The deck has evolved so much when compared to previous iterations that it doesn't even make sense to mention them. Yes, really. 

The deck itself revolves around Saheeli, Sublime Artificer's ability to create servos, coupled with Mizzium Tank, of all cards. It offers significant aggression while dodging sorcery-speed removal and, seeing how basically all of our spells are non-creatures, it'll almost always be enabled. And even if we have zero spells to cast, a single Saheeli servo is enough to crew it. 

Runaway Steam-Kin was a surprise find. I mean, in retrospect it's obvious how powerful it is, but still. It grows with almost all of our spells, and can be copied into a token (or mizzium tank) by Saheeli. With the proper hand, you can achieve almost infinite mana (or, well, infinite enough). You can also just leave the +1/+1 counters on it (or the copy!) so you have a big beater. 

The new Ral, Storm Conduit's role is copying stuff. A copied Expansion // Explosion would let you seal the match sooner, for example. It also offers some (admittedly minor) card selection, and has the potential to deal infinite damage with two Expansions and a secondary spell. His -2 is super flexible, albeit a bit on the situational side. Treat him as a secondary wincon.

Finale of Promise lets us recycle spells from our grave. Each cast counts separately towards Saheeli and Mizzium Tank, and since our mana costs are on the lower side, we often get three casts for 4 mana, usually drawing at least 1 card in the process. Truly impressive value.

We have plenty of cards to let us generate massive tokens from Saheeli in Shock, Opt, Lava Coil, and Warlord's Fury, while having significant card selection in Anticipate. 

As for the Sideboard: Narset, Parter of Veils is a great tool versus control decks. It enters early, and disrupts any draw, while giving you access to a wide margin of cards. 
Lazotep Plating is self-explanatory, really: protection from removal. It's worth using against RDW, especially if they're running the new Chandra, Fire Artisan, as she'll self-destruct if you and your planeswalkers can't be targeted. The Amass effect is also not useless, letting you chump block once.
Ugin, the Ineffable is basically the only source of enchantment removal we have access to, and it's not exactly cheap. But it also generates creature tokens that draw us cards when they die.
Lightning Strikes are an excellent substitute when you're facing either a creatureless control, or a heavy aggro, as it can go face and get rid of creatures faster.
Ionize and Negate gives us some tools to handle pesky control decks and their counters. We will lose the counterspell war, that's a given, but any ionize that gets through is one less spell for them, and 2 less damage needed for us (3 with Ral). 
I know the sideboard isn't perfect, so I'm completely open to suggestions. 

Maybeboard was removed: Augur of Bolas wasn't as good as Anticipate. Commence the Endgame usually doesn't create a large army for us, and is expensive AF. Role Reversal is far too gimmicky.

I've dropped Jhoira, Weatherlight Captain because she was slow and too vulnerable to removal, and our gameplay changed drastically. Same with Storm the Vault // Vault of Catlacan. Karn, Scion of Urza is very powerful, yes, but it usually eats up an entire turn on its own. When it works, it works, but when it doesn't it feels deader than Lava Coil vs a control deck. Anticipate often ends up working better than he does when it comes to card selection, and the tokens often don't feel powerful enough to justify the 4 mana spent on it.