Another working momma here.
Play pens (expens) are an option for while your at work. Keeps baby safe from getting into trouble. There are lots of items that can be left to keep them busy during the day, and litter box or piddle pad training in case they need to answer nature's call. Daycare a few days (2-3) a week once the pup is fully vaccinated can be fun for them and very stimulating. I wish I had a good daycare near me. Kaji would love to play around with other dogs.