Way back in 2004, I met the first senior dev of my then short career. We'll call him Matthew. On my first day working in-office as a contractor, he sat with me and rather eloquently explained how their JavaScript application worked and the tasks to be done. There was no Git. Hell, I don't remember there being SVN. I would be fixing bugs and adding small/medium features to a complex pile of pre-framework, grass fed, vanilla JavaScript.

Although I've mostly forgotten the inner workings of that web app, I never forgot Matthew and the way he was. While explaining the app to me, he carefully detailed his approach, the patterns he used when building it, and the mental models I should construct in order to best understand it. When asked at various checkpoints if I understood what he was saying, I nodded along apprehensively, afraid to ask too many questions and reveal my misunderstandings. Matthew sensed my uncertainty and told me it was okay to be confused, and then proceeded explaining several of the hardest concepts in different ways. By the time he left my desk, I was brimming with excitement, armed with knowledge and a powerful urge to impress.

The contract only lasted 2 months, but was successful. On my last day, I left the building with a new awareness of what a developer could be to other developers. Before working for Matthew, I'd worked on several handfulls of similar contract jobs, but never considered that my own demeanor and attitude towards other devs really mattered. Everything to that point in my career had been about the work, the quality and cleanliness of the code and meeting the deadline.

I began to realize that this was only part of the story. Being a strong solo contributor could only get you so far. But talented coders who also took a genuine interest in helping others contribute their best work were the actual 10x developers. You were multiplying the productivity of other people who might multiply the productivity of other people. The senior dev could be more than a sparkplug—he could be a power generator.

Not a Jedi Yet

If Hollywood had written my script, my next job after meeting Matthew would have thrust me into a leadership role where I'd flourish and reach my maximum potential. This is not how life tends to happen. Until the early 2010s, I stayed focused on contract work, learning as much as I could and writing a lot of JavaScript. Despite being 10 years into the game, I still did not feel like a senior developer. Rather, I would become more of a specialist on the front-end—especially in CSS—and found that most devs I met did not enjoy that sort of work. Hence, this became my niche for a while.

Real Senior Dev Experience

In 2013, a unique opportunity presented itself. My engineering position had an optional leadership role associated with it. If accepted (which I did), I would build a small web team and train them on standards. Everything I'd learned to that point of my career could be shared with others. I scoured resumés and began interviewing every day. After a month or so, I hired six individuals. Some of them failed our coding assessment, but had the sort of personality I wanted on the team. One applicant was so upset about failing the assessment, he rewrote his solution three different ways and emailed me the code at midnight that same day. That's the kind of person I wanted on my team.

After only a month or so, I found myself reviewing others' work and offering advice on how different UI challenges should be approached. I wrote reusable components and trained 40 developers in the still nascent SCSS. I (and many others) burned out after about a year at that place, since the job demanded 60+ hour weeks. When you're young with a chip on your shoulder, those kind of hours are easy to accept, but they take their toll on mental and physical health. I saw one guy go from lean to fat in only six months time. Some devs on my team confided in me about their troubled relationships at home and how the complete lack of work/life balance was destroying their lives. The company responded by offering in-office laundry service and catered lunches.

2026 --ff

20 years later, physical offices feel like outdated dungeons. Every interaction with a co-worker takes place on a screen. Part of the magic I recall when learning from Matthew occurred in person, on a whiteboard, or while walking together for coffee. But things have improved in some ways. Today, if I get stuck on a problem, I ask the LLM for help, and with no compunction about wasting its time or breaking its concentration. Heck, the LLM makes learning so easy and stress free, it killed Stack Overflow.

But let's be clear about why Stack Overflow died. It's not because you'll get a better answer from an LLM, but rather that you'll never be disciplined or shamed for how, when or where your question is asked. You can misspell a word or phrase your question awkwardly and the LLM will respond no matter what, often with an answer that is good enough that you can move forward. Is this better than what we had before? It's subjective, of course, and the answer is yours to know.

Given all of this, what does a good senior developer in 2026 look like?

Awareness of AI tools across the team

Matthew 2.0 writes skills and workflows which improve the product, but not just for himself. He finds ways of sharing his knowledge with the team, and ensuring they, too, can use the same skills with writing code with an LLM. This creates continuity across all code entering the product.

Knowledge of integrations between agents and external systems

Matthew 2.0 understands that work can continue from a Telegram prompt while a developer is in line at the grocery store. Work can survive and thrive beyond the barrier of a desk. Agents can trigger workflows from a ping in Slack, not simply from the terminal. Matthew 2.0 is happy to help get others up and running with these new integrations, making developers across the team more productive and self-sufficient.

Opinionated but still open-minded

I've seen developers who are looking for something far beyond the coding world. They're seeking a perfect order and a system that will never fail them. It seems at times to be something of a religious nature. Although the coding world can't give them this, they won't stop trying to find it and will often declare some new workflow "god tier" and even shame others for not following in their footsteps.

Matthew 2.0 understands that we're all building sandcastles. Everything we've ever written and will ever write will be replaced and forgotten. The best developer would rather be remembered for how he helped and empowered others—not the code he wrote which made the page load a second faster than before. Matthew 2.0 has mastered perspective, and a strong perspective allows bend in a stalwart but still tractable approach.