14/03/2025 by Jodie Alexander
Migrating from one low-code platform to another is not only a technical exercise; it impacts architecture, governance, team dynamics, and collaboration methods. At apvine, we recently guided a client through migrating from OutSystems to Mendix and gained valuable lessons along the way.
Before the migration began, we assessed the existing OutSystems applications to determine their relevance. Some were outdated or could be consolidated, reducing the overall workload. Starting with simpler applications allowed us to refine our process efficiently before tackling more complex migrations.
We prioritized migrations according to business impact, carefully scheduling around resource availability, especially during busy or holiday periods.
One of our first strategic decisions was to start small—with a simple app to test the foundation. This helped us validate the infrastructure, reusable components, and enablement approach early on.
We assembled a focused core team responsible for setting up the infrastructure, enabling developers, and delivering our first Mendix application. This setup allowed us to demonstrate quick wins, build confidence and gather practical insights, giving us a solid base to scale the team and migration efforts in an informed way.
Making solid estimations upfront for each application is key. It gives you a clearer picture of the overall effort and helps with realistic planning.
And just as important: track time per application throughout the migration. This allows you to compare planned vs. actual effort, spot deviations early and adjust your approach where needed. It’s a simple practice that pays off quickly, especially when dealing with multiple apps and tight deadlines.
A successful migration demanded architectural planning. A comprehensive plan addressed dependencies and shared components upfront, clearly deciding their structure within Mendix, whether as separate apps, APIs, modules, or reusable building blocks.
Data migration strategies were also critical. Retaining OutSystems IDs in Mendix simplified the migration, although we avoided strictly replicating everything, leveraging Mendix’ features for greater efficiency.
OutSystems developers faced a notable learning curve when transitioning to Mendix. Initially, they resemble junior Mendix developers as they balance documentation, testing, data migration, learning Mendix fundamentals, and development tasks. However, they already have a significant advantage: familiarity with low-code development principles. While this accelerates their onboarding, it remains essential to grasp the key differences between the two platforms.
Our experts and developers with experience in both technologies played a crucial role in supporting this transition. The learning curve was a two-way street; while we guided them through Mendix, OS developers shared valuable knowledge about the existing applications and their structures.
Additionally, OS developers needed to adjust their perspective. Mendix treats each application as a distinct entity, unlike the centralized structure of OutSystems. This "application-as-a-house" architecture required careful planning around user management, authentication, and authorization.
Creating a reusable starter app significantly boosted our efficiency. This foundational app included standardized UI components and configurations, preventing duplication and ensuring consistency. A centralized internal marketplace facilitated component management, ensuring new developments were shared immediately across all teams. For example, a master data module was needed in all applications, making it a perfect candidate for reuse.
Clear governance established early prevented significant rework. We defined naming conventions, comprehensive documentation, structured branching strategies, and detailed deployment manuals, which greatly boosted productivity and facilitated onboarding new developers smoothly.
Testing was vital, and managing business expectations was key. From the start, we clarified that User Acceptance Testing (UAT) was strictly to validate migration accuracy, not to introduce new features.
We structured our testing in three phases:
Early data migration further supported realistic testing, quickly identifying and resolving potential issues.
Effective communication significantly impacts migration speed and quality. Excessive meetings can hinder progress, whereas insufficient communication can lead to misunderstandings and delays. We struck a balance with concise daily check-ins for immediate issues and broader weekly cross-team meetings to share insights and lessons learned. Additionally, we established a direct communication line between the Mendix developers and the Product Owner to resolve questions quickly.
A shared collaboration space in Microsoft Teams and the Mendix Portal streamlined documentation, demo recordings, and onboarding. Mendix developers also had access to OutSystems, allowing them to explore applications firsthand, both frontend and backend. Ensuring the right access from the start was crucial for efficiency. We maintained a clear checklist of all necessary permissions during onboarding.
No migration is risk-free, so having a fallback strategy is essential. For smaller, simpler applications, we prepared for potential detachment to .NET as a backup option. This ensured that if an app couldn’t be efficiently migrated to Mendix in time, there was an alternative pathway.
Migrating from OutSystems to Mendix is more than technical, it requires thoughtful planning, strong communication, and flexibility. At apvine, our practical experience ensures your transition is smooth, manageable, and transformative.
Considering a Mendix migration? apvine is here to support you every step of the way.