No code review worked very well given the objectives of the team. It was an R&D group who's primary objective was "demo the nifty new thing to the executives". That meant a lot of short notice requests but also a lot of throwaway code. We'd demo the thing, the exec would be like "looks great, no business case" and the repo would never be touched again. Of course, every now and then our thing WOULD get productized and the downstream team would be responsible for turning chicken-scratch code into something production worthy. Those guys hated us with a burning passion.
Was a 2.5 year project, went live at 20 months in, was on time and meet budget with more capability than originally scoped.
Many days had 2-3 hours of discussion at the whiteboard. It was informal, didn't always involve everyone.
Oddly, we had three different pms during this project. We had a hard rule of no email or contact outside of stand-up with them. Two of the three pms were able to 'work' with this setup. The head of airport IT eventually realized after two years of this that we didn't need a PM.
We had a rule that if you are doing anything novel in the code base you had to have a conversation about it with at least another dev.
We all sat within a few feet of each other in a large private office with a huge whiteboard. We used index cards taped to another dedicated whiteboard for stories and if you couldn't describe the essentials on that, you had to break the story into smaller pieces. We were allowed to build our own machines and use as many monitors as we wanted. Was an Airport billing and tariff system for a large international airport, the accounting department head, director and other users were a couple of office doors away. They rarely missed a stand-up and they had an open policy for any real time questions. Standups were informal discussions, demos, question and answers not typically for status. The status update just took one glance at the cards on the whiteboard.
The final system improved revenue by 8% in its first and every following month. The director of Accounting was brought before the Airport Authority Board to explain. Billing disputes and adjustments with airlines went from nine days a month to one. The monthly billing workload went from 18 days to 5. Instead of a senior accountant being the primary user, they were able to offload this to one junior accountant with three years experience.
Bug rate was six production bugs, zero incorrect invoices in the first year live. I don't have any data after that.
The previous rewrite attempt failed after a three year attempt.