While a Postmortem helps you see what went wrong after an event happens, a Premortem is where you imagine a future where you didn’t achieve your goals.

Visualising a big headline that reads “We Failed to Reach Our Goal” challenges you to think about ways in which things could go wrong. It helps highlight your biggest fears and proactively figure out steps for how to defuse them.

How a Premortem helped us get ready for Apple’s iOS 8 launch in four months flat

I’ll tell you a true story about my first Premortem. I’d just joined a company as the new CTO, and we had been invited to be featured in Apple’s iOS 8 launch in…


Image credits: You X Ventures — Unsplash

I’m an ill-disciplined person. My habit of reading books about habit-formation is stronger than any of the habits they’ve help me form.

Perhaps because of this, I’m interested in the idea of keystone habits — “a small and manageable shift or change that acts as a catalyst for success in many other areas of your life”. For example, sleep and exercise tend to have positive knock-on effects, and make it easier to keep to other habits.

What do you think is the single most effective keystone habit for a team, i.e. …


A couple of decades ago, to set up an online web service you’d have have to buy physical servers and colocate them somewhere. It took planning, effort, upfront capital, lead times and physical access.

Now, with three clicks of your mouse/heels, you can summon 20 cloud servers to answer your bidding instantly.

“There’s no place like AWS” (Image credit: Maria Marklove)

And just a few years ago, to set up a machine learning service, your data scientists would have to laboriously work through a morass of preprocessing, parameterisation and acceptance testing. It took planning, effort, lead times, salaries, datasets, computation, and a tolerance for risk.

What about now? Are…


Image credit: Pixabay

Our goal as programmers is to write small pieces of code that combine together to do something useful:

  • Each piece should be simple, so we can understand what it’s doing.
  • Each piece should minimise its dependencies on other pieces, so that you can make changes without everything else breaking.
  • The pieces should combine together flexibly so that you can build big programs out of them.

In other words, we want our code to be modular, so it’s simple and reusable. Pretty much everyone agrees on this as a goal. …


Image credits: Pixabay

I’ve been asked this question by a few highly competent Senior Data Scientists over the years. Even just asking the question is usually a good sign that they have a sense of the answer — a sense that the skills that make you a good Senior Data Scientist may not be the key skills for succeeding at the next level.

To answer this question, let’s talk a little bit about what it actually means to become more senior as a data scientist.

The core idea is that as you get more senior, your area of responsibility grows. So, a Junior…


From Part 1, you have a sense of what data you need to protect and how to assess risk. Part 2 discussed documentation requirements.

The Security Rule

In this section, we’ll focus on some of the HIPAA Security Rule requirements. You know, the nitty-gritty/infrastructural work you knew you’d need to do: encryption, banning passwords on post-its, locks on filing cabinets, etc.

Perhaps the most striking thing to me about HIPAA is how little it specifically mandates. It doesn’t say that you must use a particular algorithm to encrypt your hard disks with, or how many locks you need on your door. It divides…


From Part 1, you have a sense of what counts as Protected Health Information (PHI) and how to conduct a Risk Assessment to understand the risks to those data.

So you’ve already had your first taste of HIPAA’s documentation needs. Document it, or it didn’t happen!

Here’s how we break down our documentation:

  • Risk Assessment spreadsheet to determine what you should be worrying most about — discussed in Part 1.
  • Policy docs — these describe and dictate everything about how you’ll operate to abide by HIPAA’s rules. There’s a great deal to be said about this — you could start…


I can still fondly remember when I thought a HIPAA was the most dangerous animal in Africa. Then I learned it only has one ‘P’, which might as well stand for ‘paperwork’. Two years on, I see HIPAA as a well-crafted and pragmatic set of regulations that have helped us build up our data security and privacy approach. And though it’s my job to continue worrying, I now worry in a much more structured way.

From http://www.hippoprint.co.uk/quality_next_day_printer.html

We’re a software startup that helps people with sleep and mental health problems. …


Wikis aren’t empty, like the term ‘cyberspace’ sounds, nor filled with clean, glowing lines, nor grungy and neuromantic.

Wikis are a communal garden, where anyone can graze, and anything can grow. Just like a communal garden, one fears vandalism and internal strife, and one battles against an idealism that can spill into self-righteousness. On the plus side, the devilish generativity and the pleasure of just wandering around and gazing at the flowers tended by many hands is a huge pleasure.

But the biggest problem with wikis is that, perhaps also like gardening, they need regular tending otherwise they turn into a jungle, and they need a structuring vision to decide what should be where.


Within a few steps of getting off the plane at Newark on my way to Princeton, I could feel myself traveling back in time as well as in space.

I spent 7 years in Princeton as a research assistant and PhD student, thinking about human forgetting and new computational approaches to studying the brain.

I’ve been back once or twice in the 6 years since I graduated, but a lot has changed. For starters, I’m married now and accompanied by my wife. I manage the engineering team at Big Health, rather than working as a researcher in a lab. I…

Greg Detre

Advisor and coach. Former Chief Data Scientist at Channel 4, co-founder of Memrise, CTO of Big Health. www.makingdatamistakes.com

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