This device measures:
-CO2 concentration
-relative humidity
-atmospheric pressure
-temperature
I spent ~$200 on Amazon. It pairs with your phone and you can watch data come in every minute or so.
https://t.co/aoXjyq8kdu
I recently bought one of these air quality monitors and got to take it out for some measurements!
I'll share some findings in this thread.
CCing @CO2Guerrillas here, in case they would like to share.
This device measures:
-CO2 concentration
-relative humidity
-atmospheric pressure
-temperature
I spent ~$200 on Amazon. It pairs with your phone and you can watch data come in every minute or so.
https://t.co/aoXjyq8kdu
A great way to see how much clean air you are getting is to measure CO2 concentration.
Too high -> you could use more ventilation -> open some windows!
Outdoor CO2 concentration should be about 400 ppm. I haven't calibrated my device yet, so I measured ~470. Close enough.
<800 is good for indoors. Something like 2000 is very bad.
https://t.co/oZAkVnr9ts
If I crack some windows, even just barely, it gets down to ~600 ppm very quickly, and my heater can keep the apartment ~70 F no problem.
CO2: 937 ppm.
Not great, not horrible. Surprisingly (to me), this place had the highest CO2 on my trip. It did have a purifier, which was nice.
~700 ppm. Still good.
650 ppm. Not bad!
Fun fact: this shop is 103 years old now.
Basically the same results in both: 650-700 ppm
620 ppm. Still not bad!
The doors open often, and the AC was on.
560 ppm.
Very nice! Especially since my device reads ~470 outside.
Took this sample in the essential ideology section.
520. Still good!
The whole store had their AC up very high. I could see many of the signs shaking due to airflow inside. I assume they were piping in outdoor air.
Follow these people instead of me to get some real science:
@kprather88 @jljcolorado @ShellyMBoulder @CO2Guerrillas @jksmith34
More from Tech
I think about this a lot, both in IT and civil infrastructure. It looks so trivial to “fix” from the outside. In fact, it is incredibly draining to do the entirely crushing work of real policy changes internally. It’s harder than drafting a blank page of how the world should be.
I’m at a sort of career crisis point. In my job before, three people could contain the entire complexity of a nation-wide company’s IT infrastructure in their head.
Once you move above that mark, it becomes exponentially, far and away beyond anything I dreamed, more difficult.
And I look at candidates and know-everything’s who think it’s all so easy. Or, people who think we could burn it down with no losses and start over.
God I wish I lived in that world of triviality. In moments, I find myself regretting leaving that place of self-directed autonomy.
For ten years I knew I could build something and see results that same day. Now I’m adjusting to building something in my mind in one day, and it taking a year to do the due-diligence and edge cases and documentation and familiarization and roll-out.
That’s the hard work. It’s not technical. It’s not becoming a rockstar to peers.
These people look at me and just see another self-important idiot in Security who thinks they understand the system others live. Who thinks “bad” designs were made for no reason.
Who wasn’t there.
The tragedy of revolutionaries is they design a utopia by a river but discover the impure city they razed was on stilts for a reason.
— SwiftOnSecurity (@SwiftOnSecurity) June 19, 2016
I’m at a sort of career crisis point. In my job before, three people could contain the entire complexity of a nation-wide company’s IT infrastructure in their head.
Once you move above that mark, it becomes exponentially, far and away beyond anything I dreamed, more difficult.
And I look at candidates and know-everything’s who think it’s all so easy. Or, people who think we could burn it down with no losses and start over.
God I wish I lived in that world of triviality. In moments, I find myself regretting leaving that place of self-directed autonomy.
For ten years I knew I could build something and see results that same day. Now I’m adjusting to building something in my mind in one day, and it taking a year to do the due-diligence and edge cases and documentation and familiarization and roll-out.
That’s the hard work. It’s not technical. It’s not becoming a rockstar to peers.
These people look at me and just see another self-important idiot in Security who thinks they understand the system others live. Who thinks “bad” designs were made for no reason.
Who wasn’t there.
A brief analysis and comparison of the CSS for Twitter's PWA vs Twitter's legacy desktop website. The difference is dramatic and I'll touch on some reasons why.
Legacy site *downloads* ~630 KB CSS per theme and writing direction.
6,769 rules
9,252 selectors
16.7k declarations
3,370 unique declarations
44 media queries
36 unique colors
50 unique background colors
46 unique font sizes
39 unique z-indices
https://t.co/qyl4Bt1i5x
PWA *incrementally generates* ~30 KB CSS that handles all themes and writing directions.
735 rules
740 selectors
757 declarations
730 unique declarations
0 media queries
11 unique colors
32 unique background colors
15 unique font sizes
7 unique z-indices
https://t.co/w7oNG5KUkJ
The legacy site's CSS is what happens when hundreds of people directly write CSS over many years. Specificity wars, redundancy, a house of cards that can't be fixed. The result is extremely inefficient and error-prone styling that punishes users and developers.
The PWA's CSS is generated on-demand by a JS framework that manages styles and outputs "atomic CSS". The framework can enforce strict constraints and perform optimisations, which is why the CSS is so much smaller and safer. Style conflicts and unbounded CSS growth are avoided.
Legacy site *downloads* ~630 KB CSS per theme and writing direction.
6,769 rules
9,252 selectors
16.7k declarations
3,370 unique declarations
44 media queries
36 unique colors
50 unique background colors
46 unique font sizes
39 unique z-indices
https://t.co/qyl4Bt1i5x
PWA *incrementally generates* ~30 KB CSS that handles all themes and writing directions.
735 rules
740 selectors
757 declarations
730 unique declarations
0 media queries
11 unique colors
32 unique background colors
15 unique font sizes
7 unique z-indices
https://t.co/w7oNG5KUkJ
The legacy site's CSS is what happens when hundreds of people directly write CSS over many years. Specificity wars, redundancy, a house of cards that can't be fixed. The result is extremely inefficient and error-prone styling that punishes users and developers.
The PWA's CSS is generated on-demand by a JS framework that manages styles and outputs "atomic CSS". The framework can enforce strict constraints and perform optimisations, which is why the CSS is so much smaller and safer. Style conflicts and unbounded CSS growth are avoided.
The 12 most important pieces of information and concepts I wish I knew about equity, as a software engineer.
A thread.
1. Equity is something Big Tech and high-growth companies award to software engineers at all levels. The more senior you are, the bigger the ratio can be:
2. Vesting, cliffs, refreshers, and sign-on clawbacks.
If you get awarded equity, you'll want to understand vesting and cliffs. A 1-year cliff is pretty common in most places that award equity.
Read more in this blog post I wrote: https://t.co/WxQ9pQh2mY
3. Stock options / ESOPs.
The most common form of equity compensation at early-stage startups that are high-growth.
And there are *so* many pitfalls you'll want to be aware of. You need to do your research on this: I can't do justice in a tweet.
https://t.co/cudLn3ngqi
4. RSUs (Restricted Stock Units)
A common form of equity compensation for publicly traded companies and Big Tech. One of the easier types of equity to understand: https://t.co/a5xU1H9IHP
5. Double-trigger RSUs. Typically RSUs for pre-IPO companies. I got these at Uber.
6. ESPP: a (typically) amazing employee perk at publicly traded companies. There's always risk, but this plan can typically offer good upsides.
7. Phantom shares. An interesting setup similar to RSUs... but you don't own stocks. Not frequent, but e.g. Adyen goes with this plan.
A thread.
1. Equity is something Big Tech and high-growth companies award to software engineers at all levels. The more senior you are, the bigger the ratio can be:
2. Vesting, cliffs, refreshers, and sign-on clawbacks.
If you get awarded equity, you'll want to understand vesting and cliffs. A 1-year cliff is pretty common in most places that award equity.
Read more in this blog post I wrote: https://t.co/WxQ9pQh2mY
3. Stock options / ESOPs.
The most common form of equity compensation at early-stage startups that are high-growth.
And there are *so* many pitfalls you'll want to be aware of. You need to do your research on this: I can't do justice in a tweet.
https://t.co/cudLn3ngqi
4. RSUs (Restricted Stock Units)
A common form of equity compensation for publicly traded companies and Big Tech. One of the easier types of equity to understand: https://t.co/a5xU1H9IHP
5. Double-trigger RSUs. Typically RSUs for pre-IPO companies. I got these at Uber.
6. ESPP: a (typically) amazing employee perk at publicly traded companies. There's always risk, but this plan can typically offer good upsides.
7. Phantom shares. An interesting setup similar to RSUs... but you don't own stocks. Not frequent, but e.g. Adyen goes with this plan.
