Unlike other choices, choosing the core framework determines strategic factors like the development style and how likely the team is to hit a wall. We believe that framework popularity is a supreme consideration and put our focus on the top 4 most popular frameworks in terms of downloads and GitHub stars. The text below outlines the pros and cons of each framework and how to match a framework to the right application type
express.js
Pros: Unmatched popularity; gigantic eco-system of extensions and middleware; simple to learn and use; familiar to almost every Node.js developer; tons of community articles and videos are based on express
Cons: Covers a small subset of a typical application needs - merely a web server that invokes the app function per URL. Choosing express means leaving a handful of app concerns uncovered; outdated mechanics - no native support for async-await; barely maintained and updated; Slower than others
Nest.js
Pros: More batteries than any other option - covers many application concern including message queues, scheduled jobs and more; OOP-style is an advantage for teams who appreciate this design style; awesome docs; well-maintained; high popularity with a vibrant community
Cons: High-level abstractions that cloud built-in Node.js conventions; The inclusion of many features, heavy usage of TypeScript and reference to sophisticated patterns might push teams for increased complexity; Steeper learning curve due to a handful of unique narratives (e.g., interceptors, guards, modules, and more); Highly opinionated
Fastify
Pros: Relatively simple and lean; mostly based on Node.js/JavaScript standards; relatively shallow learning curve; with its official plugins cover many application concerns though not as rich as Nest.js;
Cons: Younger than others and not as popular yet; smaller eco-system compared to express and Nest.js
Koa
Pros: When compared with express: it's Simpler and nimbler; modern API with async/await support; better performance
Cons: Covers a small subset of a typical application needs - leaves a handful of app concerns uncovered; Not as popular as express and Nest.js
Prefer express.js when - having an experienced architect onboard and in a need to control the fine-grained pieces of the puzzle. In this circumstances, Koa is also a solid option with a more modern API than express but a much smaller eco-system
Prefer Fastify when - The app consists of reasonably-sized components/Microservices (i.e., not a huge monolith); for teams who have solid JavaScript & Node.js knowledge; when sticking to Node.js narratives and spirit is desirable
Prefer Nest.js when - It's desirable to design and code in OOP style; when the team is highly experienced with Java/Spring/Angular or similar; for large size app that can't be broken down (i.e. monolith) to autonomous component; for a team that lacks fundamental JavaScript/Node.js skills (not exclusively, this yet another consideration); when the decision-making overhead should be minimized; when the time to the first delivery is a critical factor