Thank you @happy-song and @kparkinson. The map helped me get to the right direction. For context these maps can be chained just like any other map and that's what has to be done if you want to call

      @Test
       public void optionalsWorkingAsExpected() {
        Number x = null;
        String b = "hi there";

        var opt = Optional.ofNullable(x)
                .map(y -> y.toString())
                .map(str -> str.toLowerCase())
                .map(lower -> lower.toUpperCase())
                .orElse(null);

        assertThat(opt).isNull();

        var opt2 = Optional.ofNullable(b)
                .map(y -> y.toString())
                .map(str -> str.toLowerCase())
                .map(lower -> lower.toUpperCase())
                .orElse(null);
        assertThat(opt2).isEqualTo("HI THERE");

    }

Optional does not prevent from throwing an NPE, It makes it very easy to avoid, but you have to do your part, for example, I would refactor your code to something like this.

     public void doSomethingA(String para) {
           
           Optional<String> optName = Optional.ofNullable(para);
        
           String name = optName.orElse("Unknown");
    //At his point, you are completely sure that name is even given name or "Unknown" 
    //and can do wherever you want without being afraid of throwing a NPE
    
        }

You can use other optional Method like: optName.orElseThrow() to throw and error if your param is null, optName.orElseGet(() -> { return "Unknown" ;}); practically does the same than the example but you can add more logic to get the default value, or many other methods.