People: The API User’s Guide

A keynote I gave at PyCon 2023.

This is the overall gist: the stereotype of engineers is that we are bad at people interactions because we are engineers, but my claim is that we can use our engineering skills to improve. We can be good at people interactions because we are engineers.

Here’s the video, or you can read the text below on this page.

This text here is not literally what I said on stage. It’s what I had typed out ahead of time while writing the talk. During the talk I ad-libbed and riffed, but the ideas here are the same, just a bit more succinct.

Many slides have transitions that aren’t apparent from the images here, but you can click into an image to see the actual presentation from that point.

The cartoons are by my freelance illustrator son Ben Batchelder: hire him!

BTW, I have a blog post about the process and experience of preparing and delivering the keynote: PyCon 2023 keynote.

•    •    •

Ned Batchelder
What to talk about?

I wondered what I should talk about today.


I work at edX, a 2U company, on the Open edX project. It’s a large Python and Django project powering and thousands of other online learning sites around the world. I could talk about online education, or million-line monoliths, or producing open source inside a for-profit company.


I’ve been maintaining for a long time. This is Sleepy Snake, the project’s mascot. I could talk about working on a large widely used open source side project.


I’m an organizer of Boston Python. I could talk about running community groups, or what we did to keep it going though the pandemic.


I’ve been blogging for more than 20 years, since before the first PyCon. I could talk about what it’s like to put my hot takes out on the internet for abuse.


I’m often in online communities like IRC, Slack, or Discord, pictured here.

I could talk about teaching Python basics, or how these communities are the same and different. For example, on the public Python Discord server, it means being in a space with people one-third my age who constantly ask me if that’s really me in my profile picture.

But instead of any of those specific topics, I wanted to step back and discuss something that underpins all of these things.

High-uncertainty componentsin complex systems

High-uncertainty components in complex systems.

OK, that’s not the real title. It’s fake high-tech jargon designed to appeal to all you techies. I do want to talk about high-uncertainty components and how they interact, but there’s a simpler word for the ones I want to talk about: People.

I want to talk about how we interact with each other. As engineers, we can fall into the trap of approaching people the way we approach inanimate components we use. It can go badly, because people don’t work like electronics or software.

We can tend to do this for a few reasons: either, we expect everything to work like engineering components, or we don’t think we’re good at dealing with people, or we don’t think it’s important to deal well with people.

Soft skills

Sometimes we call these “soft” skills. Some people frown on this term, because it makes them seem lesser, simple things that anyone can do, or not as important somehow.

I don’t think of soft skills as lesser. The only reason some people think of them as lesser is because as a field, we value the hard edges of hard skills. Rigid rules and quantitative measures. Your Python syntax is either right or it’s wrong.

Soft skills have none of those rules and guardrails. They’re all squishy and vague and subjective. There’s no linter for Slack conversations. That’s exactly what makes them difficult, especially for quantitative people like us.

If it helps, you can think of this as emotional intelligence, which has that hard-sounding word “intelligence” in it.

People are terrible

Let’s face it: people are terrible. But only if you think they are going to work like technical components. They don’t work that way.

Let’s consider people through the lens of some engineering qualities. What are the characteristics we value about components in systems, and how do people stack up?


First off, people are not standardized. Everyone is different, sometimes in small ways, sometimes in big ways. What they know, how they speak, how they work, what they like, what they don’t like, and so on.

You can’t treat people as interchangeable components. What works for one person can be really bad for another. You have to adjust for their differences.

No docs

To make matters worse, people don’t come with documentation. When you meet someone new, they don’t hand you a manual explaining how they are different than someone else. Sometimes there’s a bio, or a LinkedIn profile, but that rarely tells you the really important things to work smoothly with someone.


Because everyone is different, and they don’t come with instructions, people are unpredictable. Just because they know one thing, you might not be able to guess that they know another thing. If they have an opinion on a particular topic, it doesn’t mean you can predict how they will feel about another topic. And they may change from day to day.

Hidden state

One of the things that makes people unpredictable is that they have a lot going on inside, very little of which you can see. In software design we talk about avoiding mutable global data because it can have far-reaching effects that are hard to reason about.

People are full of mutable globals, and you can’t see them. Maybe they didn’t like their breakfast, or they’re worried about a sick child. Maybe they just had great news from a friend. None of that is apparent, but it can change how they behave.

This guy has a lot on his mind. Notice Sleepy Snake is in there: he’s thinking about, so I can relate.


Because of that hidden state, responses can be non-linear. You might ask a question and get a good response. But ask a little more, and you’ve pushed them past their stress threshold, and a situation can blow up. The response is disproportionate because it involved hidden state you can’t see. Maybe your question reminded them of a bad person they dealt with years ago. You can’t know that. All you see is that you did something small and got back something huge.

Unclear error messages

Finally, when something does go wrong, you don’t always get good information about why. People don’t want to talk about all of their hidden state. It’s considered unprofessional. We can think of it as baggage. Maybe they don’t like that they reacted badly, and they want to move past it.

You know the situation: someone is upset, and you ask them what’s wrong, and they reply, “Nothing.” That’s a terrible error message! We want our systems to tell us specifically what is wrong when something is wrong. People don’t do that.

So you don’t always get an understanding about what happened, or how to avoid it in the future.

Why bother?

OK, if people are so terrible, why should we bother with them?

First of all, you have no choice. No matter how introverted you are, how much you work on your own, you are going to be dealing with people. You’ll have collaborators, a boss, your software will have users, and so on. People are all around you, and you will be talking to them.

People are fantastic

More importantly, people are fantastic.

They are flexible, and creative. They can reflect your energy back to you. For most of our work, they are the very reason we do the work.

Maybe this is the wrong place to be making this point. After all, you have travelled here to be with people. You understand the power of those interactions.

As I said, you don’t have a choice whether to deal with people. But you can choose how well you do it. As engineers, we can think about our interactions and improve.

It all starts with talking to people.

How to talk to people

Let’s get into how to talk to people.

Except since you are engineers, you might not naturally want to talk to people, so let’s think of it differently: People, the API User’s Guide.

We can look at how talking to people works and what happens in those interactions.

BTW, when I say talking, I mean any method of communicating with someone. It could be talking, it could be typing in Slack, it could be an email. The same basics apply.

And just to be clear: I am not a psychologist. I’m an engineer who has spent years reverse-engineering people and debugging interactions. I’ve read the tracebacks of lots of discussions.

I’ve learned things the hard way. And I still don’t always get it right! There are definitely people here today that I have had conflicts with. I am sorry for that. And there will be conflicts and miscommunications in the future. It happens. The important thing is to learn and try to do better.

None of this is easy. But it is important.

Information + Sentiment

Here’s an important central idea: every message you send to a person will be heard as having two parts: information and sentiment.

For a lot of what we say to each other, the information is the important part. I’m trying to tell you something, or you are asking me for something, or whatever. This is the part engineers find it easy to focus on: what are the facts, the request, and so on.

But every message also carries a sentiment, whether you want it to or not. Sentiment might not be the right word: maybe emotion is better, or mood or the energy of a message. Underestimating this is where we can get into trouble.

Usually, information is the explicit part of the message: most of the words are the hard-edged facts we want to convey. They are easy to see. The sentiment is usually much more subtle.


Sentiment and emotion are complex topics, of course, so let’s simplify them for our purposes. At a really really basic level, I think of every message as being either a Yes or a No, of varying intensity.

Words can welcome us in, or they can push us away. They can give us a good feeling or a bad feeling.

People are social emotional creatures. They need to understand how you feel about them. You’ve heard of “sentiment analysis” tools that read tweets, and try to figure out how people are feeling about Nike sneakers? People around you are doing that all the time, but they’re doing it to your messages, to figure out how you feel about them.

Defaulted sentiment

The problem is, sentiment can be subtle enough that the recipient infers or defaults it. If the sentiment in your message isn’t clear enough, the recipient will fill it in for you, and not always in the way you want.

How is missing sentiment filled in?

First, your history together will be the biggest source of fill-in material. If you’re friends with someone, and have a long history of positive interactions, then messages will be mostly assumed to be positive. Or, if you have a long history of conflict, that history will negatively color every interaction.

If your history is short or non-existent, then the sentiment might depend on perceived similarity. The recipient will judge how similar you two seem to be. The more similar, the more likely your message will be considered positive.

What do I mean by similar? Who knows!? It could be age, gender, haircut, clothing style, taste in music, laptop stickers, it could be anything at all. As an example, we are all here at PyCon, and that makes us all similar in a certain way. We are members of a community. The more you have in common, the more likely your ambiguous message will be welcomed.

If you have no history, and you don’t seem that similar, then you might as well assume that the defaulted sentiment will be “Bad.” Maybe it won’t be, but you are at the mercy of all of that hidden state we talked about.

Finally, that hidden state we talked about will come into play. It will color how your message is received, without you even knowing it.

Keep in mind: this is not conscious on the listener’s part. They aren’t trying to assume the worst about you. They are getting words from you and trying to piece together both the information and the sentiment. They want to hear you, but they are also trying to understand their place in a chaotic world. They’re doing what people do.


Maybe this is obvious, but: if your recipient feels negative energy in your message, they are not going to listen to you.

This is why the sentiment is important: it determines how the receiver will handle the information in your message.


Just to make this concrete for you technical people: here is some pseudo-code. It’s not the real code!

Can't we all just...

At this point, the engineer in you might be saying, can’t we all just stick to the facts? Why do we have to mix emotion into it? Why can’t we stay at the nice objective information level?

Yeah, sorry, you can’t. As flexible and amazing as people are, there are things we can’t change about them. They need to know how they are doing. Without clear signals, they will fill in the gaps, and not necssarily in the way that you want them to.

We aren’t going to replace people with robots, so you need to work on the sentiment parts of your messages just as much as the information parts.


Oh, and by the way...

I don’t want to shock anyone, but each and every one of you is also a person. That means at the same time you are struggling to get your messages through to other people, dealing with all of their weirdnesses and hidden state, they are also trying to talk to you, and your complexity is getting in the way of you hearing their messages.

Improve your chances

So, what can we do to improve our chances? We’re saying something to get a message across, but there’s this sentiment minefield that can get in the way.

I’ll talk about five things to do: say yes; use more words; choose your words carefully; be humble; and be explicit.

I’ll demonstrate with some chats. These are short and stylized but will demonstrate the basics.

First tip: say yes. I don’t mean literally, “yes.” I mean that you should try to word your messages so that they fall on the yes side of the spectrum instead of the no side. Make them welcoming.

Don't say no

Here’s an extreme example.

The speaker on the right is correct: that is not an array, it’s a list. On a factual level, they are even half-providing some useful information: calling that an array will get in the way of learning about lists in Python. But it’s not helpful, because it’s pushing the asker away.

Say yes

Instead, they could have answered the question, providing the answer the asker is looking for, and sneaking in the correct term along the way.

BTW, a lot of my examples are people asking for help, but the principles are the same for any interactions.

Not enough words

This is a classic example of an ambiguous message. The speaker on the right might be genuinely interested in the reasons for using THING. They might be open to a deep and helpful conversation.

But they’ve started with an ambiguous message that can sound like criticism.

I’m very familiar with this one, because I like to ask why, and I can see how it comes off sounding like “You shouldn’t use THING.”

Good: Use more words

Here the right speaker uses more words, including explicit agreement with the left speakers’s experience. These are Yeses that put them on the same side of the problem. The asker feels a shared experience with the helper that helps them build a bond and then work together on the problem.

Choose your words

Here the left hand is telling us something that is clearly wrong. But “that’s wrong” is too blunt and doesn’t welcome further discussion. Saying, “that doesn’t sound right” instead opens up a possibility for investigating.

There are lots of reasons why their program might be producing that result. “Doesn’t sound right” includes some doubt on the helper’s part. This is a small example of being humble. They are less certain, open to discovering something unexpected. It puts them both on a more level field.

Be humble

Here the asker is to be honest, talking nonsense. They don’t know what they are saying. But “you aren’t being clear” is an accusation, and puts all the blame on the asker. “I don’t understand” carries the same information, that the situation is unclear, but the helper is taking some of the fault. They are lowering themself, which again levels the field and helps put the asker at ease.

In general, it can help to make yourself the subject of the sentence. “You” sentences can seem aggressive. “I” sentences are more humble, and more honest. You can’t know another person’s state of mind, but you can know yours.

Being humble and letting go of some hard-earned status can be difficult. But it’s good to be less certain, and to open yourself to possibilities you haven’t anticipated. It allows in others, and makes you more similar to them, which makes it easier to communicate well with them.

Ask questions instead of making absolute statements. I don’t want to get into stereotypical gender roles, but here’s a simple rule of thumb: whatever the opposite of mansplaining is, do that.

Be explicit

One obvious way to be sure your sentiment is understood is to be very direct with it. When you use more words, you can say things that are just sentiment.

One strategy is to always start and end with a Yes, even if you need to have more difficult messages in the middle. Think of it as a Yes Sandwich.


I’m sure all of this seems hopelessly simple. You might think, all you’re saying is be nice, and think of the other person. Yes, that’s what I’m saying: be nice, and think of the other person. It’s the kind of thing they teach in kindergarten. I’m standing here telling you this, but maybe this little guy could have done it instead. That’s me at about 10% of my current age. When we were young, we were taught to be nice and think of the other person.

Earlier I mentioned soft skills as something anyone could do. They’re something anyone can do, and everyone should do. We all were taught these things at a young age.

Then over time we start to believe that we don’t have to do that anymore, or that other people can somehow take care of themselves no matter what we say. But we’re all just people trying to make sense of the chaotic world around us.

The better you can deliver your messages, the better it’s going to go. Be nice. Think of the other person.


We’ve talked a lot about sentiment, let’s talk about information. We’ll get into some technology.


In the mid 1400’s, Gutenberg developed a process for producing printed pages using movable type.

I know this is not the technology you thought I was going to talk about. But it’s an interest of mine, and there’s a point at the end. It won’t take long, stick with me.


To produce printed pages, small chunks of metal called type are arranged in a form, placed in a press, inked, and pressed to a piece of paper.


Gutenberg’s big advance was how to produce the type. Printers need many uniform pieces of type to produce pages with consistent designs.

The process started by carving a reverse-image letter at actual size into the end of steel bar called a punch.

The punch is then driven into a bronze plate called a matrix. The matrix is put into the bottom of the mold, molten metal is poured repeatedly into the mold, and the result is many pieces of uniform type.


Punchcutting was a difficult job. The punchcutter worked in metal at tiny sizes, carving reversed letters in steel.

How would a punchcutter assess their progress? It’s too hard to use the punch to make a matrix, use the matrix in a mold to make some type, put the type in a press, ink it, and make a page. Even then, it was an ordeal to get your work into production!

The punchcutter had a simpler way: use a candle flame to coat the punch with soot, then press the punch onto a piece of paper. The resulting image reads correctly with a good black impression, and cleans up quickly.

We use the same term they did for our quick checks of progress: a smoke test. I know: there are other etymologies for smoke test, but I think this is the right one. Fight me!


OK, now we have lots of type, how do we make pages? A person called a typesetter picks pieces of type and places them in order, building columns of text line by line.

They stand at a work station that looked like this: two wooden trays hold type in specific compartments.


The trays were arranged like this. The common small letters are in the bottom tray, and the less-needed capital letters are in the top tray.

They aren’t called bottom tray and top tray though. The trays are called cases. This is the lower case, and this is the upper case, words that to this day everyone uses to describe these letters. Remember: a case-insensitive regex is one that doesn’t care whether the chunks of metal come from the bottom wooden tray, or the top wooden tray.

Let’s look at the layout of the lower case: the most common letters are in larger compartments near the center of the case, with less common letters in progressively smaller compartments farther out. It’s an ergonomic layout that takes letter frequency into account.

The upper case is different: the compartments are all the same size, laid out alphabetically A to Z, except J and U are at the end.

Wait, what!?

How are you feeling about this? Curious? Confused? Annoyed? Angry?

I wanted to talk about Gutenberg because I figured it would be new to most of you. I wanted you to be the newcomer, to have a bunch of new things thrown at you, then to encounter something so odd that it seems almost intentionally perverse. It’s so easy to see how it could have been better. Why are J and U at the end? Why did they do this to us?

In our technical conversations, there are moments like this all the time. It’s hard to take in new information. It’s not clear which parts will be important later. Maybe that smoke test thing was just a nerd going on too long about something that fascinates him!

Details get intricate. Reasons can be obscure, or obscured. When they are new to us, we have to accept them and deal with them, regardless of why they are the way they are.

Just to close the loop on this: the reason J and U are at the end is that J and U weren’t considered distinct letters in English until the mid-1600’s. Until then they were just stylistic variants of I and V. The layout of the upper case had been established and in use for 200 years by the time J and U were added to it. So rather than disturb centuries of tradition, J and U were added at the end.

And J and U remain at the end to this day, more than 300 years later! If you visit a letterpress print shop today, you will see cases laid out like this. Next time you want to whine about backward compatibility or legacy systems, these printers want to have a word with you!

Python is also strange

As experts, it’s easy for us to get accustomed to our familiar strangenesses. We forget how odd they are. I’m not saying we should get rid of the strangenesses; for the most part, we can’t. But we can be understanding when others have difficulty with them.

Technology starts weird and gets weirder, we just have to live with that.

Last year, during his PyCon keynote, Łukasz Langa said, “if you don’t say controversial things in a keynote, are you really living your best life?” I don’t know, is this controversial?: lambda is a terrible keyword. It has no mnemonic value. Yes, there’s a reason and history behind it, but like J and U, the reason doesn’t help people understand it.


We love showing people this xkcd comic. Python is great, Python is amazing, people love it!


This one we don’t show off so much.

I’m not talking about packaging and installation, or even Python, in particular. I’m showing it as just one example of the kinds of complications and weirdnesses that we get used to. Some of you might look at this and say, “well sure, if you’re going to list every possibility of course it looks absurd.” But this is what people experience.

I’m not saying that Python is bad. It’s just that Python is technology, and technology starts weird and gets weirder. When we talk to each other, we are often talking about technology. Everything we do is weird and hard to get started with.

Python is easy!

Python is praised for being easy to start with, and it is, but only when you compare it to other programming languages. No programming language is actually easy. None of them is intuitive, all of them have traps.


I’m not just talking about beginners. We all have these problems. No matter how well you know Python, or your domain, you run into new things all the time. Python is used so widely across so many specialties, that two Python “experts” can have little in common.

You might know this first column of words. Do you know the second column? Do you know this third column? I don’t.

Experienced developers will face the same hurdles as beginners when they take a new job with a million-line monolith, or have to dive into an area they’ve never used before.

This boils down to missing context. You’ve got something that I don’t. That’s why you’re talking to me in the first place: to get a thought from your head into my head. That means I’m trying to learn something from you, and that can be hard.

When you talk to me, it’s hard to know what parts of your context I am missing. It’s hard even to realize what your own full context is. You’ve been so focused on your world, it’s easy to forget where the gaps are.

Take your time. Use more words. Be forgiving when it doesn’t work at first. Take some of the responsibility for those hiccups.


And I don’t mean to single out Python at all. All of software is full of oddities that have to be dealt with.

Again, I’m not talking about getting rid of these speed bumps, though the more we can clean up the better. I’m saying we need to empathize with people struggling with them. We have to provide more context. We have to know that when we are talking with each other, we are all struggling with knowledge gaps in some way.

Don't Contradict

If someone says Python is hard, it’s really easy for us to jump to Python’s defense, and also try to be encouraging and optimistic by saying “No, it’s easy.” But this sentence literally has the word “No” in it, and contradicts the user’s experience.

Saying “it’s one of the easier languages” is a positive statement, but still contradicts the user’s experience, and so can sound like a push back.


Here the asker said something about Python, but if you listen carefully, you can see that they are really talking about themself.

Better to use a truly welcoming answer.

And this isn’t just about beginners. I know a lot about Python, but if I take a new job at a big company, I’ll be the newb, dealing with an enormous unfamiliar codebase. My imposter syndrome will kick in, and I’ll be saying things equivalent to “Python is hard,” but with bigger words and longer sentences.


Most of my examples have been new learners asking questions, but the fact is that the weirdnesses never end. No matter how experienced someone is, they will continue to find themself in mystifying situations. You might be creating one of those mystifying situations. Listen to them. Hear how they are feeling.

As we like to say at Boston Python, “we are all beginners, some of us just have more practice.”

We are always encountering new technologies and unfamiliar situations. When you talk to someone, you often are bringing them into a new context. They will be overcoming their own confusion, trying to orient themselves.

Lifelong learning is a feature of our profession. It means that we are constantly off-balance and adjusting. It requires good communication, and can also make that communication difficult.


Layered on top of the inherent difficulties of talking to people are the realities of our current world: more and more of us are working remotely, interacting through screens instead of face-to-face. Or we’re online more and more with other communities.

Online channels like Slack or Discord encourage brevity: type a quick message, then switch to another window. But that’s the exact opposite of my advice to Use More Words. Sitting at our screens, it’s too easy to feel like an air-traffic controller trying to track multiple conversations at once, afraid that we’re missing something important.

In these online-centered interactions, often we’ve never met the other person face-to-face at all. That means we have little history with them, and we haven’t had much chance to find common ground.

We toss off quick messages, forgetting that we’re not interacting with a message, we’re talking to a person. Every one of those Slack channels is filled with people, and they’re all trying to figure out what you mean and how you feel about them.


An important step that is easy to overlook in our rush to deal with everything: why are we saying what we’re saying? What’s the goal of the message?

Are you trying to educate, or direct? At our worst moments, we can be trying to prove that we are right, at the expense of the actual goal. It’s fun to be an expert, but we shouldn’t wield it like a weapon.

Use those engineering skills: what was your goal? After you’ve said your piece, do a micro-retrospective: did it work? Did the message accomplish what you wanted? What could you have done better?


And on top of all of the technical difficulties, it comes back to interacting with people. The soft skills (that is, the difficult skills) are really important.

We engineers are good at many things, and we are good at learning new things. One of the things we can be good at is talking to each other. It’s a skill that can be improved. It requires focus and thought, but it is worth it.

People 101

I’ve only scratched the surface here. Like any complex topic, it gets very deep. Group dynamics, style differences, power balance, and lots of other factors will come into play. How do you decide who to talk to? What should you do if it just isn’t working? How do you stop talking to someone? What about malicious people? These are not easy questions. I don’t have all the answers.

What I hope I’ve done is convinced you that it’s important to do well, and that it’s a skill you can work on like any other.

But doing it well is something to keep working at.


Here’s something advice for the next few days.

After my first PyCon in 2007, I wrote a blog post summarizing the trip. It included this piece of advice: talk to people. Everyone here is friendly, and they are here to meet you. Don’t be shy. Talk to them!

What are we here for?

The writer Kurt Vonnegut asked his son Mark, who is also a writer, what are we here for, what’s our purpose? You know, the big question. Mark neatly answered and side-stepped the question by saying, “We are here to help each other get through this thing, whatever it is.”

I think that’s a great call to action: be good to each other. Listen to each other. Help each other.


Thank you for listening. Enjoy PyCon! Thank you very much. And thanks to my illustrators!