
Flask
ExpressJS
Django
Yii Framework
Bottle
Ruby on Rails
Laravel
FastAPI is an Open Source, modern, fast (high-performance), web framework for building APIs with Python 3.6+ based on standard Python type hints.

Mendix
Zoho Creator
Xamarin
Android Studio
Xcode
Firebase
Kissflow
Build Enterprise-Grade Apps Fast.

Which is more popular?
Based on our record, FastAPI seems to be a lot more popular than OutSystems. While we know about 312 links to FastAPI, we've tracked only 2 mentions of OutSystems.
Website, pricing, platforms and company facts side by side.
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| Website | fastapi.tiangolo.com | outsystems.com |
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| Company | Startup from Colombia | Startup from the United States · 1,000 - 1,999 employees · 2001 |
| Listed in |
What each product offers, as listed by its team.


Possible disadvantages
Possible disadvantages
An editorial look at what each product does well and who it suits.


Overall verdict
Why this product is good
Recommended for
Overall verdict
Why this product is good
Recommended for
Walkthroughs and reviews on video.
FastAPI from the ground up
More videos
Outsystems: Low-Code Apps - This Week in Enterprise Tech 317
More videos
How often each product is chosen within a category, 0–100% relative to the other.


Share your experience with using FastAPI and OutSystems. For example, how are they different and which one is better?
External articles and on-site reviews we used to compare the two products.


When our backend team needs to build services for data parsing, aggregators, or high-load APIs, FastAPI is our absolute go-to choice. It completely lives up to its name-development speed is outstanding. The...
FastAPI, as the name hints, is a swift mover. Built on Starlette, it’s all about speed and performance with Python. Crafting API masterpieces at the speed of light, now that’s something.
Since its release in 2018, it has rapidly gained popularity due to its great performance and simplicity. In fact, according to PyPi Stats, FastAPI has over 9 million monthly downloads, surpassing even full-stack...
OutSystems: Strong enterprise governance, lifecycle tooling, and AI-assisted development, with newer agent capabilities through Agent Workbench. Good fit for governed app delivery, but less suited to cross-system...
Strengths: This established low-code platform delivers rapid application development with a focus on scalability and security. OutSystems offers a mature platform ideal for building mission-critical enterprise...
Development With No Limits. Everything you need to build enterprise apps incredibly fast. Every aspect of OutSystems is crafted to help you build better apps faster and make changes easily. From high-productivity...
Recommendations tracked on public social media and blogs since March 2021.


I used FastAPI, a Python framework built specifically for creating APIs quickly, with automatic validation and interactive documentation baked in. - Source: dev.to / about 1 month ago
The Sovereign SDK is a Python-native framework designed to minimize prose overhead while generating ironclad, cryptographic execution receipts for AI agents, complete with drop-in FastAPI/Starlette ASGI middleware. - Source: dev.to / 4 months ago
We had a feature in production where a single user request could run for five-plus minutes — fetch documents, chunk them, hit an LLM per chunk, synthesize a final answer. We did the obvious thing first: a FastAPI handler that ran the... - Source: dev.to / 5 months ago
This month, I followed in the footsteps of many other OutSystems developers and completed the exam to become a certified Associate Reactive Developer. This exam focuses on the fundamentals of OutSystems reactive web and mobile... - Source: dev.to / over 2 years ago
Check out the AWS Architecture Blog to see how OutSystems designed a globally distributed serverless request routing service for its multi-tenant architecture. Source: over 5 years ago
When comparing FastAPI and OutSystems, you can also consider the following products.

a microframework for Python based on Werkzeug, Jinja 2 and good intentions.
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Mendix is the fastest and easiest low-code platform used by businesses to create and continuously improve mobile and web apps at scale.
Compare Mendix to FastAPI or OutSystems:

Sinatra inspired web development framework for node.js -- insanely fast, flexible, and simple
Compare ExpressJS to FastAPI or OutSystems:

Zoho Creator is a low-code application development platform that helps you build a custom, mobile-ready apps to run your business.
Compare Zoho Creator to FastAPI or OutSystems:

