On any team, performance will fluctuate. People have bad weeks, get stuck on difficult problems, or have personal issues that affect their work. But sometimes, a pattern emerges. A teammate consistently fails to deliver on their commitments, submits low-quality work, or seems disengaged.
This is a difficult and sensitive situation. An underperforming teammate can be a drag on the team's velocity, damage morale, and create resentment among those who have to pick up the slack.
How you respond to this situation is a true test of your leadership potential and emotional intelligence. Do you ignore the problem? Do you complain behind their back? Or do you approach the situation with empathy and a desire to help, for the good of both the individual and the team?