How Life360 Used Slack to Establish Its Company Values

I work at Life360, where 5 values drive decisions. Everyone there knows those 5 values. Not only that, anyone there can point out countless examples of those values put in practice. How? I’ll tell you.

For a while we used “high-5 cards.” Employees received actual physical cards. On each one we’d fill out the name of another employee and describe an awesome thing they’d done. Then we’d give them the card.

It worked, kinda. Giving and receiving high-5 cards felt awesome. But by 21st century standards, it was a laborious process. Real cards were printed and distributed on a schedule. People had to write, not type. The reward came long after the fact. And cards usually went to the people you worked closest to, over and over. The practice eventually died.

In the midst of this, we started using Slack—aka. IRC 2.0—as our main communication tool. Slack is great for a lot of reasons, and it has one notable feature called “emoji reactions.” React to a message with an emoji, it’ll appear below the message in question. Simple & easy. But here comes the best part.

It also works with custom emojis. And so we created 5 new emojis, one for each Life360 value.


Artwork by Amanda Clark.

Left to right: “Know Your Users,” “Respect,” “Commit to Excellence,” “Be Accountable,” and “Take Big Swings.”

Near everything we do gets discussed in a Slack channel. Including every value-driven decision and value-embodying action. When that happens, people now react with these value-emojis.


Our Slack bot then reposts these messages to our #values channel.


Deployed on February 2nd, our Slack bot has recorded over 300 value-reactions. That’s an average of 5 per work day for a team of 50 Slackers. It feels like values have become a routine part of conversations. It’s easier than ever to show appreciation. And extraordinary contributions are surfaced across teams and channels.

Well played, emojis. Well played.

Black Mirror

I just watched the first episode of “Black Mirror.” Set in the near future, the story begins as the prime minister of England is woken up in the middle of the night. The princess of England has been kidnapped! She will die in a few hours, unless…

The prime minister fucks a pig on live TV.

I’ll let that sink in. It’s bizarre, but why not. It’s a novel plot. Of course the prime minister won’t do it, he says so himself. But who would make such a demand, and why? That’s the question I expected to see answered. Not so.

The prime minister’s temperament quickly deteriorates. He assaults his closest advisor, calls her a “bitch.” Polls shift to show 86% of the population is in favor of him fucking a pig to save the princess. His staff starts to pressure him, stating it’s the only way to ensure her safety. The prime minister breaks down. Spoiler alert!

He fucks a pig.

Which is fine. Prime ministers have been known to do that. That’s not what gets to me. What gets to me is the strategical incoherence of giving into a kidnapper’s demand. There’s a reason why governments state they don’t negotiate with terrorists. If you give in to demands, you are demonstrating that kidnapping WORKS.

“Need something? Kidnap the princess! Last time the prime minister fucked a pig to get her back, clearly there’s not much he won’t do.” Princesses and all public figures immediately become targets.

Prime ministers would never make that dumb of a mistake. F, would not watch again.

Schools Should Teach Posture

Fact: you are very likely to experience a back problem at some point in your life. One-half of all working Americans admit to having back pain symptoms each year. Tens of billions of dollars are spent on it.1

But did you know that some indigenous populations have never heard of, much less felt, back pain? That’s right. And studying their posture suggests we’re doing it all wrong. Or so The Gokhale Method argues—quite convincingly—while offering its own recommendations.

This is where schools come in. A 2007 study found that 38% of school children already had poor posture.[2] Is it any surprise? There we sit for years and hour on end. On cheap chairs. Bored out of our minds. It’s a god damn recipe for hunched backs…

But the epidemic could just as easily be reversed through awareness and simple exercises. Thanks for the history lesson teach, now can I learn to sit and stand?

1. Back Pain Facts & Statistics from the American Chiropractic Association
2. Kratenová J, Zejglicová K, Malý M, Filipová V. Prevalence and risk factors of poor posture in school children in the Czech Republic. J Sch Health. 2007 Mar; 77(3): 131-7.

Speed Writing

Writing is badass. It’s an accessible and indelible way to make a point. And you get to polish that point for as long as it takes. I enjoy that process, and admire the product. Simple, clear, penetrating words that propagate new ideas and change minds.

But I suffer from perfectionism. I write slow, edit a lot, and often give up midway through. What I share must be worthy of my romanticized view of writing, or so I feel. And yet, what I’ve realized today compelled me to write and share this as fast as possible.

My expectations are too high. Amateur musicians don’t compete with Yo-Yo Ma. Nor do they expect to delight their early audiences. Getting good takes practice, lots of it. I’ll never learn to write good essays if I never finish them. I won’t learn to penetrate people’s minds unless I share what I produce.

And so my experiment begins: Anything I publish I will write in one hour or less. Anything I start writing I will publish. No expectations, just determined practice.

Calculating a Correlation on Android

Calculating correlations is easy—especially when using a math library. If you’re like me and you like playing around with data it’s a tool you’ll want as part of your arsenal. Here we’ll be using “Pearson’s product-moment correlation coefficient.” It’s a common way to measure the linear correlation between two variables. But first a quick note about why this article targets Android.

Smartphones are the ideal data collection tool. They’re always on us so they’re easy to whip out to save any kind of information. And they’re equipped with data collecting hardware like GPS, WiFi, and sensors. AND they’re now powerful enough to process all that data themselves!… Excited yet? Let’s jump right to it!

First we’ll import Apache Commons’ math library. This will give us access to the PearsonsCorrelation class. Let’s add the following dependency to our build.gradle file:

compile 'org.apache.commons:commons-math3:3.5'

Well done! This library let’s us use a couple of data formats: RealMatrix or double arrays. Let’s use the latter.

 * We've collected a week's worth of data about ice cream consumption
 * and general happiness for a particular individual

double[] iceCreamPerDay = new double[] {
        1, // Day one, had 1 ice cream
        0, // Day two, no ice cream 😦
        0, // Etc
        0 };

// Happiness is rated on a 1 to 10 scale
double[] happinessPerDay = new double[] { 7, 5, 4, 6, 9, 9, 5 };

PearsonsCorrelation math = new PearsonsCorrelation();
double correlation = math.correlation(iceCreamPerDays, happinessPerDays);
// outputs: 0.8713708444711573

BOOM! We’re done!

The correlation coefficient will vary from -1 to 1… 1 is a perfect correlation, meaning the values rise and fall together. -1 is a perfect negative correlation, meaning when one value rises the other falls. Here’s an easy way to interpret the values between:

  • -0.1 to 0.1 indicates no linear correlation
  • -0.5 to -0.1 or 0.1 to 0.5 indicates a “weak” correlation
  • -1 to -0.5 or 0.5 to 1 indicates a “strong” correlation

So we’ve found a strong correlation between eating ice cream and happiness. At least for the person observed. I sense a Nobel Prize in our future!

Thank you for learning how to correlate today! And if you use correlations in your code, tell me about it!

Take My Money and Shut It, Spotify

I listen to music in phases. Pop songs for a week, queue classical music, then the regular Pink Floyd revival… This month’s phase was: “no music whatsoever,” and my premium Spotify account was going to waste. Bam, cancelled. What was I paying for anyway? It hit me a few weeks later.

The cycle had gone round and I was listening to my old playlists again. I’m bobbing my head getting into a flow as the first advertisement hits… “I can live with it,” I thought, so I tried for a few days. Here’s what I’ve concluded: Spotify, take my money. Anyone who gives me the choice between ads and paying, take my money now. Here’s why.

They’re Getting My Money Anyway

There’s a reason companies pay to run ads. They know they’ll make it back, and more, in increased sales. Those sales wouldn’t have happened otherwise. That’s money I wouldn’t have spent—but was convinced to through remarkable perseverance.

Ads sound like someone is doing me a favor by bringing amazing deals to my attention, but really, an ad is just a company’s way of asking for money. So in the case of Spotify, I can either give my money upfront, or get constantly asked to do so—with no end in sight.

“Why don’t you buy a new car? Look at this sound system, it’s better than yours. Come onnnnn, at least let me save you money on insurance! Not now? Fine, listen to this. I’ll be back in a few minutes.” No free service is worth being harassed.

The Best Time to Post on Hacker News

For weeks now I’ve been gathering data on Hacker News submissions, looking to answer the question: what is the best time to submit content to Hacker News?

A few hours on the frontpage can bring in tens of thousands of visitors, but only about 13% of all submissions make it (and not always for very long). You need good content for that, of course, but as you’ll see, the timing of the submissions is also worth considering.

Reaching the Hacker News Frontpage


The first thing I did was look at the percentage of submissions that reached the frontpage depending on the hour slot at which they were posted. This value peaks at 18% from 7 to 8 AM EST, which is almost a 40% increase from the all-around average.

Now, if you just want the bragging rights that come with reaching the frontpage at least once, that time slot is your best bet. You might then realize that frontpage status is fickle. With nearly 10% of submissions not making it past the 10 minute mark, and some staying featured for much longer, the average time spent on the frontpage is clearly worth factoring in.

Staying on the Frontpage


So we see submissions from 8 to 9 PM EST will stick to the frontpage for 11 hours on average, in contrast with early morning which bottoms at 6 hours. Now, we could combine this with the likelihood of reaching the frontpage and get the best of both worlds, but, as you might have realized, we’d be neglecting another important factor.

If we submit something at 8 PM and it spends 11 hours on the frontpage, most of that will be night time in the US. Whereas if we post at 7 AM, it’ll spend less time on the frontpage, but all of it will be during daytime.

To figure out which is more interesting we need just one more data set: Hacker News’ hourly traffic. That way we’ll know how much every hour of exposure is worth. Unfortunately, because I don’t have access to that information, this piece of the puzzle will have to be an approximation.

Estimating Hacker News’ Traffic

Luckily we don’t need precise numbers of visitors. Knowing how hour slots fare against each other will suffice. Our best bet then is to look at the voting activity.


It does look like US visitors command the lion share of Hacker News’ traffic, with spikes from morning until lunch, and then back again at the end of the day. The 4 PM dip is rather intriguing: is it the most productive work hour for hackers? They might also have read everything at that point, though I suppose the two aren’t mutually exclusive.

The Best Time to Post on Hacker News

We are now well equipped to answer the question that started all of this. We can look at the average traffic we would get from reaching the frontpage at any given hour, and if we factor in the likelihood of actually reaching the frontpage, we can decide on a best time to post on Hacker News to maximize our expected exposure.

Aaaand, the best time to post on Hacker News is…


9 to 10 AM EST. Generally speaking, 7 AM to noon is better than any other time.