fix statefullness -> statefulness

one l

Author: paralax

README.md

@@ -113,7 +113,7 @@ Sooner or later I will complete it with the relative answers. Feel free to contr
 * Why first-party cookies and third-party cookies are treated so differently?
 * How would you manage Web Services API versioning?
 * From a Back End perspective, are there any disadvantages or drawbacks on the adoption of Single Page Applications?
-* Why do we usually put so much effort for having stateless services? What's so good in stateless code and why and when statefullness is bad?
+* Why do we usually put so much effort for having stateless services? What's so good in stateless code and why and when statefulness is bad?
 * REST and SOAP: when would you choose one, and when the other?
 * In Web development, Model-View Controller and Model-View-View-Model approaches are very common, both in the Back End and in the Front End. What are they, and why are they advisable?