// compare tasksFromAPI ans tasks, add and delete delta
// search for added tasks
for _, latestTask := range latestTasksFromAPI {
    var taskExists bool
    for _, currentTask := range service.Tasks {
        if latestTask.Data.ID == currentTask.Data.ID {
            taskExists = true
            break
        }
    }
    if !taskExists {
        ... NEW TASK
    }
}

// search for deleted tasks
for i, currentTask := range service.Tasks {
    var taskExists bool
    for _, latestTask := range latestTasksFromAPI {
        if latestTask.Data.ID == currentTask.Data.ID {
            taskExists = true
            break
        }
    }
    if !taskExists {
                ... DELETED TASK
    }
}

// compare tasksFromAPI ans tasks, add and delete delta
// search for added tasks
for _, latestTask := range latestTasksFromAPI {
    var taskExists bool
    for _, currentTask := range service.Tasks {
        if latestTask.Data.ID == currentTask.Data.ID {
            taskExists = true
            break
        }
    }
    if !taskExists {
        ... NEW TASK
    }
}

// search for deleted tasks
for i, currentTask := range service.Tasks {
    var taskExists bool
    for _, latestTask := range latestTasksFromAPI {
        if latestTask.Data.ID == currentTask.Data.ID {
            taskExists = true
            break
        }
    }
    if !taskExists {
                ... DELETED TASK
    }
}