Your Last Solo in Whatever

Forgot to turn on the god mode?

I accidentally soloed silver with....I forget which class, a vorcha i think.

Almost accidentally soloed a gold match with a batarian. fing devices.

No one joins my matches, must be my deodorant or lack there of.

I got em all and have no problems with most other matches.  I do get people joining my in progress at times, other times no.

at least if you're me, you'll eventually have someone drop in at the end of w10 or w11, to deny you the Solo challenge. Especially love it when it happens on Plat. I wish the game would just not let people join at that point, if its after w9 or so. 

Nothing new under the sun...

What's the secret to soloing Gold with the Big Slow 'Bot?

I still get surprised by the steep difficulty scaling.
Bronze solo - barely see his shields move. I can (and have!) Hex Shielded my way through games (ok, till I get the 25K).
Silver solo - mostly shrug. But eventually at higher waves, especially if not strategically positioning, there are time when I start thinking, "hmm, I may go down if I don't use an Ops pack". And I get nervous when I start getting crab stun locked.
Gold solo - 6,7,8 things hitting me at once, I eventually go down and start using all my gels.

I'll add a couple things to what is already mentioned about soloing with the GJ.

I will say movement around the map is important even more so on a slow moving character incapable of sprinting, knowing where to move around the map and use its terrain to your advantage (Abusing pillars, tall walls, etc for right hand advantage)

Be careful of long range enemy units, ravagers, atlases, scions, geth prime (To a lesser extent but still good to out range the primes as well) but the former 3 are quite deadly to the GJ.

I like using hex shield/geth turret or both when i'm on my last charge of siege pulse, if anything it's to throw off the enemy or give them some trouble getting to you, while you're on that long siege pulse cooldown.
^
Idk if that would apply to you, it would depend on your build, and if you do bother to spend those siege pulse charges or keep them on permanently for the DR. Whereas in my case I like using them offensively and use them detonate for FEs, also I take the resistance damage instead of the extra charge and the recharge speed instead of DR.

Speaking of siege pulse it's not a bad choice as well, to expend them on mooks, it'll stagger them giving you time to line up a headshot on your weapon of choice. 

Heavy melee is still good even if you're not a predominately heavy melee oriented GJ. You can at least use the heavy melee the mooks to temporarily put them on the ground (Heavy melee for a lil bit then let go is what I meant), to buy you time to give you distance between them. Especially useful to dispatch phantoms because of on host DR, they're frail when they are on the ground which better than them flipping for 10 years.

I'd say this tip would be more useful on the wider hex shield, you can use the hex shield in a way to protect yourself from receiving enemy damage in the background. For example you could be facing a phantom advancing to melee at you, but you're also within line of sight of a cerberus turret and couple centurions and troopers. If you put a hex shield in front of those enemies's line of sight, you can have free rein on the phantom that's right in front of you.

Hex shield to the side of a ladder you wanna climb, so climb up the ladder without receiving as much damage in the process. Hex shield is good form of RHA you can abuse as well.

You can get around stunlock from enemies by using stunlock immunity moves, like the act of restoring siege pulse charges, and firing off your siege pulse. It's like essentially being in devastator mode temporarily.

I believe that should be enough to instil you with some good habits, ideas and tactics to use as the big baddy stunlocking geth.

Good old DAI vs White/Cerberus/Platinum.

Disconnected 7 seconds before extraction.

The video begins at the beginning of W2 and is 17:18.