Definition
A framework is a reusable foundation of code, structure and conventions on which developers build applications. It provides the common parts every application needs, such as routing, data access, security and rendering, and defines how the pieces fit together. Instead of starting from a blank page, a developer starts from the framework and adds the parts specific to the business. Examples include React and Next.js for web interfaces, Django and Rails for backends, and LangChain for AI applications.
In a company, framework choices shape hiring, speed and maintenance for years. A popular framework means a large pool of developers, plentiful documentation and libraries, and long-term support. An obscure one means dependency on a few people. Frameworks also carry security updates, so keeping them current is part of operational hygiene. When a CTO says "we are on React and Node", they are describing the framework stack.
Frameworks have become more opinionated and complete, and AI coding tools work best with the most popular ones because they have seen the most examples. Agent frameworks for AI applications are a fast-evolving new category. The misconception is that frameworks lock you in. Well-chosen ones are the opposite: they let you move faster and replace people more easily, provided you choose mainstream options and keep them updated.
In practice
In the companies I run, we standardise on a small set of mainstream frameworks. It lets a developer move between products in days and lets AI coding tools generate correct code, because the patterns are everywhere in their training data.
Why it matters
Framework choices are 5-year decisions about hiring, speed and maintenance cost. Asking your technical team why they chose a framework, and how mainstream it is, is a fair governance question.
Frequently asked questions
- What is the difference between a framework and a library?
- A library is a collection of functions you call when you need them; you stay in control of the structure. A framework provides the structure and calls your code at the right moments; you fill in the specific parts. Frameworks impose conventions, which speeds development but requires following their way of doing things.
- Which framework should my company use?
- Prefer mainstream, well-maintained frameworks with large communities in the languages your team knows, such as React or Next.js for web frontends and Django, Rails, Spring or Node-based frameworks for backends. Popularity brings hiring pool, documentation, security updates and better AI tooling support.