API for Mobile App
Your app needs a backend. We build the API with authentication, data management, and push notifications.
By Danijel Balog, Founder, Fragon Studios · Last updated: April 18, 2026
Robust backend systems and APIs with C# and .NET. Hosted at Hetzner in Germany.
We build AND operate the system. No finger-pointing, fast reaction times, real responsibility.
Your application runs on enterprise-grade infrastructure. AMD EPYC processors, NVMe storage, redundant connectivity.
Fragon Cloud runs on Hetzner servers. No AWS, Azure, or GCP. Full control over your data.
Transparent, agile, and goal-oriented to success.
We analyze requirements, define interfaces, and create an architecture concept.
We document all endpoints before development. So frontend teams have something to work with early.
Development with automated tests. Every pull request is tested before it's merged.
Automatic deployment to our Kubernetes clusters. Monitoring and alerting included.
Your app needs a backend. We build the API with authentication, data management, and push notifications.
You want to connect SAP, Dynamics, or other systems. We build the middleware that makes data flow.
Process large data volumes or deploy ML models? We have the infrastructure and the know-how.
Four recurring backend engagements. Not exhaustive, just a sense of the range.
Problem: A SaaS vendor is growing past a single customer and needs clean tenant separation and a role-based API.
Solution: Six to ten weeks of .NET 10 API with schema-per-tenant on PostgreSQL, an RBAC layer, rate limiting, and OpenAPI docs, deployed on Fragon Cloud.
Problem: A mid-market company wants to connect new apps without rebuilding the legacy ERP and needs a stable API facade.
Solution: Four to six weeks of adapter layer in C#, caching for expensive calls, asynchronous replication into a modern PostgreSQL view, monitoring with OpenTelemetry.
Problem: A logistics platform needs to show status changes to dispatchers in realtime; today the frontend polls every five seconds.
Solution: Four to six weeks of backend with a SignalR hub for WebSocket streaming, an event-driven status model, and horizontal scaling via a Redis backplane.
Problem: A sales team pulls reports from three different tools every Monday and burns half a day on it.
Solution: Three to five weeks of ETL pipeline in .NET with a nightly batch job, a deduplicated target table, and a slim reporting API for an existing BI tool.
Custom-built software for processes standard SaaS doesn't cover. From internal tools to customer portals to ERP extensions. You get code, Git repository, and usage rights.
Right when: Clear requirement and no off-the-shelf software fits
Websites and web applications with the modern React stack. Fast load times, SEO-ready, CMS on request. Hosted on Fragon Cloud in Germany.
Right when: Website or web app that needs to be fast and well-indexed
iOS, Android, and web from one codebase with React Native and Expo. MVP in 8 to 12 weeks, including store submission and backend.
Right when: Idea you want to test as a real app in the market