Back to the board GUIDE
OutSystems or MERN: choosing the stack
We build on both. This is how we think about the choice.
OutSystems is a low-code platform. MERN (MongoDB, Express, React, Node.js) is a high-code stack. Each is strong in different conditions, so we choose per project.
Detailed stack comparison table
| Topic | OutSystems | MERN |
|---|---|---|
| Time to a working app | Visual development with built-in components and deployment tooling gives a short path to a first release. | More set-up at the start, since the team assembles the architecture, access control and pipelines. |
| Customisation | Broad, and extensible with custom code and integrations inside the platform's model. | Full control of every layer of the application. |
| Governance and security tooling | Environments, access control and deployment management come with the platform. | Built and maintained by the project team. |
| Ownership | Runs on the OutSystems platform under its licence. | Open-source stack; code and hosting are entirely yours. |
| Team skills | OutSystems specialists, with a faster ramp-up for visual developers. | Widely available JavaScript engineering skills. |
| Typical use | Workflow-heavy enterprise applications, portals and internal tools. | Products with a distinctive experience, real-time features or heavy AI components. Our Sonakshi voice agent is built on MERN. |
Choose OutSystems when
- You need a working application quickly.
- Your process is workflow-heavy and needs strong governance.
- Your team wants to maintain the application visually.
Choose MERN when
- The experience or logic is highly distinctive.
- You want full ownership of the code and hosting.
- The product leans on real-time or custom AI components.
PICK YOUR PRIORITIES
Compare your priorities
Select the factors that matter to your initiative. The recommendation adapts live.
SUGGESTED PEG Choose what matters to you.
Select one or more priorities above to compare approaches against your project goals.
A starting point. We finalise the approach together.
How we decide
Many projects use both: OutSystems for the workflow core and MERN microservices for the parts that need to be unusual. We recommend the combination that keeps your timeline and your long-term ownership goals in view.