Darren Nix

Slow triathlete, climber, post-apocalyptic lit fan. Founder at 42Floors. Previously built RVmenu, Leaky, and Silver Financial.

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How I train for Ironman while doing a startup

The race I’m training for, an Ironman, consists of a 2.4 mile swim, a 112 mile bike, and a 26.2 mile run. Pros will average around 9 hours and 20 minutes to the finish line, but I’m an age group triathlete. That means that just finishing the race is often enough; finishing in the top third of my age group would be a great day. cropped37-208x300.jpg During each race, I try to ignore the hundreds of younger and fitter racers flying by. I’m just trying to keep up with the other guys in M30-34; you can tell who they are by the color-coded swim caps and the conspicuous 30-something numbers written on their calves in magic marker. For us, the race will last a little over 12 hours, during which time we will burn 8,000 calories and eat 4,000 calories of Clif Bar, Hammer Gels, Perpetuem liquid nutrition, bananas, potatoes, oranges, Gatorade’s, and flat Cokes — whatever our stomachs will tolerate.

My first step...

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Striking back at recruiter spam

Spammy emails We’ve decided on a new approach to handling recruiter spam.

Before I go on, let me say that we like working with high quality recruiters from time to time, including one fantastic freelance recruiter, Oli Ryan, who helped us find several of our key hires.

That being said, we get bombarded daily with spam calls and emails from recruiting companies. Most of these we just ignore, but some bad actors decide to contact every person on the engineering team including calling our mobile numbers. That’s unacceptable.

So, it’s time to strike back: if they waste our time, we’ll waste theirs.

The recruiter black hole It’s a simple concept: when a recruiter starts to be a pain in the ass, we just tell them to call our “HR manager” at this number:

(415) 534-6560

Give it a call. Just say you’re “John, with ABC Recruiting Solutions (Annoying By Choice)”.

A very patient individual named Derrick (a...

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The absurdity of LinkedIn

Originally published here: 42Floors

This morning I had a call with someone I hadn’t met so I Googled their name and, inevitably, clicked through to their LinkedIn profile.

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I was bemused to note that, although the search result in Google showed their full name in the title, their profile page obscured their name until I “Upgrade for full name”.

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Obscuring the name seemed especially silly given that the URL of the page includes the full name.

I wondered if LinkedIn would show me more than a radically truncated profile if I wasn’t logged in.

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So I popped up an incognito window and loaded the same URL. Voila, the full profile. It seems LinkedIn has decided that its optimal strategy is to punish registered users.

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Our homegrown A/B testing framework at 42Floors

Six months ago we created a homegrown A/B testing framework wherein we randomize traffic between three servers running different branches of our codebase. Conversion rate has since increased 251%.

Original article published here: Using split testing for office space search

My goal in sharing our results is to encourage you to take bigger risks with your A/B testing. Please treat our particular designs with skepticism; the UX that worked for us probably won’t work for you.

The original

As a search engine for commercial real estate, our site has only one goal: for visitors to find at least one office space that they like enough to contact.

Version 1

Version 1

So, the simplest measure of our success rate (our conversion rate) is the number of visitors who contact a space divided by the total number of visitors. A contact is any phone call, email, or web-based tour request. For the sake of...

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How to proxy inbound phone calls using Twilio and Rails

Because RVmenu.com is a marketplace for RV rentals, we need to let customers call rental agencies directly but we also need to be able to track each time a customer calls one of the hundreds of RV rental locations we work with. In other words, we need a proxy phone system.

Originally published at: How to use a phone proxy for RV rentals

The finished product will use a single toll-free number and long list of extension numbers. The extension numbers will be generated from the primary key of each row in our agency database model.

When a customer calls in they’ll be prompted to enter the extension number (agency ID) and their call will be forwarded on to the RV rental agency. If the customer makes a mistake and enters an invalid extension, we’ll forward the call to a general customer service number.

What users will see when we’re done


We’ll need four routes to handle the various...

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How to choose the optimal domain name using Adwords split testing

Choosing a new domain is usually a gut-driven decision. Maybe you’ll spend a few hours getting domain suggestions, check out a few Sedo auctions, build a shortlist, ask some coworkers for opinions, then pick one and hope for the best.

It doesn’t have to be that way.

Last week I wrote about how running a domain split testing experiment for my RV rental weekend project led me to a domain that performed 127% better than my personal favorite. Several readers asked for more details about the methodology so I’ve described it in detail below.


What we’re going to do is set up several domains, write identical ads on Google AdWords, and then measure click through rates.

It’s important to test domains that are significantly different from each other. For example, if you were testing FriedChicken.io vs FriedChicken.co, you’d expect to need a very, very large pool of data before...

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Going to work from home today… our office is too loud

Repost of original at 42floors

We’re about to sign a lease on a new office space for 42Floors. The architect suggested this floor plan. It looks great… unless you code.


Our current office is a 3,000 sqft 2-story townhouse with an open layout. The first floor is engineering with customer service and ops on the second floor. Even though everybody tries their best to take phone calls outside and move conversations to a conference room, it’s gotten so busy around here that the flow of ”Going to WFH today so I can get shit done” emails has become almost daily — myself included.

I’ve installed a white noise machine under my desk and a lot of us wear active noise-canceling over-the-ear headphones, but it’s still hard to focus. It’s not just the noise… there’s the steady stream of office commotion happening just over the top of every monitor.

Given that context, when I saw this open layout,...

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She’s learning to code by building a site a day. Friday was day 180.

“Hacker News is going to love you,” was the first thing I said when Jennifer Dewalt told me about her plan to leave the art world and become a coder by building a web site every day for six months straight.

HN did indeed love her, doing its best to crash her single AWS server when she posted on Day 115. Apparently the Russians love her even more, though – Habrahabr.ru (think Slashdot in Cyrillic) edged out HN + Reddit and tossed in 443 Facebook friend requests from guys named Vladimir, too. All told, she pulled in 2,140,000 pageviews in a week.

Despite being something of an online celebrity, Jen is quite the opposite of attention seeking – she’s shy and speaks softly and thoughtfully. At close to six feet tall with a sporty pixie cut, she looks like a hybrid of a typical programmer and a college volleyball player (which she was).

I’ll confess to being skeptical about her approach at...

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You’re not anonymous. I know your name, email, and company.

This is a repost of my original post at 42Floors.

Sumit Suman recently visited a site, did not sign up for anything, did not connect via social media, but got a personal email from the site the next day.

Here’s how they did it.

I’ve learned that there is a “website intelligence” network that tracks form submissions across their customer network. So, if a visitors fills out a form on Site A with their name and email, Site B knows their name and email too as soon as they land oan the site.

It all started 2 weeks ago when I got a promotional email (anonymized to avoid promotion) offering to

discretely integrate with your existing web site to identify visitors to your website.

I get B2B marketing emails all the time but what caught my eye was the inclusion of a report snapshot for 42Floors.com showing names, companies, and emails of site visitors and the information seemed plausible....

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RPGs need an auto-scaling off switch

TLDR… Single-player RPG games should include an Auto-Leveling off-switch. Instead of scaling up or down to match my character, a level 35 dungeon would stay at level 35 whether I’m level 15 or 38. This would make certain bosses impossible, which would motivate me to do side quests to level up, which would make the game longer and extend the fun. Single person RPGs would feel more like World of Warcraft where level 60 elites don’t just magically nerf themselves so that my level 15 gnome can take them on.

I just finished my second run-through of Skyrim. It’s a great game just like Mass Effect, Dragon Age, and Fallout 3 but these games all have the same problems:

A) too short

B) too easy (even on the hardest difficulty)

I understand why the developers nerfed these RPGs – most gamers don’t want to spend 200 hours and suffer frequent deaths along the way and occasionally get stuck. So the...

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