In 2007 & 2008 I wrote several blog entries on Pair Programming (tagged with pair programming). Pair programming solved a lot of problems for me: knowledge transfer, mentoring, code review, etc. It also solved another problem at the same time, even though I wasn't aware of it. Pairing helps reduce the number of cooks in the kitchen.
These days I'm working on a project with some really talented people. The pace at which we deliver features is far faster than any project I worked on before I joined DRW. However, I've seen two effects of having so many talented developers on the same team: wiki coding and spork sharing. (both metaphors coined by my tech lead, badams)
Wiki coding occurs when the churn on a class or component is so great that whoever commits last ends up deciding what the it should do. Wiki coding leads to inconsistent design and lack of convention. Spork sharing occurs when a fork is designed and a spoon is also needed. Instead of creating a spoon, you want to share the handle, so you create a spork instead. Now, you have no spoor or fork, you have a spork, and sporks suck. Both problems seem to stem from differing vision for the classes or components.
It appears that the more talented programmers you put on a team, the more fractured the vision for the project becomes. Of course, complexity (as well as many other factors) can also increase the fracture.
You won't catch me advocating for 'hard-working average programmers'. What I do believe is: you should stock your team with only rockstars, between 2 and 4 of them. I've worked on teams that only had 3 people. I've worked on teams with about 16. I was a consultant, I've worked on a lot of teams - big and small. My experience was that the smaller teams were much more effective, every time.
Reflecting on the past few years, I came up with the following reasons for keeping your teams small:
- New Technology: Small teams can more easily come to a decision to try a new technology. Also, if a small team selects a new technology, the entire team is likely to learn the new technology. However, an individual on a larger team may find a way to never learn the new technology and never contribute to that area of the code. Worse, a larger team may shy away from trying new technology because they cannot come to a consensus. New technology can offer productivity boosts, and missing those boosts can hurt a teams efficiency.
- Smaller Problems: Smaller teams generally implies solving smaller problems. Most problems can be broken down into smaller, less complex problems. Once the problem is broken down, it should be easier for the small teams to craft elegant solutions that can integrate to solve the larger business need.
- Improved Maintainability: Smaller teams generate less code, which allows all team members to have depth and breadth concerning a solution. Having depth and breadth allows you to easily share vision and fix broken windows.
- Ownership: Ownership isn't bad. Single points of failure are bad, but having a small team that feels ownership over an application will generally lead to higher quality and more emotional attachment to it's success.
- Context Switching: Smaller codebases maintained by small teams solving a smaller problem will context switch less, because there's nothing else to context switch to.
- Responsibility: The Bystander Effect applies to code (e.g. production bugs) as well.
- Unified Vision: In a large team it's easy to have an opposing vision and never be proven wrong. In a small team it's likely that you will agree on a vision for the project (process, technology, etc) as an entire team.
- Adding: Adding one more person to a 2 person team will likely result in a new productive team member relatively quickly. Smaller team, smaller problem, smaller codebase = easier team to join.
Sometimes I wonder if consultancies sell large teams, and then use pairing to make the large teams more effective. It's definitely my experience that large teams pairing are much more effective than large teams that aren't pairing. However, I wonder if anyone ever stopped to ask: would a smaller team have been sufficient (or, better)?
I still believe pairing is an answer to many problems. However, the best solution to making a 8 person team more effective isn't pairing. I believe that a superior solution is finding a way to solve the problem with a smaller, more effective team (or teams).