I inhaled sharply as I got to the conference room. The night before, when I saw an invite for a meeting early in the morning with HR and my boss and a nondescript subject I knew exactly what was going to happen. 2008 had been a lousy year: the housing bubble, the subprime crisis, banks collapsing everywhere. I was about to lose my job, in the middle of one of the worst global recessions in history, after 11 years at Microsoft. I smiled weakly as I entered the room.

My “Microsoft Ship It” — every time you shipped a product, you’d get a little metal plate to stick on your award

I wanted to write this story for three main reasons.


“Hey Carlos, what are you doing this Friday?” I quickly glanced at my calendar. “Not much, what do you need?” The recruiter paused. “Got a current passport? Can you fly to Tel Aviv? We got a 5-star hotel on the waterfront for the whole week. And we’ll visit Jerusalem one day. Gig’s yours if you can be there in 48 hours.” I smiled, as I frantically searched for last-minute flights to Israel. Being a Bar Raiser at Amazon did have some perks.

Top Amazon AWS Bar Raiser, Q1 2020

If you’ve interviewed at Amazon, you’ve had a Bar Raiser. A Bar Raiser (“BR”) is a special interviewer…


I’ve been involved in various aspects of engineering and operational excellence in three large companies (Microsoft 1997–2009, Amazon 2009–2020, Google 2020-now). In those decades, I’ve seen three major paradigms in the relationship between developers and test engineers, depending on the dev:test ratio. Each paradigm shift forced me to evolve and think differently about how to be effective at my job. It both threatened the future of my role and offered new growth opportunities.

It all came down to leverage and force multiplication. My favorite analogy is pulleys, which change the magnitude of a force. With a single pulley, you have…


I’ve spent a good chunk of my professional life at Google, Amazon and Microsoft focusing on engineering productivity tooling and processes. I’m fascinated by how a little bit of toil incurred here and there by each engineer aggregates to millions of dollars of productivity lost for a large software company. And also, I’m fascinated by a simple tool’s ability to change culture at large. This is a story of how a crappy little tool I wrote ended up changing a lot of the culture around unit testing and particularly test coverage at Amazon.

Before I go too much further, the…


Amazon is extremely lean, pragmatic and disciplined. During my 11 years there (2009–2020) I always found inefficiencies to improve, but when I stepped out of the building and had to deal with my son’s elementary school staff (sorry, Edmonds Elementary…), or the bureaucracy of getting discharged after a hospital visit, or pretty much anything a government office ever does, it provided a more fair and balanced view of just how tight of a ship Amazon actually runs. But I have a problem: by nature, I’m extremely undisciplined!

Dates matter. I learned very early on that when a leader asked me…


July 16, 1991. There I was, staring in awe at that giant Pan Am jumbo sitting on the tarmac at Ezeiza International, with my jaw to the floor. I was 15 years old and I had never seen an airplane in my life. That airplane was going to take me to a new life in America! It was a cold, rainy, gloomy winter day in Buenos Aires, Argentina. Cue in melancholic tango music in the background.

This isn’t my picture (credit), but it looked like this! (Pan Am went out of business a long time ago!)

The night before, I said my goodbyes to my extended family (some of whom I would never see again) and took an overnight bus…


“You want to leave Amazon???” my wife asked, shocked, “but you love Amazon!” Yes, yes I did. I had come to Amazon 11 years ago, and I had grown up with the company, watching it go from 3k developers to 50k developers (and its stock from $40 to $3500!). I was productive. I was happy. This was home. Yet after much soul searching, I was about to leave everything and jump into the unknown. During a world-wide pandemic that was shutting down the world. Was I crazy? And as a Principal Engineer, which brings its own set of complications.

There’s…


Sand as far as the eye could see. Just miles from the border with Saudi Arabia. Here we were, spending the night in a tent in the middle of nowhere in the Jordanian desert. This is a story about how one crazy idea I had with some Amazon friends over coffee in 2014 ended up taking us on an unexpected 150,000 mile, 5 year journey around the globe: to Amman, London, Madrid, Gdańsk, Dublin, Bangalore, Hyderabad, Chennai, New Delhi, Tokyo, Beijing, San Francisco and Boston, changing company culture in the process.

5 years and 150,000 miles later…

“Never doubt that a small group of thoughtful committed…


Imagine this. You’ve been at Amazon for two years. You got past the bump of learning the culture and internal tooling, are finally productive and begin to pursue a promotion to Senior Engineer. Life is good. You are responsible for the engineering and operational excellence of a service that is critical path of amazon.com. Yet today, the busiest, most important shopping day of the year, your service is down, causing millions of dollars of loss. Every minute counts, and it’s on you. This is the event that will change your life.

For me, that day was a turning point in…

Carlos Arguelles

Hi! I'm a Senior Staff Engineer at Google. Prior to Google, I spent 11+ years at Amazon. And prior to Amazon, I spent 11+ years at Microsoft.

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