You can find really good cocktails in basements these days
Tech City is home to 6 of the world's 50 best cocktail bars.

Worship Street Whistling Shop (2 min walk from TechHub @ Campus)
cocktails inspired by the grape
hop, grain and barrel!

Happiness Forgets, Hoxton Square
after your devastator burger success, head over to the other side of the square for something slightly more civilised

We'd also recommend:
The Night Jar, 69 Colebrook row, The Zetter Townhouse

And if basements are not your thing and you'd rather walk through a wardrobe to acquire your tipple, head over to:
Callooh Callay, 65 Rivington Street.

Had too many cocktails?
Detox at Lovage