Here is three ideas as a professional thank you gift you can consider for a coworker:

Desk Accessories: Consider gifting a stylish desk organizer, a set of high-quality pens, or a sleek notebook. These items are not only practical but also add a touch of professionalism to their workspace.

Gift Cards: Opt for a gift card to a popular coffee shop, bookstore, or a restaurant where they can enjoy a nice meal. This allows them to take a break and indulge in something they enjoy.

Tech Gadgets: If appropriate, tech gadgets like wireless chargers, Bluetooth headphones, or USB hubs can be well-received by tech-savvy colleagues.