Hire the best Kotlin Developers in Belgrade, RS
Check out Kotlin Developers in Belgrade, RS with the skills you need for your next job.
- $40 hourly
- 4.9/5
- (3 jobs)
As an experienced Flutter developer with over 5 years of experience, I specialize in building high-quality mobile apps for both iOS and Android platforms. With a strong background in both Flutter framework and Dart programming language, I am passionate about creating elegant, intuitive, and scalable apps that meet the needs of modern businesses. Throughout my career, I have worked with a variety of clients and industries, from small startups to large corporations. My expertise includes developing custom mobile apps, integrating third-party APIs, and building complex UI/UX designs. I am also proficient in using Firebase for backend development and integrating payment gateways into mobile apps. What sets me apart as a Flutter developer is my attention to detail, focus on quality, and ability to deliver projects on time and within budget. I am committed to working closely with my clients to understand their needs and goals, and to provide them with innovative solutions that meet their specific requirements. If you're looking for a skilled Flutter developer who can deliver top-notch mobile applications, then look no further! Let's discuss your project requirements and get started. What I can do for you: ✅ Expert Mobile Architect Flutter (TDD, DDD) ✅ Flutter State Management (Getx, Provider, Bloc, RxDart, Riverpod) ✅ Offline Mode using local DataSource ( Hive | SQFLite | SharedPref ) ✅ Publish +10 Apps in my career on Google Play & AppStore ✅ CI/CD pipeline TestFlight / App Test(Firebase) & AppStore/PlayStore ✅ - Firebase integration - Authentication, Cloud Messaging (push notifications), Crashlytics, Analytics, Firestore Database. ✅ Worked using Agile (Scrum Methodology) with the latest tools (Trello - JIRA - ClickUp - CodeMagic - Git - Slack ..etc) ✅ Online sync / Caching ✅ GraphQL / REST API ✅ Android development (Kotlin/Java) - Jetpack Compose ✅ Worked as a team leader using Agile (Scrum Methodology) with the latest tools (Trello - JIRA - ClickUp - CodeMagic - Git - Slack ..etc) ✅ Understanding Patterns: MVC, MVVM, Delegate, Notification ✅ Singleton, Clean architecture, Dependency Injection ✅ Multi Threads App (Excellent Speed & Stability from the lowest device to the good ones) ✅ Unit testing / Mockito
Kotlin
FlutterFlowJetPackMobile AppAndroid SDKFirebaseAndroid App DevelopmentMobile App DevelopmentFirebase Cloud FirestoreJavaDartAndroidiOSSwiftUIFlutter - $50 hourly
- 5.0/5
- (1 job)
In 2012, I wrote my first Android app from start to finish. In 2015, I published a hobby project called Dual SIM Switch Widget and was pleasantly surprised when it quickly garnered over 100,000 installs. Since then, I've worked independently on various projects, such as a job listings aggregator, electoral toolkits, two bulk SMS messengers, and a daily routine app, handling everything from UX to databases to backend. What sets me apart? My knack for pinpointing and eliminating weaknesses in products, coupled with a relentless pursuit of performance optimization. My web apps consistently score 95+/100/100/100 on Lighthouse, commonly running on Debian bare metal that I configure myself.
Kotlin
Software Architecture & DesignProduct DesignProject ManagementCloudflareNGINXPage Speed OptimizationGolangAndroidPostgreSQLMySQLSQLiteJavaScriptPHP - $49 hourly
- 5.0/5
- (15 jobs)
I'm a Java-developer with 7+ experience in building enterprise applications. Working for the customer, I have 100 percent success and solve problems in the shortest possible time. My skill set includes technologies for backend: ⭐Spring ⭐Hibernate ⭐SQL ⭐Kotlin ⭐Apache Tomcat ⭐Jboss ⭐Maven ⭐Gradle Frontend: ⭐Angular ⭐Typescript ⭐Vaadin DevOps: ⭐Jenkins ⭐Teamcity ⭐uDeploy ⭐Kubernetes ⭐Openshift ⭐Linux ⭐Bash ⭐Python ⭐Groovy Also I developed several applications from scratch: ⭐Telegram bot for real estate searching ⭐Telegram game: text RPG-game ⭐Spring-boot application for working with customer ⭐Android puzzle game I am ready to work and develop professionally, contributing to the growth of your organization.
Kotlin
VaadinOpenShiftDockerDatabaseJSONPythonLinuxTelegram APILoad TestingAngularSQLHibernateSpring FrameworkJava - $70 hourly
- 5.0/5
- (17 jobs)
More than ten years of software development experience, including extensive work with Android's NFC (HCE+MIFARE), Bluetooth, BLE & Cryptography APIs. The most recent example of my work is Kisi's Android app (Kisi is a well-known provider of access control systems): ✅ The application was rearchitected from the ground up following the Clean Architecture guidelines; ✅ I did several sub-projects related to client-specific hardware, including but not limited to BLE, NFC, and Beacons-specific work; ✅ I also performed a refactoring of the big chunk of firmware which communicates with Android devices and secure NFC cards (MIFARE DESFire product family); ✅ I've introduced the number of initiatives aimed at increasing the project's health - setting up CI/CD, adding a suite of automated tests and code quality checks, and so on. The results speak for themselves - currently, the Kisi Android app is one of the most highly ranked access control apps in the Google Play market. Some keywords that may help you find me: Architectures: Clean/VIPER, MVP, MVVM, MVI - you name it Languages: Java, Kotlin, Dart Tests: JUnit, Espresso, Robolectric, Mockito CI/CD: Bitrise, Github Actions Connectivity: BLE, NFC HCE, extensive work with NFC tags (MIFARE cards and similar ones), iBeacon Miscellaneous: Android Architecture Components, Wear OS, RxJava, Kotlin Coroutines, Blinkup SDK, and many, many more.
Kotlin
GitNFCRxJavaAndroid App DevelopmentTabletSmartphoneApplication SecurityJavaAndroidFirebaseNative App Development - $50 hourly
- 5.0/5
- (15 jobs)
10+ years of experience in mobile app development, with a focus on designing, building, and maintaining cross-platform applications using React Native and its popular libraries. Proven expertise in delivering high-quality, clean code with a commitment to on-time delivery and excellent communication. Skilled in integrating AI technologies such as ChatGPT, Claude, Copilot to optimize development processes, debug efficiently, and enhance app functionalities. Extensive experience working with Firebase for backend services and analytics, as well as Strapi for content and API management. Key accomplishments include creating scalable, user-friendly applications for Android and iOS, leveraging popular React Native libraries like Redux, React Navigation, and Axios for seamless state management, navigation, and API integration. Proficient in optimizing performance and providing a smooth user experience. Technical Proficiencies: Mobile Development: React Native, JavaScript, TypeScript. Popular Libraries: Redux, React Navigation, Axios, Reanimated, and NativeBase. AI Integration: ChatGPT, Claude, Copilot. Backend Services: Firebase, Stripe API. DevOps & Hosting: Docker, Kubernetes, AWS, Google Cloud, Digital Ocean. Portfolio Highlights: Cross-platform mobile apps for e-commerce, health, and fintech. AI-powered features integrated into React Native applications. End-to-end mobile app solutions with optimized performance and modern design. Looking to contribute to innovative and challenging long-term projects in mobile app development using React Native.
Kotlin
QMLMobile App DevelopmentNative App DevelopmentObject-Relational MappingBoostWindows App DevelopmentAndroid NDKDesktop ApplicationJavaC++Qt FrameworkPythonLinux - $45 hourly
- 4.7/5
- (60 jobs)
Hello, My name is Nikola Djokic, and I am a software engineer with more then 10 years of experience. In last nine years I have been focused on Mobile platforms, Android in particular. After spending last four years in corporate environment as Tech Lead on multi milion dolar project, I am now back to freelancing, and consulting. I can offer wide range of services, from working solo, to engaging my network of associates and running more complex projects from idea to publishing and further. I hope that we will work together! Nikola
Kotlin
Video StreamMobile AdvertisingEngineering ManagementAndroid App DevelopmentiOS DevelopmentMobile App DevelopmentAndroidJavaProduct Management - $40 hourly
- 4.8/5
- (57 jobs)
✅ Upwork Top Rated Plus & Verified Mobile Developer As an expert developer with 10+ years of experience in mobile application development, one of my most-respected qualities is the ability to find solutions to any problem. In addition, I am committed to open and ongoing communication with my clients, as this is key to every successful project. All of my projects have contributed to the growth and development of my clients’ businesses and significant increases in their profits. Flutter Skills: Bloc, Riverpod, Go Router, RxDart, GetIt, Pusher, Stacked, Dio, Mobx Android Skills: Kotlin, Java, RxJava, Dagger2, ButterKnife, LiveData, DataBinding, Room, OKHttp, Retrofit, Volley. My advantages: • World-class quality and experience • 24/7 support • Bug-free guarantee through comprehensive testing • Timely delivery • Scalable and clean architecture • 100% money-back guarantee
Kotlin
FirebaseAndroid App DevelopmentJavaiOS DevelopmentDartNFCFlutterSmartphoneObjective-CSwiftAndroid - $10 hourly
- 5.0/5
- (11 jobs)
Projects that I have worked on are: Upgrading construction of solar panel for gaining more energy and prolonging the life of solar panel Upgrading drone for private use of getting data from air Production of technical details and sections in construction for exterior design
Kotlin
CSSAndroidCData EntrySketchUpHTMLAdobe PhotoshopMicrosoft OfficeAudacityJavaScriptPHPPythonC#SQL - $34 hourly
- 0.0/5
- (0 jobs)
OBJECTIVE Remote-savvy Android Developer with over 10 years of experience in software development and 4+ years specializing in Android mobile apps. Skilled in delivering high-quality native applications using Kotlin and Java within fully remote and distributed teams. Proficient in Agile methodologies, self-driven, and highly adaptable to changing priorities and cross-time-zone collaboration. Enthusiastic about clean architecture, performance optimization, and learning new technologies (including Declarative programming). Ready to bring value from day one. TECHNICAL SKILLS Android Development: Java, Kotlin, Jetpack Compose, Activities, Fragments, Services, Broadcast Receivers, Firebase, Google Maps, App and Dynamic Links. Libraries & Frameworks: Hilt, Coil, Picasso, Retrofit, Volley, Work Manager, Job Scheduler, SMS User Consent API, Text-to-Speech Architectures & Patterns: MVP, MVC, MVI, Clean Architecture, SOLID, Abstract Factory, Builder, Adapter Tools: Android Studio, Git, Swagger, Jira, Wireshark, TFS, Teams, Visual Studio Web Services & Databases: REST, SOAP, MS SQL, PostgreSQL Languages: Java, Kotlin, C#, Delphi, SQL, Turbo C SOFT SKILLS Self-motivated, detail-oriented, excellent communicator, creative problem solver
Kotlin
SOAP APIRESTful APIGitAndroidJavaC# - $25 hourly
- 5.0/5
- (1 job)
I prefer to work in Webflow, because this tool allows me to show my best side and to provide the client with maximum quality service.
Kotlin
Docker ComposeDockerRabbitMQSphinxElasticsearchClickHousePostgreSQLMySQLAngularJavaScriptSpring BootJavaLaravelPHP - $50 hourly
- 0.0/5
- (0 jobs)
I am a Software Development Engineer in Testing specialising on developing services to make test automation as smooth as possible (preparing test data and test environments, collecting metrics, setting up pipelines, etc.) I've been working in this field for more than 6 years, both writing tests myself and setting them up for others to write. I enjoy both learning things myself and teaching others. I have some experience in writing articles as well as giving talks and I have all intentions to get more experience in these areas.
Kotlin
Test StrategyTestNGUnit TestingJUnitTest-Driven DevelopmentTest Automation FrameworkContinuous IntegrationSpring BootJavaTest AutomationBack-End Development - $50 hourly
- 0.0/5
- (0 jobs)
Experienced Android Developer specializing in Kotlin, Java, Jetpack Compose, Retrofit.. I develop helper applications for Android STB devices and enjoy building innovative mobile apps in my free time. Proficient in Jenkins, Docker, Kubernetes, scripting, and software testing, I ensure scalable, efficient, and high-quality solutions for every project. Additionally, I have experience working with databases, Vue.js, Django (Python), and JavaScript. Let’s work together to bring your ideas to life!
Kotlin
Quality AssuranceApache GroovyJavaScriptPythonDockerVue.jsAlgorithmsTestRailGitJenkinsATVJavaSoftware QAAndroid App Development - $25 hourly
- 5.0/5
- (5 jobs)
As a seasoned AI/ML Solutions Architect and Intelligent Process Automation Specialist with over eight years of expertise, I excel in designing and implementing cutting-edge AI solutions that integrate machine learning, data science, and automation frameworks. My core competencies include developing enterprise-grade AI architectures, leading cross-functional teams in deploying scalable ML solutions, and leveraging cloud platforms like AWS, Azure, and Google Cloud to drive business growth through AI-powered tools such as LangChain and TensorFlow Extended. *******I DO WHAT I COMMIT AND I COMMIT WHAT I CAN DO******* 👉 What I Offer: As a seasoned AI/ML Solutions Architect and Intelligent Process Automation Specialist, I offer: ✔Expertise in designing and implementing enterprise-grade AI architectures using TensorFlow, PyTorch, and cloud platforms (AWS, Azure, GCP). ✔Proficiency in leveraging cutting-edge tools like LangChain for NLP and TensorFlow Extended for end-to-end ML pipelines. ✔Experience with big data technologies like Hadoop, Spark, and Apache Kafka for processing large-scale datasets. ✔In-depth knowledge of MLOps practices, ensuring seamless integration of AI solutions into existing IT infrastructure. ✔Expertise in advanced AI technologies such as natural language processing, computer vision, and reinforcement learning. *******I DO WHAT I COMMIT AND I COMMIT WHAT I CAN DO******* 👉 Key Skills: ✔Data Science & Analytics : Data Preprocessing, Statistical Modeling, Exploratory Data Analysis(EDA), PowerBI, Tableau, Hadoop, Apache Spark, Apache Kafka, SnowFlake, R, SQL. ✔AI Frameworks and Libraries : TensorFlow, Keras, PyTorch, Scikit-learn, Hugging Face, NLTK, LlamaIndex, SpaCy, OpenCV, Yolov8and so on. ✔Natural Language Processing (NLP) : Tokenization, Sentiment Analysis, Word/Sentence Embeddings, Text Classification, Text Generation, Conversational AI, Speech-to-Text, Retrieval-Augmented Generation. ✔Computer Vision : Image Classification/Segmentation, Object Detection/Recognition, GAN-based image synthesis, AI-powered Image Generation. ✔Automation Platform : Make.com, Zapier, N8N. ✔Web and Mobile Application Development : JavaScript/TypeScript Frameworks, React Next.js, Node.js, Express.js, Django, Python/FastAPI/Flask, MongoDB, MySQL, PostgreSQL, React Native, Flutter, Kotlin, Swift, Android, iOS, Google Play Store, App Store. *******I DO WHAT I COMMIT AND I COMMIT WHAT I CAN DO******* 👉 Why Work With Me? I offer a comprehensive development approach and ensure that your project is not only functional but also scalable and user-friendly. My focus is on providing solutions that meet your business goals and increase user satisfaction. I always provide you seamless, reasonable and reliable development approach to meet deadline. If you are looking for an experienced developer, I am here for you. *******I DO WHAT I COMMIT AND I COMMIT WHAT I CAN DO*******
Kotlin
PythonData ScienceChatbotPredictive AnalyticsBlockchainMERN StackiOSiOS DevelopmentAndroidObjective-CFlutterSwiftReact NativeSmart Contract - $35 hourly
- 0.0/5
- (0 jobs)
Experienced Android Developer (mid-senior) with 9+ years of experience in diverse projects, mainly in developing mobile platforms and applications. Joined First Media Advance AG (FMA) in November 2015 as a member of the Mobile team in the position of Android Developer. Later in my career, I advanced to Android Team Lead and soon after to Leader of the entire Mobile team. Worked on various projects involving a wide range of technologies, from NFC chips and other device sensors to Ethereum blockchain and the implementation of ETH wallet. Skilled in identifying, analyzing, and resolving bugs, as well as in designing and implementing innovative solutions to improve user experience.
Kotlin
Material DesignXMLJetPackGoogle APIsJSONREST APIFirebaseJavaAndroid SDKAndroid StudioAndroid AppAndroidApp DevelopmentAndroid App Development - $33 hourly
- 0.0/5
- (0 jobs)
Experienced Android Developer (mid-senior) with 9+ years of experience in diverse projects, mainly in developing mobile platforms and applications. Joined First Media Advance AG (FMA) in November 2015 as a member of the Mobile team in the position of Android Developer. Later in my career, I advanced to Android Team Lead and soon after to Leader of the entire Mobile team. Worked on various projects involving a wide range of technologies, from NFC chips and other device sensors to Ethereum blockchain and the implementation of ETH wallets. Skilled in identifying, analyzing, and resolving bugs, as well as in designing and implementing innovative solutions to improve user experience (UX/UI)
Kotlin
JSONRetrofitMaterial DesignGoogle MapsGoogle AdsFirebaseXMLGoogle PlayRESTful APIAndroid SDKAndroidJavaAndroid StudioAndroid App Development - $30 hourly
- 5.0/5
- (19 jobs)
Hi, my name is Vladimir Bulgakov. All my life I am engaged in programming. The last seven years I have been developing computer applications for android. Before that I was doing web sites using php. I have a degree from the Computing Center of the Siberian Branch of the USSR. After graduation, I developed the software for the construction industryy: lifting equipment selection automation, work schedules, registration and cancellation of materials. I have extensive experience in programming, including the last six years I have been developing Android applications. I like Android because it is really exciting developing for such small but powerfull devices. Programming languages and tools: Android SDK, Google Play Services, Fragment API Java Core, Kotlin, OkHttp, RxJava, Git, JavaScript, php, jQuery Html, SQL I enjoy programming and developing new appications.
Kotlin
Core JavaAndroid SDKAndroid App DevelopmentJavaScriptPHPCSSGitjQuery MobileAndroid - $10 hourly
- 0.0/5
- (0 jobs)
I'm student at University of Electrical engineering in Belgrade, and I would like to start freelance so I can get money and experience. Knows HTML, CSS, Python (Django) for web development. Knows C, C++ for system programming. Knows Java for desktop applications
Kotlin
AndroidDjangoPythonVue.jsJavaScriptC++CJava Persistence APIJavaFXJava GUIJava - $40 hourly
- 0.0/5
- (0 jobs)
I am a results-driven Full-Stack Web and Android Developer with over 7 years of experience building scalable, high-performance applications. I specialize in Java, Python, AWS, and cross-platform development, delivering robust solutions that align with business goals. Whether you need a dedicated full-time developer or a freelance expert, I bring technical excellence, clear communication, and a problem-solving mindset to every project. - What I Offer ✔ Custom Web Development – React, Angular, Vue ✔ Android & Mobile Development – Kotlin, Java, React Native ✔ Scalable Backend Solutions – Node.js, Django, Spring Boot, .NET ✔ Cloud Infrastructure & DevOps – AWS, RESTful APIs ✔ Database Architecture – MySQL, PostgreSQL, MongoDB ✔ End-to-End Project Management – Agile, Jira, Trello, Asana ✔ Third-Party API Integration – Stripe, Twilio, Firebase, AWS Lambda - Tech Stack ✔ Frontend: HTML, CSS, JavaScript, React, Angular, Vue ✔ Backend: Node.js, Django, Spring Boot, .NET, PHP ✔ Databases: MySQL, MongoDB, PostgreSQL ✔ Mobile: Android SDK, Kotlin, Java, React Native ✔ Cloud & DevOps: AWS (Amazon Web Services) - Why Work With Me? ✔ Client-Centered Approach – I focus on delivering solutions that meet business needs. ✔ Scalability & Performance – Every project is optimized for speed, security, and future growth. ✔ Clear & Professional Communication – I ensure transparency at every stage of development. ✔ On-Time Delivery – I am committed to meeting deadlines without compromising quality. 📩 Let’s bring your vision to life! Contact me to discuss your project.
Kotlin
PostgreSQLSpring BootAWS AmplifyReact NativeAndroid SDKMongoDBMySQLPHPDjangoNode.jsReactJavaScriptCSSHTML - $12 hourly
- 4.8/5
- (4 jobs)
Dear Sir/Madam, First of all, I would like to thank you for considering me as your future employee. If you are in need of a certified Android Application Developer, I am the right person for you. With my experience, I can help you accomplish your business goals. I have experience in Kotlin, Java, Firebase, Android SDK and basic knowledge of Flutter Being dedicated and punctual, I hope you will find me suitable for the job. Pay rates are negotiable and usually depend on the type of the job. Quick responses, fast-paced yet detailed work are the words that describe me the best because client contentment is of utmost importance to me. Check my Portfolio section for details on projects I have been working on. I am looking forward to working with you, Daniel
Kotlin
SQLite ProgrammingAndroid SDKAndroid App DevelopmentRESTful ArchitectureAndroidJavaFirebaseAndroid Studio - $5 hourly
- 0.0/5
- (0 jobs)
I am a dedicated Software Engineer with expertise in Android app development, full-stack web development, and AI-driven solutions. My passion lies in creating innovative and scalable applications that solve real-world problems. What I do best: Android Development: Skilled in Kotlin, Firebase Firestore, and RESTful services, I have developed user-friendly applications, including a travel planner app as part of my thesis. Full-Stack Development: Proficient in building robust solutions using Spring Boot for back-end services and Next.js for responsive front-end interfaces. AI Projects: Leveraged machine learning models like Random Forest and Neural Networks for weather prediction and image classification projects. Database Management: Solid understanding of relational (PostgreSQL, MySQL) and NoSQL databases (Firebase). I thrive in team-oriented environments, continuously learning and adapting to new technologies to deliver exceptional results. Let’s collaborate and create something impactful together!
Kotlin
Software Architecture & DesignMariaDBPostgreSQLOracle APEXMySQL ProgrammingSpring BootTypeScriptNext.jsJavaWeb ApplicationWeb DevelopmentApp DevelopmentAndroid App Development Want to browse more freelancers?
Sign up
How hiring on Upwork works
1. Post a job
Tell us what you need. Provide as many details as possible, but don’t worry about getting it perfect.
2. Talent comes to you
Get qualified proposals within 24 hours, and meet the candidates you’re excited about. Hire as soon as you’re ready.
3. Collaborate easily
Use Upwork to chat or video call, share files, and track project progress right from the app.
4. Payment simplified
Receive invoices and make payments through Upwork. Only pay for work you authorize.
Trusted by
How do I hire a Kotlin Developer near Belgrade, on Upwork?
You can hire a Kotlin Developer near Belgrade, on Upwork in four simple steps:
- Create a job post tailored to your Kotlin Developer project scope. We’ll walk you through the process step by step.
- Browse top Kotlin Developer talent on Upwork and invite them to your project.
- Once the proposals start flowing in, create a shortlist of top Kotlin Developer profiles and interview.
- Hire the right Kotlin Developer for your project from Upwork, the world’s largest work marketplace.
At Upwork, we believe talent staffing should be easy.
How much does it cost to hire a Kotlin Developer?
Rates charged by Kotlin Developers on Upwork can vary with a number of factors including experience, location, and market conditions. See hourly rates for in-demand skills on Upwork.
Why hire a Kotlin Developer near Belgrade, on Upwork?
As the world’s work marketplace, we connect highly-skilled freelance Kotlin Developers and businesses and help them build trusted, long-term relationships so they can achieve more together. Let us help you build the dream Kotlin Developer team you need to succeed.
Can I hire a Kotlin Developer near Belgrade, within 24 hours on Upwork?
Depending on availability and the quality of your job post, it’s entirely possible to sign up for Upwork and receive Kotlin Developer proposals within 24 hours of posting a job description.