October 18, 2017
12 Things a Professional Computer Programmer Needs to LearnThe last few years has seen an explosion of great learning resources for people interesting in getting into computer programming.
Nothing could be further from the truth, though. Programming languages are just one small aspect of writing software as a professional (albeit a crucial one).
When learners ask me "What else do I need to know how to do?", I'm typically unprepared to answer. Unhelpfully, I might just say "Loads!"
Here, I'm going to attempt to structure some thoughts on this.
2. Learn to use Version Control. Version Control Systems (VCSs) are seatbelts for programmers. If your code has a nasty accident, you want to be able to easily go back to a versin of it that worked. And most professional developers collaborate with other developers on the same source code, so to do it for a living you'll want to know how to use VCSs like Git and Mercurial to effectively manage collaborating without tripping over each other.
3. Learn to work with customers. Typically, when we're learning to code, we tackle our own projects, so - in essence - we are the customer. It gets a bit more complicated when we're creating software for someone else. We need to get a clear understanding of their requirements, and so it's important to learn some simple techniques for exploring and capturing those requirements. Look into use cases and user stories to get you started. Then learn about Specification by Example.
4. Learn to test software. There's more to making sure our code works than running the application and randomly clicking buttons. You'll need to understand how to turn requirement specifications into structured test scripts that really give the code a proper, in-depth workout. How do make sure every requirement is satisfied? How do make sure every line of code is put through its paces? How do we identify combinations of inputs that the code can't handle?
5. Learn to write automated tests. Automated tests are commonly used in Specification by Example to really nail down exactly what the customer wants. They are also crucial to maintaining our code as it grows. Without a decent set of fast-running automated tests, changing code becomes a very risky and expensive business. We're likely to break it and not find out for a long time. Learn how to write automated unit tests for your code, and how to automate other kinds of tests (like system tests that check the whole thing through the user interface or API, and integration tests that check system components work together).
6. Learn to write code that's easy to change. On average, software costs 7-10x as much to maintain over its lifetime as it did to write in the first place. And if there's one thing we've learned from 70 years of writing software, it's that it'll need to change. But, even though we call it "software" - as opposed to "hardware" - because it's easier to change than the design of, say, a printed circuit board, it can still be pretty hard to change code without breaking it. You'll need to learn what kind of things we can do in code tend to make it harder to change and easier to break, and how to avoid doing them. Learn about writing code that's easy to read. Learn about simple design. Learn how to avoid writing "spaghetti code", where the logic gets complicated and tangled. Learn how to shield modules in your code from knowing too much about each other, creating a dense web of dependencies in which even the smallest changes can have catastrophic impact. Learn how to use abstractions to make it easier to swap out different parts of the code when they need to be replaced or extended.
7. Learn to improve the code without breaking it. We call this skill "refactoring", and it's really, really important. Good programmers can write code that works. Great programmers can improve the code - to make it easier to understand and easier to change - in ways that ensure it still works. A function getting too complicated to understand? Refactor it into smaller functions. A module doing too much? Refactor it into multiple modules that do one job. This skill is very closely connected to #5 and #6. You need to know bad code when you see it, and know how to make it better. And you need to be able to re-test the code quickly to make sure you haven't broken anything. Automated Tests + Design Smarts + Refactoring form a Golden Circle for code that works today and can be easily changed tomorrow to meet new customer requirements.
8. Learn to automate donkeywork like building and deploying the software. Good software developers don't manually copy and paste files to production servers, run database scripts, and all of that repetitive stuff, when they want to create test or production builds of their systems and deploy them to a live environment. They program computers to do it. Learn how to automate builds, to do Continuous Integration, and automate your deployments, so that whole delivery process can become as easy and as frictionless as possible.
9. Learn about software architecture. Is your application a mobile app? A website? A Cloud service? Does it need huge amounts of data to be stored? Does it need to be super-secure? Will some features be used by millions of users every day? Will it have a GUI? An API? Is the data really sensitive (e.g., medical records)? We have 7 decades of knowledge - accumulated through trial and error - about how to design software and systems. We have principles for software architecture and the different qualities we might need our software to have: availability, speed, scalability, security, and many more. And there are hundreds of architectural patterns we can learn about that encapsulate much of this knowledge.
10. Learn to manage your time (and yourself). You might enjoy the occasional late night working on your own projects as a beginner, but a professional programmer's in this for lomg haul. So you need to learn to work at a sustainable pace, and to prioritise effectively so that the important stuff gets done. You need to learn what kinds of environments you work best in, and how to change your working environment to maximise your productive time. For example, I tend to work best in the morning, so I like to get an early start. And I rarely spend more than 7-8 hours in a day programming. Learn to manage your time and get the best out of yourself, and to avoid burning out. Work smarter, not harder, and pace yourself. Writing software's a marathon, not a sprint.
11. Learn to collaborate effectively. Typically, writing software is a team sport. Teams that work well together get more done. I've seen teams made up of programmers who are all individually great, but who couldn't work together. They couldn't make decisions, or reach a consensus, and stuff didn't get done because they were too busy arguing and treading on each others' toes. And I've seen teams where everyone was individually technically average, but as a single unit they absolutely shone. Arguably, this is the hardest skill, and the one that takes the longest to master. You may think code's hard. But people are way harder. Much has been written about managing software teams over the decades, but one author I highly recommend is Tom DeMarco (author of "Peopleware"). In practice, this is something you can really only learn from lots and lots of experience. And increasingly important is your ability to work well with diverse teams. The days when computer programming was predominanly a pursuit for western, white, middle class heterosexual men are thankfully changing. If you're one of those people who thinks "girls can't code", or that people from third-world countries are probably not as educated as you, or that people with disabilties probably aren't as smart, then I heartily recommend a different career.
12. Learn to learn. For computer programmers, there's 70 years of learning to catch up on, and a technology landscape that's constantly evolving. This is not a profession where you can let the grass grow under your feet. People with busy lives and limited time have to be good at making the most of their learning opportunities. If you thought you'd learned to learn at college... oh boy, are you in for shock? So many professional programmers I know said they learned more in the first 6 months doing it for a living than they did in 3-4 years of full-time study. But this is one of the reasons I love this job. It never gets boring, and there's always something more to learn. But I've had to work hard to improve how I learn over the years. So will you. Hopefully, the more you learn, the clearer the gaps that need filling will become.
So, there are my twelve things I think you need to learn to be a professional computer programmer. Agree? What would be on your list? You can tweet your thoughts to @jasongorman.
Posted 3 months, 4 days ago on October 18, 2017