We do a series of sprints to build our product, then we do 4-8 weeks of hardening sprints to really test our code and get the bugs out before we deploy it in production.
Guess what? You’re not Agile, and you’re not doing Scrum. You are using the jargon, maybe because it’s fashionable, or maybe because you’re Agile practices are misguided. But you’re not Agile.
In fact, you are doing Waterfall, masquerading as Scrum. You probably did a lot of big upfront analysis and design, followed by a coding phase (your early “sprints”), followed by a testing phase (your “hardening sprints”). You are masquerading as Scrum by using the Scrum jargon: terms like Sprint, Burndown, and Product Owner. You are applying that jargon to Waterfall. Some people call this Cragile. I call it Shcrum.