What 65,000 developers say about their tech stack — and what it means for your project

When you're commissioning custom software, one of the first decisions is the technology stack. Most clients don't have a strong opinion — and that's fine, it's the developer's job to advise. But it helps to know what the wider industry is actually using, because the answer shapes hiring, maintenance cost, and how long the software will stay supportable. Once a year, Stack Overflow runs the largest open survey of working developers — more than 65,000 responses in 2024 — and publishes the raw data for free. It's the closest thing we have to a ground-truth picture of the industry. Here's what the 2024 results say, and what we take from them.

Languages: JavaScript still on top, Python close behind

JavaScript was the most-used programming language for the twelfth year in a row, used by roughly 62% of professional developers. Python came second at around 51%, driven by its dominance in data, machine learning, and scripting. TypeScript continued its steady climb into the top five — it's now used by close to 40% of professional developers and is the default choice for any new frontend project of reasonable size. The takeaway: if a developer is suggesting something exotic for the core of your system, ask why. The mainstream languages have the biggest pools of talent, the most libraries, and the deepest documentation.

Databases: PostgreSQL overtook MySQL

For the second year in a row, PostgreSQL was the most-used database in the survey, surpassing MySQL — which had held the top spot for over a decade. PostgreSQL was also voted the most-admired database, meaning the developers using it want to keep using it. For most new business applications, PostgreSQL is now the obvious default: it's open source, it scales further than most companies will ever need, and the hiring pool keeps growing.

Web frameworks: Node.js, React, and Next.js dominate

On the frontend, React remained the most-used web framework. Node.js, which the survey counts as a web technology, was used by around 40% of professional developers. Next.js — the React framework we use for most projects — sits in the top ten and is growing year over year. The cluster of JavaScript-based tooling is now so dominant that almost any custom web app you commission today will be built on some combination of these technologies.

What this means for your project

The reason these numbers matter to a non-technical client is risk. Software lasts years, and the cost of maintaining it depends almost entirely on whether you can find people to maintain it later. A system built in a niche language by one developer who then leaves becomes a liability the moment that person walks. A system built in mainstream technologies can be picked up by any competent agency or in-house hire.

• Ask your developer what percentage of their stack is in the top ten of the latest Stack Overflow survey. If most of it is, you're in good company.
• Be cautious about exotic frameworks chosen because they're 'modern' or 'elegant.' Modern often means 'small community and no one to hire.'
• Prefer PostgreSQL over MySQL or MongoDB unless you have a specific reason. It's now the safest default.
• If frontend is involved, expect to see React or a React-based framework. If you're being pitched something else, ask for the reasoning.
• The point isn't to follow trends — it's to avoid being stranded when someone leaves.

Trends are useful, fashion is dangerous

A survey like this is a snapshot, not a prescription. Every project has its own constraints — sometimes the right answer is the less popular tool. But for the typical custom software project, defaulting to what the industry is already using is usually the lowest-risk path. The data is free, public, and easy to check. Before you sign off on a tech stack, it's worth fifteen minutes of your time.

Source — Stack Overflow Annual Developer Survey 2024: https://survey.stackoverflow.co/2024/