An Update from Robinhood’s Founders • Hacker News Board

Re: An Update from Robinhood’s Founders

#271

Post by dirtydroog » Wed, Mar 04, 2020, 6:12 PM UTC

gshulegaard wrote: post #204

dirtydroog wrote: post #200

Earlier quoted context omitted.

If you used Scylla you'd have only needed 90 nodes. (Don't believe the instability rumours)

I've was a primary contributor on a migration of time series data to Scylla. As an anecdote, I once emailed our business contact about tracking down why we appeared to have data inconsistencies between our new (Scylla backed) and old system. I thought the e-mail got lost since we never heard back...until 8 months later (long after we had de-prioritized the migration since our old system was "good enough") asking if w…

Well, we moved to it from Cassandra. It's yet to fall over and we're querying it maybe 200k times per second. No changes were needed from the client driver side of things too. YMMV.

Re: An Update from Robinhood’s Founders

#272

Post by Ambele » Wed, Mar 04, 2020, 6:20 PM UTC

I can't help but think this glitch was a good thing and Robinhood investors would do better if they traded less anyhow. According to an OpenFolio correlational study, traders who trade more than 12 times per year make 0.5% less than traders who trade less than 12 times per year. OpenFolio was one of the first three websites to have an API integration with Robinhood portfolios.

Re: An Update from Robinhood’s Founders

#273

Post by SirLJ » Wed, Mar 04, 2020, 6:41 PM UTC

C1sc0cat wrote: post #219

malux85 wrote: post #169

Earlier quoted context omitted.

Can you give me a concrete example of a massive distributed system that has zero downtime? Because the largest distributed system I have seen and worked on was at Apple (or maybe DFP at Google) - and even though they had some of the smartest people in the world and literally billions of dollars behind them, there were still an endless list of problems and downtime events. Spoiler alert: It doesn't exist.

Dialcom (Telecom Gold) in the UK was pretty close to 100% Almost survived the big storm of 87 - unfortunately the modems where on the UPS. We built an entire new DC and had Tottenham Court Road dug up in case the Thames flooded. In fact any big telecom will have down times for a switch (central office) measured in generations

Those Silicon Valley kids can't understand reliability... Good thing my bank and my broker are not run like this... what a joke...

Re: An Update from Robinhood’s Founders

#274

Post by SirLJ » Wed, Mar 04, 2020, 6:42 PM UTC

plusplusc wrote: post #239

frockington1 wrote: post #228

Earlier quoted context omitted.

Can you name a reputable brokerage that was down all of Monday and Tuesday this week? Spoiler alert: it doesn't exist

Interactive Brokers. Well known in the financial community, but nearly unknown outside of it.

Not true: Interactive Brokers were up as always and the API was working without a flaw...

Re: An Update from Robinhood’s Founders

#275

Post by LaserToy » Wed, Mar 04, 2020, 6:46 PM UTC

yuppie_scum wrote: post #268

LaserToy wrote: post #162

Earlier quoted context omitted.

It is not about scale, it is about the fact that people lost real money. If you can’t make it work you should not be in that business, and I don’t really care how hard they work. I’m taking my account off their platform.

Nothing was stopping the Robinhood customers from opening an eTrade or TD Ameritrade account or something and doing their trading out of that platform for the duration of the outage. Robinhood isn't really an institutional platform in my understanding anyway.

How can you do it if your equity is in Robinhood?

Re: An Update from Robinhood’s Founders

#276

Post by [deleted] » Wed, Mar 04, 2020, 8:12 PM UTC

indecisive_user wrote: post #189

vinaypai wrote: post #160

Earlier quoted context omitted.

This is all true for a company that is actually pushing any boundaries as opposed to failing pathetically at a well solved problem.

Robinhood opened up stock trading to a large portion of the population that would otherwise not have been interested in traditional trading platforms with high commissions. Their success helped to pressure companies such as TD and Schwab to mostly get rid of commissions as well, which is great for the average trader I think Robinhood has a lot of problems, but to say they're not pushing any boundaries ignores the hug…

[deleted]

Re: An Update from Robinhood’s Founders

#277

Post by jcheng » Wed, Mar 04, 2020, 10:33 PM UTC

JdeBP wrote: post #225

jcheng wrote: post #40

Earlier quoted context omitted.

I read this and thought, “surely there’s an OS-level DNS cache?” Apparently not on Linux! https://stackoverflow.com/questions/11020027/dns-caching-in-...

That's misleading. The way that this has worked for decades on Linux-based operating systems and on Unices is that one installs a local caching DNS proxy, choosing one of the many available: ISC's BIND, Bernstein's dnscache, unbound, dnsmasq, PowerDNS, MaraDNS, and so forth. Every Unix system having a local caching DNS proxy was and is as much a norm as every Unix system having a local MTS. A quarter of a century ago…

The point of my comment wasn't to say "don't cache" but rather, don't expect that the OS is going to automatically do it for you (as would be the case on Windows and Mac).

Re: An Update from Robinhood’s Founders

#278

Post by techie128 » Thu, Mar 05, 2020, 2:51 AM UTC

malux85 wrote: post #195

unicornmama wrote: post #191

Earlier quoted context omitted.

Then certainly you understand the importance of SLOs, how SLAs regulate reliability and feature velocity. Let’s say I’m RobinHood. Let’s pick an SLO. I think three nines monthly SLO is a good start, that budgets ~45 minutes of down time per month. Maybe I can argue for a more aggressive SLO, but let’s pick this one - because I think it will keep users relatively happy as trades aren’t blocked for more than an hour at…

Why would they burden themselves and their feature velocity with SLOs/SLAs when they can build a 5 billion dollar company insanely quickly even though they have downtime? The users are not saying "We measured your 5 9's and I'm going to quit if you have 6 minutes more downtime" Sure they lose some users who get annoyed, but they have a 5.6 billion dollar company, some users will go, a lot more are coming

You're missing the point. Reliability and Performance are features in Financial markets. It is a key feature for brokerages which they constantly advertise to differentiate themselves. These companies lay undersea cables to shave off few milli-seconds latency and pay a very hefty premium to be colocated in the same DC/rack as the stock exchange. Therefore Performance and Reliability are inseparable.

Nobody is debating whether people will continue using RH and that was never the issue. RH has massively damaged its reputation and reputation _is_ everything.

Re: An Update from Robinhood’s Founders

#279

Post by techie128 » Thu, Mar 05, 2020, 2:53 AM UTC

SirLJ wrote: post #273

C1sc0cat wrote: post #219

Earlier quoted context omitted.

Dialcom (Telecom Gold) in the UK was pretty close to 100% Almost survived the big storm of 87 - unfortunately the modems where on the UPS. We built an entire new DC and had Tottenham Court Road dug up in case the Thames flooded. In fact any big telecom will have down times for a switch (central office) measured in generations

Those Silicon Valley kids can't understand reliability... Good thing my bank and my broker are not run like this... what a joke...

You sir have a very warped view of SV. Do not stereotype us.

Re: An Update from Robinhood’s Founders

#280

Post by infinite8s » Thu, Mar 05, 2020, 3:36 AM UTC

lkbm wrote: post #246

vbtemp wrote: post #245

On Reddit I've been trying to ask this ELI5: Why would you use RH instead of a normal, mainstream brokerage like Vanguard, Fidelity, etc that already has (1) an app and (2) commission-free trades?

Easy answer: As someone who's used Vanguard for index funds and the like for a couple decades now, I had no idea they had an app or commission-free trades. They don't market this at all. As a secondary answer, normal, mainstream brokerages have pretty bad tech, tbh. I don't expect it to be worse than Robinhood in terms of things like security, and I expect UX to be worse. (Side note: I just discovered that Vanguard a…

> Side note: I just discovered that Vanguard actually has a secret security key option hidden under Account maintenance, so I can finally switch from sms 2fa. +1 to Vanguard.

It looks like you still need security codes setup:

"You'll need to register for both security codes and security keys, however. That's because keys and codes go hand in hand—if you lose your key or don't have it, we'll need to send you a code in order for you to log on. In addition, you'll always need a code to access your accounts from a mobile device."

If an attacker can skip the security key you might as well not use one.