Retrofit Experts in Germany
matched in minutes with vetted, available freelancersHire experts who connect Android apps to REST APIs, define type-safe service interfaces and handle authentication, serialization and error flows with Retrofit, OkHttp and converters. FRATCH matches you quickly and precisely with vetted, available freelancers.
Meet FRATCH Experts in Germany, who have recently used Retrofit
Timo T.
Last position:
Gronic Ident & Sign at Gronic Systems GmbH
Gronic Ident & Sign
Core technologies: Android, Jetpack Compose, Retrofit, Regula Document Reader, Adobe Sign
Android app on dedicated devices for identifications and electronic signatures at the PoS
James C.
Last position:
Freelance Android Developer at Normalis
- Working on Telecommunication Apps on Android under NDA for the Military
- Participation in the development of backend services (Spring, Java)
- Android Development, Kotlin, Compose, REST, JSON, State-Machines, Android Studio, IP Communication, Cybersecurity, Agile
Mathias V.
Last position:
Fullstack AI Engineer at Ammodia.com
Developed a custom Kotlin Multiplatform app with a Spring backend and AI features.
Steven M.
Last position:
Freelance Trainer at TÜV Rheinland Akademie
- Practical seminar “Generative AI in Software Development”
- Mobile apps and cloud computing
- Internet of Things, smart home, and consumer healthcare
- The future of mobile communication
Ayhan G.
Last position:
Senior QA Engineer / Test Automation Engineer / SDET at Rewe digital
Consulting, designing, and implementing the software testing lifecycle for multiple Android apps and backends Introducing test automation with Appium, SpringBootTest, RestAssured Setting up and managing emulators Developing an E2E library, an integration library, a Testcontainers library, and other libraries Developing, implementing, and advising on CI strategies Building the test environment with Testcontainers and virtualization Developing and implementing test cases for integration tests and end-to-end tests Establishing a maintainable test architecture with low entry barriers to simplify the creation of automated tests Some tools and technologies used: JUnit, RestAssured, Testcontainers, Kubedock, Appium, Android emulator, Jira Xray, Mockito, WireMock, Spring Framework, Kotlin
Matthias E.
Last position:
Lead Android Developer at Star Finanz-Software Entwicklung und Vertriebs GmbH
- Further development of the Android app "StarMoney"
- Major XML to Compose redesigns
- Introduction of new technologies and architecture
- Implementation of instant bank transfer
- Development following the agile Scrum process
Umer D.
Last position:
Activation and Vocational Integration Program with Integrated Language Support at Berlitz
- Intensive language course with a focus on professional language content.
Rafael K.
Last position:
Senior Android Developer / Team-Lead at IBM Deutschland
- Further development and release support for a white-label ePA component for health insurance companies
- Technologies: Android (Kotlin), Kotlin Multiplatform, Coroutines, Jetpack Compose, MVVM, StateFlow, Gradle, ProGuard
Burak C.
Last position:
Senior Android Developer at Awesome Technologies GmbH
- Optimized the Amp healthcare app alongside a senior developer, specifically enhancing data caching mechanisms which led to a 25% improvement in load times.
- Applied MVI architecture, resulting in a 30% decrease in bugs and streamlining testing processes.
- Implemented CI/CD with Bitrise, reducing deployment sizes from 120MB to 104MB.
- Led the migration of 40% of the Java codebase to Kotlin.
- Achieved 85% unit test coverage.
M Samy H.
Last position:
Android Developer at Check24 GmbH
- Developed and maintained the large-scale Check24 car insurance native Android app serving millions of users using Jetpack Compose.
- Owned the end-to-end implementation of new features, including planning, development, and delivery in an Agile/Scrum environment.
- Refactored legacy Java code into a modern Compose architecture, improving maintainability and long-term scalability.
- Performed code reviews for team members via Bitbucket, ensuring code quality, architectural consistency, and Kotlin best practices.
Dmitrii S.
Last position:
Senior Developer/Team Lead at Devexperts
Project Livebash (2021-12-01–2023-12-31)
Development and design of the core system
Code reviews
Developer management
CI/CD
Client communication
Leading epics
Speaking at conferences
Managing the production system
Interviewing project developers
Outcome: production system
Technologies and tools: Java 11, Java 17, Kotlin, Spring Boot, TeamCity, Gradle, AWS DynamoDB, JUnit, Mockito, Docker, Docker Compose, AWS SQS, AWS EC2, AWS S3, AWS MediaLive, Ethereum, Postman
Project Robinhood (2024-01-01–2024-05-31)
Customization and development of product features for specific clients
Interviews with project developers
Technologies and tools: Java 17, Java RX, Kotlin, Spring Boot, TeamCity, Gradle, JUnit, Mockito, Docker, Docker Compose, PostgreSQL
Projects Sway, Tickmill, Pepperstone, UCapital (2024-06-01–present)
Customization and development of product features for specific clients
Bug fixes
Porting tickets from the product
Feature development
Technologies and tools: Java 17, Java RX, Kotlin, Spring Boot, TeamCity, Gradle, JUnit, Mockito, Docker, Docker Compose, PostgreSQL
Yodgorbek K.
Last position:
Android Developer at Mein Artz
- Led the development of a doctor scheduling Android app, integrating Jetpack Compose and Kotlin Multiplatform, achieving a 30% performance improvement.
- Implemented complex UI components, ensuring 99.8% crash-free user sessions.
- Seamlessly integrated Compose UI with existing View-based components.
- Optimized API calls, reducing load times by 20%.
- Tech Stack: Kotlin, Jetpack Compose, KMM, MVVM, Koin, Firebase, Stripe API, Crashlytics
Jan G.
Last position:
Master Data Application at confidential
Visualization, search, and maintenance of various types of master data, providing them via a REST API, and implementing a variety of import and export formats.
Implementation, architecture, project management.
Technologies and tools: Angular (Signals, Signal Store, swagger-codegen, standalone components), Java, PostgreSQL, ActiveMQ, JavaScript, Spring Boot (Spring Core, Spring MVC, Spring Data/JPA via Hibernate, Spring Security, Spring Modulith), JUnit, Flyway, QueryDSL, GraphQL, REST API, Node, npm, Maven, SonarQube, GitLab CI/CD pipelines, Docker, Nexus, OpenAPI + Swagger UI, Keycloak, OAuth2, OpenID Connect, IntelliJ IDEA, Jira, Confluence.
Md. Shah S.
Last position:
Android Engineer at ScrapBays Ltd.
- Built features using Jetpack Compose
- Improved location-based features with in-memory caching
- Developed Merchant-to-Merchant chat functionality from scratch
- Integrated FCM with deep links to enable contextual push notifications
- Performance tuning for Google Maps view using clustering for better performance in dense areas
Anurag K.
Last position:
Software Development Engineer - Mobile at Krian GmbH
- Engineered the App-Connect module for Volkswagen HMI systems (Passat, Golf, ID series), reducing smartphone pairing time by 30%.
- Developed SABGWALA, a Flutter-based e-commerce app with Clean Architecture, increasing daily active users by 40%.
- Delivered Det-Medex, an Android ML app using MediaPipe, improving real-time body tracking by 25%.
- Integrated a TensorFlow module into the Android and iOS modules of the Det-Medex app, using Jetpack Compose for design and Kotlin for the camera module.
- Utilized Firebase Core, Firebase Auth, and Firebase Cloud Storage for backend services.
- Implemented Clean Architecture with Get_It for dependency injection.
- Managed routing with Go_router and state management with flutter_bloc.
- Supported both German and English languages in the application.
- Developed and maintained the App-Connect application for Volkswagen, improving connectivity reliability with Apple CarPlay, Android Auto, and MirrorLink by 20%.
- Enhanced user interface and experience, resulting in a 15% increase in user satisfaction.
- Implemented robust Bluetooth and USB connectivity features, reducing connection errors by 25%.
- Collaborated with cross-functional teams in an agile environment, leading to on-time delivery of key milestones.
Discover over 15,000 top freelancers
Statistics of experts using Retrofit
Aggregated from the professional profiles of matched freelancers.
Experience
13 years
Position duration
1.6 years
Positions per freelancer
13
Top business areas
Information Technology, Product Development, Project Management
Top industries
Information Technology, Transportation, Healthcare
Certification focus areas
Information Technology, Product Development, Project Management
Bachelor's degree or higher
86%
Master's degree or higher
50%
Certifications per freelancer
1
Most common languages
German, English, Turkish
Speak two or more languages
100%
Based on our profile pool as of 29 Oct 2026.
Daily rate distribution
The chart shows how the daily rates of experts in this technology in Germany are distributed, based on recent contracts on our platform. Each bar covers a rate range — its height shows the share of experts charging within that range.
Average rates of experts in Germany using Retrofit
Rates are based on recent contracts and do not include FRATCH margin.
The average daily rate is the mean of all daily rates from recent contracts of comparable freelancers on our platform.
The median daily rate is the middle value of all daily rates — half of comparable freelancers charge less, half charge more. Unlike the average, it is barely affected by outliers.
Calculated based on our freelancers’ daily rates as of 29 Oct 2026. Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.
Retrofit experts industry focus
See which industries our matched freelancers work in most often — every figure is calculated live from the freelancers on FRATCH.
- Information Technology (100%)
- Transportation (56%)
- Healthcare (50%)
- Insurance (44%)
- Retail (44%)
- Telecommunication (44%)
- Automotive (38%)
- Media and Entertainment (38%)
Please note that freelancers can work across multiple industries, so percentages overlap.
About the technology
Android API Layer
Retrofit is a type-safe HTTP client for Android and the JVM. It turns REST API definitions into clear Kotlin or Java interfaces, reducing repetitive request code while keeping network calls easy to test and maintain. It is commonly used in mobile apps that consume structured backend services.
Core Ecosystem
Retrofit is maintained by Square and usually works alongside OkHttp for connections, interceptors and caching. Experts also configure converters such as Gson, Moshi or kotlinx.serialization, plus Kotlin coroutines, RxJava or Call adapters for asynchronous work. Familiarity with Gradle, Android Studio and API documentation is essential.
Typical Deliverables
- Define service interfaces for REST endpoints
- Configure JSON serialization and custom converters
- Add authentication, headers, logging and retry handling
- Connect API responses to repositories, ViewModels and UI state
- Write unit and integration tests for network behavior
When Expertise Helps
Companies bring in freelance Retrofit specialists when an Android app needs a new backend integration, a reliable networking layer or a structured migration from handwritten HTTP code. They can also resolve inconsistent API models, fragile error handling and slow delivery caused by unclear client-server contracts. Teams in Germany often combine remote collaboration with occasional on-site workshops when product and backend groups need close alignment.
Strong Professional Skills
A strong professional understands HTTP methods, status codes, headers, JSON schemas and REST conventions, not just Retrofit annotations. They map remote data into safe domain models, handle offline and partial-failure states, and keep secrets out of the client. They also know when to use suspend functions, Flow or another asynchronous approach without coupling the app too tightly to its transport layer.
Quality Checks
Look for a specialist who can explain the boundary between Retrofit, OkHttp and application architecture. Review examples showing typed responses, cancellation, timeout settings, authentication refresh and meaningful tests rather than only successful requests. During collaboration, clear API assumptions, documented edge cases and consistent code reviews are strong signs that the networking layer will remain dependable as the app grows.
Frequently asked questions
What clients ask us most about Retrofit — answered in short.
Retrofit is used to call HTTP APIs from Android and JVM applications through typed service interfaces. It handles request definitions and response conversion, while OkHttp manages the underlying network connection. Teams commonly use it for REST integrations such as accounts, payments, catalogs and messaging.
Retrofit provides a declarative API layer on top of OkHttp, so specialists describe endpoints with interfaces and annotations. OkHttp offers lower-level control over requests and connections, while Ktor Client can serve broader Kotlin and multiplatform use cases. The right choice depends on platform scope, existing architecture and how much control the team needs.
A strong Retrofit specialist should also understand OkHttp, Kotlin coroutines, JSON converters and Android architecture patterns such as repositories and ViewModels. Useful adjacent skills include OAuth or token authentication, API contract testing, Gradle configuration and observability. Experience with backend API documentation helps prevent client-server misunderstandings.
The right level of Retrofit experience depends on the integration risk, not simply the size of the codebase. A straightforward endpoint connection may need focused support, while a complex app with authentication renewal, offline behavior and several API versions benefits from a specialist who has handled those cases before. Ask candidates to describe comparable networking decisions and trade-offs.
Retrofit work is usually well suited to remote collaboration because interfaces, API contracts and tests can be reviewed in shared repositories. Teams in Germany may still prefer occasional on-site workshops for architecture or release planning. Clear English documentation is common, while German-language communication can help when the wider product team expects it.
Review whether the Retrofit implementation separates transport models from domain models and handles failures explicitly. Check timeout configuration, cancellation, authentication refresh, logging safeguards and test coverage for non-success responses. A quality specialist should explain these choices clearly and show how the code stays maintainable when the API changes.
Retrofit supports Kotlin suspend functions and can work with Flow through appropriate application patterns or adapters. It also integrates with RxJava when a project already uses reactive streams. The important question is whether the chosen approach fits the app's lifecycle, cancellation behavior and existing state-management design.
Teams often choose Retrofit when repeated request code, inconsistent parsing or difficult testing slows Android delivery. Its typed interfaces and converter ecosystem can make API integrations clearer and easier to review. A migration still requires care around custom headers, retries, caching, error formats and behavior that existing users depend on.
The average hourly rate of freelancers in Germany who have used Retrofit in their recent projects is 75 €, which corresponds to a daily rate of about 598 € based on an 8-hour working day.
Of the freelancers in Germany who have used Retrofit in their recent projects, 86% hold at least a Bachelor's degree and 50% hold at least a Master's degree.
On average, freelancers in Germany who have used Retrofit in their recent projects have 13 years of professional experience, with a single engagement typically lasting around 1.6 years.
The most common languages among freelancers in Germany who have used Retrofit in their recent projects are German (100%), English (94%), and Turkish (13%).
The most common industries among freelancers in Germany who have used Retrofit in their recent projects are Information Technology (100%), Transportation (56%), and Healthcare (50%).
The most common business areas among freelancers in Germany who have used Retrofit in their recent projects are Information Technology (100%), Product Development (100%), and Project Management (38%).
Main locations of FRATCH Experts, who have recently used Retrofit
Our freelancers and interim experts are at home across the DACH region — available on-site in the major business hubs or fully remote. Choose a location to discover matched specialists, local market insights and up-to-date availability.
Berlin Hamburg Munich Cologne Frankfurt Stuttgart Dusseldorf Leipzig Dortmund Essen Bremen Dresden Hanover Nuremberg Request a free demo
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Philipp Thomaschewski
FRATCH CEO
