Retrofit Experts in Germany
, matched with vetted and available freelancers in minutesHire experts who design type-safe HTTP clients, connect Android apps to REST APIs and manage Kotlin or Java networking with tools such as OkHttp and Gson. Get fast, precise matching with vetted, available freelancers.
Meet FRATCH Experts in Germany, who have recently used Retrofit
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
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
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.
Md A.
Last position:
Software Engineer (Android - Kotlin, Jetpack Compose) at BJIT Ltd
- Led high-impact projects for multinational clients, including Sony, Rakuten, Netflix, and Zalando, delivering next-generation solutions
- Spearheaded the development of Android applications using Kotlin and Flutter, boosting user interface speed by 30% and implementing MVVM and Clean Architecture
- Orchestrated the integration of REST APIs to fetch and present data with 100% accuracy and uptime, ensuring a seamless user experience
- Enhanced local data storage solutions by utilizing RoomDB, SharedPreferences, and DataStore, reducing application load times by 15%
Mathias V.
Last position:
Senior Android Developer / Freelancer at Adevinta
- Further development of the classifieds app
- Android
- Kotlin
- Coroutines
- Jetpack Compose
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
11
Top business areas
Information Technology, Product Development, Quality Assurance
Top industries
Information Technology, Healthcare, Transportation
Certification focus areas
Information Technology, Product Development, Business Intelligence
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 19 Sep 2026.
Daily rate distribution
The chart shows how the daily rates of freelancers in this technology in Germany are distributed, based on recent contracts on our platform. Each bar covers a rate range — its height shows how many freelancers charge 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 19 Sep 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%)
- Healthcare (53%)
- Transportation (53%)
- Insurance (47%)
- Automotive (40%)
- Retail (40%)
- Telecommunication (40%)
- Education (33%)
Please note that freelancers can work across multiple industries, so percentages overlap.
About the technology
What Retrofit Does
Retrofit is a type-safe HTTP client for Android and Java applications. It turns REST API definitions into clear Kotlin or Java interfaces, reducing repetitive networking code. Applications use it to request data, submit forms, upload files and handle authentication against backend services.
Core Integration Work
Retrofit specialists define service interfaces, request models and response types that match an API contract. They configure converters for JSON or other formats, manage asynchronous calls and expose reliable data flows to the application layer. Their work often covers both new integrations and difficult API migrations.
Ecosystem And Tooling
Retrofit commonly works with OkHttp for connections, interceptors, caching and logging. Kotlin Coroutines, RxJava and Java executors support different asynchronous approaches, while converters such as Gson, Moshi and kotlinx.serialization map payloads into application models. Strong specialists also understand Gradle, Android Studio and API documentation tools.
- Define endpoints, headers, query parameters and request bodies
- Map JSON responses and error payloads to safe models
- Configure authentication, retries, timeouts and interceptors
- Test service interfaces with mocked or local API responses
When Companies Need Help
Companies bring in freelance Retrofit expertise when an Android product must connect to a new backend, replace fragile networking code or support a changing API. The need is common in mobile products, connected services, commerce applications and internal business apps. In Germany, remote collaboration is often practical when API documentation and delivery standards are clear; on-site work can help when mobile and backend teams must align closely.
- Stabilise failed requests, parsing issues or inconsistent error handling
- Move from manual HTTP calls or another client to Retrofit
- Prepare a networking layer for multiple environments and releases
- Review an integration before a major mobile launch
What Strong Professionals Bring
A strong professional goes beyond creating endpoint interfaces. They separate transport models from domain models where useful, handle lifecycle and cancellation concerns, protect sensitive data and make failures visible to users and monitoring systems. They also read API contracts critically and communicate clearly with backend, product and quality teams.
Choosing The Right Specialist
Assess examples of real Retrofit integrations rather than only familiarity with the library name. Ask how the specialist handled token refresh, pagination, malformed responses, offline behaviour and automated tests. Review the proposed package structure, error strategy and approach to backward compatibility. A good match understands the surrounding Android application as well as the HTTP client itself.
Frequently asked questions
What clients ask us most about Retrofit — answered in short.
Retrofit is used to call REST and other HTTP APIs from Android or Java applications through typed service interfaces. It handles request construction, response conversion and asynchronous execution, while the application controls how the returned data is displayed and stored.
Retrofit is a higher-level API client built to describe endpoints as interfaces, and it commonly uses OkHttp underneath for network transport. Ktor Client offers a broader multiplatform approach and more direct request control, while Retrofit is often preferred for established Android codebases with REST contracts.
A strong Retrofit specialist should understand Kotlin or Java, Android application architecture, HTTP, JSON, authentication and Gradle. Experience with OkHttp interceptors, Kotlin Coroutines, Moshi or Gson, testing and API documentation is also valuable.
The right level depends on the integration’s risk, not simply on the size of the codebase. A straightforward endpoint connection may need focused library knowledge, while a large migration or unreliable API calls for a specialist who has handled concurrency, token renewal, caching, testing and production failures with Retrofit.
Retrofit work is usually well suited to remote collaboration because interfaces, API contracts and test results can be reviewed digitally. Teams should agree on documentation, code review, working language and access to development environments; on-site sessions can still help when Android and backend specialists need close coordination.
Review whether the Retrofit integration has clear service interfaces, typed models, consistent error handling and tests for successful and failed responses. Ask the specialist to explain cancellation, lifecycle safety, authentication, logging and how the design would adapt when the API changes.
Retrofit supports Kotlin Coroutines directly and can also be combined with reactive approaches such as RxJava. The choice depends on the application’s architecture and existing conventions, so a specialist should explain how cancellation, threading and error propagation will work across the data layer.
A team may choose Retrofit when it wants a readable, typed description of API operations instead of repetitive request code. Manual calls can provide lower-level control, but they place more responsibility on the team for URL handling, parsing, failures and consistent testing.
The average hourly rate of freelancers in Germany who have used Retrofit in their recent projects is 77 €, which corresponds to a daily rate of about 618 € 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 (93%), and Turkish (13%).
The most common industries among freelancers in Germany who have used Retrofit in their recent projects are Information Technology (100%), Healthcare (53%), and Transportation (53%).
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 Quality Assurance (40%).
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 
Berlin Request a free demo
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Philipp Thomaschewski
FRATCH CEO
