When he was around 32 years old, Leonardo da Vinci applied to the Duke of Milan, Ludovico Sforza, for a job. The duke was in need of military expertise and Leonardo’s 10-point CV emphasized his military engineering skills:
3. Also, if one cannot, when besieging a terrain, proceed by bombardment either because of the height of the glacis or the strength of its situation and location, I have methods for destroying every fortress or other stranglehold unless it has been founded upon a rock or so forth.
4. I have also types of cannon, most convenient and easily portable, with which to hurl small stones almost like a hail-storm; and the smoke from the cannon will instil a great fear in the enemy on account of the grave damage and confusion.
And I love what is almost an aside at the end of the list:
Also I can execute sculpture in marble, bronze and clay. Likewise in painting, I can do everything possible as well as any other, whosoever he may be.