecutorService with a thread pool and the invokeAll method:

ExecutorService executor = Executors.newFixedThreadPool(3);
List<Callable<String>> tasks = Arrays.asList(task1, task2, task3);
List<Future<String>> results = executor.invokeAll(tasks);
// process results
executor.shutdown();

This approach allowed me to efficiently manage parallelism and control the execution sequence where necessary.