When new data scientists join your team, remember to give them some breathing room for the benefit of individual and team dynamics.
First days are tough. My first job was with Uncle Sam as a Cavalry Scout for the US Army, and my first duty station was in Bavaria, Germany. On my first day, I remember walking on the streets of Germany as a 17-year old American kid whose sum total of German vocabulary was the word Gesundheit (and I didn't even know what it literally meant -- I just knew that's what you said after someone sneezed). I had no clue what was going on.
Welcome to the data science madness
Some people can easily blend into a new environment with little effort -- data scientists don't usually fit into that category. When you bring on new data scientists, you must pay attention to the individual and team dynamics at play.
Your leadership in the first few weeks with new data scientists will shape the rest of their engagement with your data science team. There are some things to be sensitive of when dealing with these new team members.
Be cognizant of data scientists' particular needs
First, many data scientists are introverts; this doesn't mean they don't like people, but keep in mind socializing drains their energy and is a distraction when they're applying their more natural talent of analyzing data. So, if you've hired them to tackle a particularly hairy problem, you'll make their life very difficult if you simultaneously force them into a lot of social situations. I know you're anxious to get them working on tough problems, but I recommend you reserve their first few weeks for socializing and somewhat light intellectual activity.
Second, data scientists don't like it when they don't know something; when you couple that with introversion, you have a situation brewing that's difficult to detect. You should spend time teaching new data scientists about the company and their job -- they know data science already (that's why you hired them).
For example, I recently started working with Chevron, and my first set of interventions is on an oil field in Bakersfield, California, working with petroleum engineers. Without previous oil and gas experience, you can imagine how I felt being dropped into this new world. I didn't even know what a nodding donkey was even though I was parked five feet away from one on my first day. And even though I'm seasoned at data science and consulting, it brought me right back to my first day of work in Germany. That feeling is fun for some people but not for me.
Plan for team growth to affect dynamics and productivity
Another situation that often escapes leaders trying to grow their data science team is what it will do to their existing team dynamic. One of the more common and unwelcome surprises is that it throws the team's balance off, which may develop into a faction you don't need in your highly performing team. This will happen very naturally as new data scientists try to find their home with existing data scientists.
If you're not in a position to grow in a balanced fashion, keep your eye on what's happening with your subgroup of data scientists (remember, you should have more than just data scientists on your team). If you sense that your data scientists are starting to isolate themselves too much from the rest of the group, you may want to interrupt this with a good team building session.
Also, consider that when you add new data scientists to your team, you now have two or more cohorts that are each at different stages of group development. Your existing team members are in the norming or performing stage, and your new members are in the forming stage. Everybody plays nice in the forming stage, so you may fallaciously believe that the new team is fitting in well. And then comes the storming stage. There is no way to avoid the storming stage, so expect it and accept it. Your productivity will temporarily slump as your team works through its conflicts, so incorporate that into your planning. For instance, you don't want your team storming when you're trying to introduce a new product or service into the marketplace. The behavioral change professional on your team should be able to help you navigate through these tricky periods of team growth.
Day one on the job is oftentimes exciting, terrifying, and fun. All of these high-flying emotions can be disruptive to your data science team, and it's up to you to influence how your team performs through the introduction of new team members. As much as you want your new data scientists to hit the ground running, a bit of breathing room will serve everyone well.
Remember: don't hit them with the hard problems on day one -- give them some time to meet people and learn about the environment. Also, work with your change leader to incorporate the inevitable shifts in team dynamics. You'll emerge from all of this with a smarter, stronger, faster team.