Following the onset of the COVID-19 pandemic and subsequent lockdowns, software engineers' daily life was disrupted and they were abruptly forced into working remotely from home. Across one exploratory and one confirmatory study ($N$ = 482), we tested whether a typical working day is different to pre-pandemic times and whether specific activities are associated with activity-specific satisfaction and productivity. To explore the subject domain, we first run a two-wave longitudinal study, where we found that the time software engineers spent doing specific activities (e.g., coding, bugfixing, helping others) from home was similar to pre-pandemic times. Also, the amount of time developers spent on each activity was unrelated to their general well-being, perceived productivity, and other variables such as basic needs. In our confirmatory study, we found that activity satisfaction and productivity are predicted by activity-specific variables (e.g., how much autonomy software engineers had during coding) but not by activity-independent variables such as general resilience or a good work-life balance. Additionally, we found that satisfaction and autonomy were significantly higher when software engineers were helping others and lower when they were bugfixing. In contrast, autonomy was lower during meetings and when writing emails. Also, contrary to anecdotal evidence, software engineers' satisfaction and productivity during meetings was not lower compared to other activities. Finally, we discuss implications for software engineers, management, and researchers. In particular, active company policies to support developers' need for autonomy, relatedness, and competence appear to be particularly effective in a WFH context.