References

Projects from over 15 years of team experience

Over 15 years, the appDev team has worked on more than two hundred projects, from clearly scoped initiatives at mid-sized companies to large-scale programs at major enterprises. A large share of that work is mid-market and quick to reach production. That is exactly where our focus lies. Below is a selection across industries and sizes.

Case studies

Selected projects.

26 projects

AI and RAG small to mid-sized

Document recognition with handover to the ERP

Document processing with a human in the loop

Task

Receipts and orders arrive as PDFs, scans and emails and are currently entered by hand.

Solution

Extraction of the relevant fields, a proposal for approval, handover to the ERP. The final sign-off stays with the team.

  • OCR
  • Azure OpenAI
  • .NET
  • REST to the ERP
  • PostgreSQL

Fixed-price pilot, then expansion · Fixed-price pilot

Manual prep work drops noticeably, while approval stays with the clerk.

Document processing
Health and telematics large

Electronic health record for a large statutory health insurer

Native Android app in the telematics infrastructure

Task

Insured members need to manage documents, permissions and modules of the electronic health record securely on their smartphone, in a strictly controlled environment with strict audit requirements.

Solution

A new interface on an existing white-label base, FHIR data models, sign-in via the sectoral identity provider, consent management, integration of further specialist services such as the e-prescription and emergency data. Complete auditability and documentation designed for the Gematik audit.

  • Kotlin
  • Jetpack Compose
  • Dependency Injection
  • FHIR
  • Telematics infrastructure
  • sekIDP
  • Jenkins
  • CI/CD

Team of around ten people, multi-year · Contract-based work within the product team, full code with the client

Passed the Gematik audit and in regular operation.

Health data (ePA, FHIR)
Retail and logistics mid-sized

Internal sales assistant for product data and terms

RAG assistant over product and pricing data

Task

The internal sales team looks up product details, prices and availability across many catalogs and systems, which costs time on every inquiry.

Solution

An assistant answers questions from the approved data sources with source references and respects roles and permissions. Connected to the inventory management system.

  • Node.js
  • Vector database
  • Azure OpenAI
  • role-based permissions
  • REST to the inventory system

Fixed-price pilot, then operation · Fixed-price pilot, full code with the client

Answers come with a source, and searching across multiple systems is no longer needed.

Knowledge search with RAG
AI and RAG small to mid-sized

AI assistant for quotes and cost calculations

A suggestion system for internal sales

Task

Calculating a first quote from incoming inquiries takes the internal sales team a lot of time.

Solution

The inquiry is analyzed and a calculation proposal is generated. Sales reviews and approves it; responsibility stays with people.

  • Azure OpenAI
  • .NET
  • Calculation and master data
  • PostgreSQL

Fixed-price pilot · Fixed-price pilot

The first draft quote comes together faster, while approval stays with sales.

Document processing
Industry mid-sized

Cross-platform app with a shared core

iOS and Android with shared logic via Kotlin Multiplatform

Task

An application needs to behave identically on both platforms without maintaining the business logic twice.

Solution

The database and API client written once in Kotlin Multiplatform, embedded in a SwiftUI and a Compose interface. Shared tests, separate native interfaces.

  • Kotlin Multiplatform
  • Swift
  • SwiftUI
  • Kotlin
  • Jetpack Compose
  • GraphQL
  • Apollo
  • SQLDelight
  • Fastlane

Team of around eight people · Contract work within the product team

One shared codebase for the logic, two native apps in operation.

Have an app built
Finance and insurance large

Software modules for a major German bank

Backend and application modules with compliance requirements

Task

The banking environment sets high requirements for auditability, traceability and stability.

Solution

Development of individual modules following the compliance requirements common in banking, with clean documentation and test coverage.

  • Java
  • Spring
  • REST
  • PostgreSQL
  • automated tests

large program, long-running · Contract-based work within the program

Modules in production within an audit-regulated environment.

Technical consulting
AI and RAG mid-sized

RAG knowledge assistant with source references and access control

Internal knowledge search based on large language models

Task

Employees find knowledge in the wiki, documents and tickets only slowly, and the answer needs to be auditable and permission-safe.

Solution

Retrieval with source references, access control at the document level, every answer with evidence. Built on the existing backend and security DNA.

  • .NET
  • Node.js
  • Vector database
  • Embeddings
  • Azure OpenAI
  • role-based permissions
  • PostgreSQL

Fixed-price pilot, six to eight weeks, then operation · Fixed-price pilot, full code with the client

Answers come with a source and respect read permissions.

Knowledge search with RAG
Industry mid-sized

Field-service app with offline operation

Native Android app for field use

Task

Technicians in the field often work with a weak connection and need job data, photos and data capture even with no reception.

Solution

Local data storage with later synchronization, photo and capture features, distribution via enterprise channels.

  • Kotlin
  • Jetpack Compose
  • Coroutines
  • Room
  • Retrofit
  • Managed Google Play

small team, several months · Contract work

In use by the field-service team, with data capture working offline too.

Native Android apps
Energy and utilities large

Customer portal and self-service for an energy utility

Web portal with backend integration

Task

A utility's customers need to submit meter readings, manage contracts and view invoices, anytime and on their own.

Solution

A self-service portal with a clear interface, connected to the billing and contract systems. Designed for many concurrent users.

  • React
  • TypeScript
  • .NET
  • Java
  • PostgreSQL
  • REST
  • EU hosting

large team, long-running · Contract work within the program

Customers handle standard tasks themselves, easing the load on customer service.

AI in your systems
Retail and logistics mid-sized

Capturing and automatically matching delivery documents

Document processing with a human in the loop

Task

Delivery notes, freight papers and invoices arrive in many formats and are sorted and entered by hand.

Solution

Extraction of the relevant fields, matching to the right transaction, handover to the target system. Edge cases go to a staff member for review.

  • OCR
  • Azure OpenAI
  • .NET
  • Workflow engine
  • REST integration

Fixed-price pilot, then operation · Fixed-price pilot

Documents land on the right transaction automatically, while review of edge cases stays with the team.

Document processing
Health mid-sized

iOS health app with a personalized score

Native iOS app with a subscription model

Task

After a health questionnaire, users should receive relevant content daily, with clean subscription logic and data-minimal analysis.

Solution

Questionnaire, score calculation and daily rotating content. Subscription via in-app purchase, content behind a valid subscription. Automated deployment for multiple environments.

  • Swift
  • SwiftUI
  • The Composable Architecture
  • Firebase
  • In-app purchase
  • Fastlane
  • GitHub Actions

small team, several months · Lead iOS, contract work

Published on the App Store, since operated by the client's team.

Native iOS apps
Web, backend and cloud mid-sized

AI integration into an established ERP and legacy landscape

AI features connected to existing systems

Task

A company wants to use AI while keeping its established ERP and legacy landscape.

Solution

Integration with SAP and database interfaces, controlled data handover, AI features layered on top of the existing systems. The existing investment is preserved.

  • .NET
  • Node.js
  • SAP interfaces
  • REST
  • Vector database
  • Docker

several months · Contract work

The AI features run on the existing system, which stays fully intact.

AI in your systems
Retail and logistics mid-sized to large

Shopping app for iOS and Android

Native apps for both platforms with payment

Task

A retailer wants a seamless shopping experience on the smartphone, with sign-in, payment and recommendations.

Solution

Native apps for iOS and Android, connected to the shop backend, payment via established SDKs, personalized content and push.

  • Swift
  • SwiftUI
  • Kotlin
  • Jetpack Compose
  • GraphQL
  • Payment SDK
  • Push Notifications

Team of around eight people · Contract work within the product team

Two native apps in the store, in continuous operation with payment and personalization.

Have an app built
Health and telematics mid-sized

Document-to-FHIR extraction for lab and billing data

Structuring unstructured health data into FHIR

Task

Findings and billing documents exist in unstructured form and should be processed further as clean FHIR resources.

Solution

Extraction, mapping to FHIR profiles, validation and handover to the target system. A review step with professional sign-off.

  • OCR
  • LLM
  • FHIR
  • Validation
  • .NET
  • EU hosting

Fixed-price pilot · Fixed-price pilot

Documents become validated FHIR resources for further processing.

Health data (ePA, FHIR)
Industry mid-sized

Technical service knowledge assistant for machinery and plant engineering

RAG over technical documentation for service teams

Task

Service technicians on site need to find the right passage quickly in extensive manuals and service documents.

Solution

An assistant searches the technical documentation and returns the relevant passage with its source. Built on the existing backend and security DNA.

  • Node.js
  • Vector database
  • Embeddings
  • Azure OpenAI
  • Document pipeline

Fixed-price pilot · Fixed-price pilot

The right information is available faster on site, with a source for every answer.

Knowledge search with RAG
Health and telematics mid-sized

GesundheitsID login and telematics integration as a building block

Connecting a health application to the telematics infrastructure

Task

A health application needs to sign users in via the GesundheitsID and connect to services of the telematics infrastructure.

Solution

Sign-in via the sectoral identity provider, integration with the approved components, built and handed over as a self-contained building block.

  • GesundheitsID
  • sekIDP
  • FHIR
  • Telematics infrastructure
  • REST
  • EU hosting

Fixed-price building block · Fixed-price building block as an integration partner on the approved infrastructure

Sign-in and integration run inside the client's product.

Health data (ePA, FHIR)
Finance and insurance mid-sized

Customer app for policies and claims reporting

Native app with document upload

Task

Policyholders should be able to view policies, report claims and upload documents directly in the app.

Solution

A native app with a policy overview, claims reporting with photo upload and secure sign-in. Connected to the core insurance systems.

  • Swift
  • SwiftUI
  • Kotlin
  • Jetpack Compose
  • REST
  • secure authentication

several months · Contract-based team reinforcement

Policies and claims reporting run through the app, connected to the core systems.

Have an app built
Health small

On-device AI in an iOS app

AI feature directly on the device

Task

An app should analyze inputs intelligently, and the analysis should stay local on the device.

Solution

A model runs on-device and the analysis happens locally. Data-minimal and with a short path.

  • Swift
  • Core ML
  • SwiftUI
  • HealthKit

A feature within a live product · Contract work, feature development

The analysis runs on the device and the data stays local.

AI in your systems
Web, backend and cloud mid-sized

Platform frontend with a design system and accessibility

Web frontend for a SaaS platform

Task

A growing platform needs a consistent, accessible frontend that can be extended quickly.

Solution

A reusable component and design system, accessible to the common standards, documented for the internal team.

  • React
  • TypeScript
  • Design system
  • Storybook
  • WCAG-compliant components

several months · Contract work, later handed over to the internal team

A consistent, accessible frontend that the internal team can extend on its own.

Technical consulting
Web, backend and cloud small

Quality and release setup as a module takeover

An engineering task across platforms

Task

A team loses time to manual releases and inconsistent quality assurance.

Solution

An automated pipeline, consistent tests including snapshot tests, monitoring of test coverage and code quality.

  • Fastlane
  • GitHub Actions
  • Jenkins
  • SonarQube
  • XCTest
  • Espresso

a scoped package, a few weeks · Module takeover at a fixed price

Releases run automatically and code quality is monitored measurably.

Technical consulting
Health and telematics mid-sized

Tablet app for documentation at the point of care

Android tablet app for everyday care work

Task

Care staff document right at the bedside and need fast, robust data capture that works even with a weak connection.

Solution

A tablet app with clear data capture, local storage and later synchronization, designed for everyday care work.

  • Kotlin
  • Jetpack Compose
  • Room
  • Coroutines
  • Managed Devices

small team, several months · Contract work

Documentation happens right at the point of care, even with a weak connection.

Native Android apps
Web, backend and cloud mid-sized to large

Cloud migration and platform modernization

Modernization of an established application

Task

An established application runs on old infrastructure and is hard to maintain; it should become more stable and quicker to roll out.

Solution

A step-by-step move into containers, automated pipelines, monitoring and a clear operating path. Ongoing operation is preserved throughout the transition.

  • Docker
  • Kubernetes
  • Terraform
  • GitHub Actions
  • Monitoring
  • Azure or AWS in the EU

several months · Contract work, modernization and handover

The application runs on modern infrastructure, and releases are automated and traceable.

AI in your systems
App and mobile mid-sized

Senior reinforcement in a live product team

Experienced developers into an existing team

Task

A product team lacks experienced iOS or Android capacity for a phase.

Solution

Senior developers reinforce the team, work within its processes and hand over cleanly documented code.

  • Swift
  • Kotlin
  • depending on the target product

Team reinforcement over several months · Team reinforcement, contract for work or services depending on the agreement

The team delivers the phase, and the code stays maintainable in its hands.

Find app developers
Finance and insurance mid-sized to large

Payment and billing backend with interfaces

Backend with high requirements for correctness and traceability

Task

Payments and billing must be processed correctly, logged cleanly and connected to several systems.

Solution

A backend with clear interfaces, event-based processing and complete logging, designed for high load.

  • Java
  • Spring
  • .NET
  • event-based processing
  • PostgreSQL
  • REST

long-running · Contract-based work

Payments and billing run traceably and connected to the surrounding systems.

Technical consulting
Mobility large

App for a transport and mobility provider

Native app with high availability and data requirements

Task

An app with many users needs to work reliably even with a fluctuating connection and display real-time data cleanly.

Solution

Robust offline capability, clear synchronization and an architecture that handles high load and frequent releases.

  • Swift
  • SwiftUI
  • Swift Concurrency
  • Combine
  • REST
  • Fastlane
  • XCTest

large team, long-running · Contract-based team reinforcement

In continuous operation with high user volume.

Native iOS apps
Public sector large

Secure specialist applications for the public sector

Specialist applications with high requirements for data protection and auditability

Task

Public-authority specialist applications need data protection, traceability and long, stable operating periods.

Solution

Development and maintenance of specialist applications with clear permission and logging logic, designed for years of operation.

  • Java
  • REST
  • PostgreSQL
  • Logging
  • EU hosting

long-running · Contract work

In regular operation over long periods.

Technical consulting

Tell us about your project.

In a short conversation we map out what makes sense for you and what a first step could look like.