Metallurgy

The Industrial Age has just begun for the Umbralans. Mining and metallurgy have allowed so many other inventions to be made: lightweight planters for farming, pumps and plumbing, reinforced concrete for cheaper construction. It has also brought about advancements in glassworks. Engineers are prototyping steam engines and clockwork-based machines. Smiths are creating alloys now to further maximize the use of resources.
Ask any average Umbralan and they will tell you that smiths and smithing is what separates them from their hunter-gatherer ancestors. They skipped over the Agricultural Age because there isn't farmland in the tundra.

Utility

The most obvious advancement that metallurgy has brought about are hot- and wethouses. These metal and concrete structures are where the majority of the population's food and medicine is grown. Inside, the houses simulate the cave and geothermal spring environments that these crops thrive in. Attempts have been made to raise cave fish in these houses, but none have been hugely successful.
Because of the nearby ocean and plenty of snow and ice, scientists and engineers are experimenting with steam-powered engines and generators. Unfortunately, they haven't quite perfected it yet. Burning animal fat and trash remains primary fuel and heat sources.
Houses of the elite have rudimentary indoor plumbing. Lower classes don't have that luxury, yet most neighborhoods now have a communal water pump.
Umbralans have been making and using glass containers and jewelry for a while now. But with metallurgy came the ability to efficiently make flat sheets of glass (a method called float glass in the real world). New buildings have windows, and important buildings are adding them. They're a necessity for hothouses to make sure the plants get ample light. Of course, as much as Umbralans like their moonlight, they simultaneously added thick drapes to keep sunlight out during the day.
In secret, color-sighted glassmakers experiment with colored glass. The results are beautiful if under-appreciated by the general populace. The Order now regularly uses chips of colored glass in their color vision tests.