It would be more interesting to know why this stack helped the business.
Otherwise it's just a list that doesn't have much connection to the $1B part in the title.
The Stack That Helped Opendoor Buy and Sell Over $1B in Homes
11–20 of 79 posts
Re: The Stack That Helped Opendoor Buy and Sell Over $1B in Homes
#12I'm a software engineer at Opendoor- happy to answer any questions!
how many people are working there with technical stuff (dev, ops, data etc)?
Re: The Stack That Helped Opendoor Buy and Sell Over $1B in Homes
#13Just as interesting to me as the tech stack is the business stack. There have to be some really tightly-managed pipelines of deals because Opendoor is fronting capital to buy up the houses. Interesting scaling challenges there on the capital side. If Opendoor works out how to quickly vacate the newly-bought property, then automate much of the project coordination activity that is done to flip the property by automati…
Very true on the financing, and how it connects to our business. There have been plenty of companies in the past whose business model is to buy distressed houses and flip them; Opendoor is coming from a very different angle. We'd like to buy and sell houses at normal prices, do a lot more volume, and make smaller margins on each transaction than the traditional "flipping" business.
Because of that model, it's very important that we (1) have access to a lot of capital, and (2) renovate and resell the property quickly, so we can put the money to use again.
Re: The Stack That Helped Opendoor Buy and Sell Over $1B in Homes
#14I'm a software engineer at Opendoor- happy to answer any questions!
I like that you do code reviews of every commit, do you have any issues with getting people to spend time reviewing? Also, it looks like you have a very broad code base (backend, frontend, mobile, machine learning...), do all of your engineers review code for all of those areas? I've found that in small teams sometimes only one person really understands a particular section of code, which can result in poor quality c…
I think everyone on the team understands that helping unblock other engineers is as valuable as writing some code yourself. It generally hasn't been an issue getting timely review, though we have discussed tracking the average size of the PR queue as a metric if review times did worsen.
Most of the time other engineers on your team will review your code, but often engineers will pop across teams and doing code reviews if they have the time and the context. One change we've made is moving towards tagging a few engineers who might have the right context when you submit the PR.
Thanks for the tip about the title; will take a look!
Re: The Stack That Helped Opendoor Buy and Sell Over $1B in Homes
#15I'm a software engineer at Opendoor- happy to answer any questions!
Thanks for popping in! It's mentioned that the "projected cost" logic outgrew Rails, but there's no mention of what that microservice eventually wound up running. I'm curious what you had success with.
The cost structure service is actually what I've been working on recently. We spun up a fairly lightweight flask service (on our kubernetes cluster) that is capable of serving the cost structure to the rails app and for analysis. At its core, it uses a small DAG library we wrote, and on top of that has a migration framework that can represent cost structure changes over time as distinct versions that can be served simultaneously.
Re: The Stack That Helped Opendoor Buy and Sell Over $1B in Homes
#16Just as interesting to me as the tech stack is the business stack. There have to be some really tightly-managed pipelines of deals because Opendoor is fronting capital to buy up the houses. Interesting scaling challenges there on the capital side. If Opendoor works out how to quickly vacate the newly-bought property, then automate much of the project coordination activity that is done to flip the property by automati…
But it basically is flipping isn't it? Maybe they can work out how to flip a little cheaper with technology but this model only works because flipping is so hot right now. http://www.housingwire.com/articles/39523-home-flipping-hits...
It looks similar, but we're actually very different than flippers.
House flipping is about finding underpriced houses (either by having a sharp eye, or by buying distressed houses), and then optimizing the amount of money invested vs. the return.
Opendoor is much more focused on the customer experience, trying to give fair offers to every home - everyday homes, not distressed ones. We typically don't spend very long renovating our homes. We'd rather reinvent the buying and selling experience itself, and do a larger number of transactions.
More info: https://www.opendoor.com/blog/flipping-the-real-estate-indus...
Re: The Stack That Helped Opendoor Buy and Sell Over $1B in Homes
#17Re: The Stack That Helped Opendoor Buy and Sell Over $1B in Homes
#18Earlier quoted context omitted.
I like that you do code reviews of every commit, do you have any issues with getting people to spend time reviewing? Also, it looks like you have a very broad code base (backend, frontend, mobile, machine learning...), do all of your engineers review code for all of those areas? I've found that in small teams sometimes only one person really understands a particular section of code, which can result in poor quality c…
I think everyone on the team understands that helping unblock other engineers is as valuable as writing some code yourself. It generally hasn't been an issue getting timely review, though we have discussed tracking the average size of the PR queue as a metric if review times did worsen. Most of the time other engineers on your team will review your code, but often engineers will pop across teams and doing code review…
We've found mention bot to be helpful internally for intelligently selecting who should be performing reviews: https://github.com/facebook/mention-bot
Give it a try!
Re: The Stack That Helped Opendoor Buy and Sell Over $1B in Homes
#19It would be more interesting to know why this stack helped the business. Otherwise it's just a list that doesn't have much connection to the $1B part in the title.
I'd say the main direct effects were (1) we were able to iterate very fast on our internal tools, which are used by internal operators to manage each transaction; and (2) our data science setup has allowed us to price homes incredibly accurately. Many companies have estimates of a home's value, but Opendoor puts its money where its mouth is ;)
Happy to answer any more questions about it.
Re: The Stack That Helped Opendoor Buy and Sell Over $1B in Homes
#20For anyone who was wondering, they use smart locks from Schlage.
But i'm curious for two things:
-why they use those except for the different models Schlage has.
-where is Schlage api's documentation :p