“Yes, always! “

is my initial response. I’d even say: if you discard all of the ceremonials of Scrum and have to choose 1 to re-introduce, it should be the retrospective. Without a doubt.
But I have a confession to make.

Mike Cohn wrote an article that caught my attention, since I’m currently working with 2 teams that

• have 1 week sprints.
• are small: 1 developer and 1 UX/UI specialist.
• We’re in the same room, we talk, they talk and standups, planning, refinement, development: all smooth and delivering quality as promised.

So: What to do in the weekly retro?

Confession: we choose to skip a retrospective every 2 weeks and I allowed it.
Yes, I felt bad.

At first.

But now we feel good about it. The bi-weekly retrospective is useful and with attention. It’s a nice heartbeat. We feel confident and full of trust in the way we work.
And we have agreed on reinstalling it, the minute we need it as a part of the deal.

So if anybody asks you “Could we not do a retrospective?”, your answer will be:
“No, we will always have a retro!” but, and, except when ….

A great article with many arguments by Mike Cohn, mostly about why you should do it every sprint. And a little about skipping them:
https://www.linkedin.com/pulse/does-scrum-team-need-retrospective-every-sprint-mike-cohn