It is possible, the condition is a bit poorly named. The video of the talk by Russell Barkley that is linked elsewhere is a good primer https://www.youtube.com/watch?v=YSfCdBBqNXY). People with ADHD can have episodes of hyper focus. However this is a bit a misnomer, it's called Perseveration and is not really a good thing, and has more to do with one's inability to task switch (https://en.wikipedia.org/wiki/Perseveration). However it also allows you to completely zone into a code base or a problem. The problem is you don't really have much control over what will catch your attention. But of course you can develop quite some deep technical expertise this way.

Now, that said, there is a new movie, Everything Everywhere All At Once, and if you take this title as a stand in for ADHD, maybe you can see that while this way of living can be overwhelming it also allows you to have a pretty good overview over systems and how their components interacts very fast. I think that's what many ADHD'ers are actually very good at, grokking code bases or the gist of things very quickly. Systems thinking in general. Also quick recall / association chains...

Also, on average, the higher your IQ, the later in your life your ADHD diagnosis will be (see this video on adult ADHD https://www.youtube.com/watch?v=dVDhYtQkuO8). Your other abilities can compensate somewhat for your ADHD. Also of course when battling this condition you will build many personal tools and habits that neuro-typical people will never have to do, so in that sense you also might have a leg up in certain situations.

I'd say professionally the biggest problem is not so much on a technical level, but more on an emotional / impulse control level. ADHD'ers can come off as brash, speaking their mind freely, not being able to just put that comment in when it's better to shut up.

Attention-deficit hyperactivity disorder is poorly named. It does not necessarily imply an inability to focus. It's essentially a combination of impulsiveness and poor short-term memory.

A person with ADHD will have a tendency to get distracted from the task they're supposed to be working on, and will instead work on other things. That's not necessarily bad if those other tasks are important. Perhaps counter-intuitively, the lack of impulse control may even lead them to hyper-focus on a task... just maybe not the one they were assigned.

People without ADHD also get distracted, but they have the impulse control to better resist tempting distractions, and the memory to remember to return to their original task after unavoidable distractions.

My entire view of ADHD changed when I saw a video for parents of children with ADHD a few years back. This is one of my favourite HN comments of all time: https://news.ycombinator.com/item?id=17889156

ADHD is quite badly named imo. It's not so much a deficit of attention but a disregulation. If you are interested in something then you can invoke an almost obsessive fixation on the task (hyperfocus I believe some people call it) which lends itself well to coding in certain conditions.

Sure. I've been diagnosed with very severe ADD and I've been programming since I was 8 (now 34), professionally since ~18. I took medication for ADD but have since stopped, as it basically caused me to sit for 9 hours and work with no breaks or food. I still have plenty of issues related to ADD, but I'm good at what I do all the same.

It has way bigger consequences outside of work for me. Things which you are very passionate about are easier to focus on than things you are not, regardless of AD(H)D.