Hire the Best Apache Developers in Prague, CZ

Senior Java Developer with 7+ years building production microservices and integration platforms for banking and financial systems. Based in Prague, Czech Republic, with an MSc in Informatics (Czech University of Life Sciences, 2025). I specialise in: • Backend Java (17/21) with Spring Boot 3.x, Spring Security, and Spring Cloud • Event-driven architecture using Apache Kafka and RabbitMQ • API design (REST/OpenAPI 3.x), Kong API Gateway, and MuleSoft integrations • Identity and security: Keycloak, OAuth 2.0/OIDC, HashiCorp Vault • Databases: PostgreSQL, Oracle, MongoDB — including live migration projects • DevOps: Docker, Kubernetes, Helm, GitLab CI/CD, GitHub Actions • Observability: OpenTelemetry, Prometheus, Grafana, Loki, Splunk • Testing: Testcontainers, JUnit 5, WireMock, Allure Report I deliver clean, well-tested, production-ready code and take full ownership from requirements through deployment. I work well in distributed teams across European time zones and communicate clearly in English. Available for backend Java projects, API development, system integration, and architecture consulting.

I worked on Upwork during it was still Odesk ( May 2011 - Aug 2013 ). After this, up until September 2018, I concentrated on JavaScript and Python. I developed front-end web applications using AngularJS, Bootstrap, HTML5, CSS3, ReactJS, jQuery, Webpack. As for back-end I worked with Django REST Framework. Also, I was developing back-end with PHP and Laravel framework. Now I am starting on Upwork again combining with my full time job.

I am a DevOps and Event Streaming Engineer with strong expertise in cloud infrastructure, CI/CD automation (Jenkins, Gitlab CI), containerization (Docker, Kubernetes), and real-time data streaming (Kafka, Pulsar). Beyond development (Java, Python, JavaScript), I specialize in designing scalable architectures and solutions on Kafka, ensuring efficient data flow, fault tolerance, and high availability for event-driven applications.

Thanks for looking at my profile. Please DON'T consider hiring me if: - you are looking for beginner/mediocre developer who will do the job for you as cheap as possible - think you are the smartest person in the universe (neither am I) - don't want to discuss/answer questions, share a wider context about your project. I want to provide my services as I if was your business partner - my work doesn't create more value for you than your investment in my work ------------------------------------------------------------- Here are feedbacks from my previous clients: "Everything was done perfectly." "Zdenko has strong Python coding expertise and good architectural knowledge of the Google Cloud Platform. He provided valuable architectural and project guidance. Zdenko was responsive provided excellent documentation with his insights that were valuable." Zdenko was a great developer to work with. He is very knowledgeable of Google Could Platform and understood the task which needed to be done without excessive guidance. I would highly recommend Zdenko to anyone looking to develop a data pipeline in the cloud. "Fantastic person and hard working! He delivered quality work and knew exactly what was needed to complete the job." Working with Zdenko was incredibly easy, and he produced exactly the results we were looking for. Communication was excellent via messaging on UpWork. I would highly recommend Zdenko. "Great Job! He knows GAE very well and was able to do everything we asked for. great python developer. yet again we are going to hire him immediately" "He let me know exactly what I needed to give him, and he didn't waste any time in getting it done. He also knew to do a couple of things that I didn't explicitly ask him to do when we started, but which clearly needed to be accomplished as part of the larger task." ------------------------- During my years as a software consultant, I have realized that communication with the client is most crucial. That's why I make every effort to understand the requirements of the task that's needed to be done, remove ambiguities, make a thorough analysis, suggest a solution, and implement. For several years now I'm focused on deploying web apps and big data pipelines on Google Cloud Platform and using its products (Google App Engine, Cloud Run, Cloud Functions, Google Compute Engine, BigQuery, Dataflow, etc). I write about it on my personal page and answer questions on Quora My expertise is in programming Python web/data applications. I use mostly Django, Flask, Webapp2 frameworks. Besides that, I have knowledge of other web technologies (HTML, CSS, Javascript...). I am very open to new challenges and problems. I prefer working on Linux. I am constantly improving my skills and knowledge in all areas. Experience with scrapping e-shops, real estate websites using BeautifulSoup I'm not a frontend guru, if necessary I can work with Bootstrap and a little bit of Javascript

I’m a technical QA engineer who finds issues before users do—across UI, APIs, and data. I write clear bug reports, validate complex flows, and build automation that reduces regression risk and speeds up releases. With ~10 years in Java and QA automation lead experience in product companies (iGaming), I’ve built custom, maintainable test frameworks and stabilized CI pipelines. I can help with: * Manual QA: functional/regression/exploratory testing, UX issues, release checklists * API & technical validation: Postman/RestAssured, JSON validation, logs/data checks * Automation: Selenium UI + API tests (JUnit/RestAssured, custom frameworks), Testcontainers, Allure, CI integration * Performance: JMeter/Gatling (optional) I’m happy to start manually and add automation where it gives the highest ROI. Open to a short paid trial (5–10 hours) to prove fit quickly.

Most developers build things. I fix them. When something breaks and nobody knows why, that's where I come in. I find the problem, fix it and you're back in business. 💥App crashing or acting weird - crashes for no reason, works differently on different devices, broken on mobile or some browsers, behaves strangely after an update. 💥App running slow - pages take forever to load, simple actions hang for too long, dashboards and reports are slow and painful to use. 💥Integration not working - app can't connect to another system, API stopped working after an update, two systems that simply won't talk to each other. 💥Vibe coded or can't deploy - AI-generated app nobody understands anymore, works locally but not on the server, agency left broken code behind and disappeared. 💥Old system - needs to move to a new platform, the company that built it is gone, old code nobody wants to touch but still needs new features. 💥Developer disappeared - left no documentation, nobody understands what is going on, project is stuck and nobody knows what to do next. 💥Security problems - app was hacked, serious security issues hiding in the code, private data got out and you need it fixed now. Sound familiar? I do not disappear. I do not hand you off to a junior. You get me, 20 years of experience, Expert-Vetted status and 100% Job Success. Every time. Not sure if I can help? Just tell me what is on fire. I will take a look and give you a straight answer. No "sugarcoating". Let's talk. ⚡ Programming Languages JavaScript, TypeScript, C#, Python, PHP, Java, PowerShell, Bash/Shell, VBA, C++, C, Assembly, HTML, CSS, SASS/SCSS ⚡ Application Frameworks Angular, React, Next.js, Vue.js, Node.js, .NET, ASP.NET, Gatsby, Express.js, Laravel, Remix, Astro, Svelte, Blazor, Electron, AG Grid ⚡ Databases SQL, MongoDB, MySQL, Microsoft SQL Server, PostgreSQL, Oracle, SQLite, Redis, Elasticsearch, Firebase Firestore, MariaDB, Microsoft Access ⚡ API REST API, GraphQL, WebSockets, gRPC, SOAP, OpenAPI/Swagger, WebHooks, SSE, JSON-RPC, XML-RPC, OData, API Gateway, tRPC, SignalR, CORS ⚡ Cloud Platforms Google Cloud Platform, Microsoft Azure, Amazon Web Services, Firebase, Vercel, Netlify, Supabase ⚡ DevOps Docker, Kubernetes, Jenkins, GitLab CI/CD, GitHub Actions, TeamCity, Nexus, Nginx, IIS, Terraform, Helm, Bitbucket Pipelines, Azure DevOps, OpenShift, Grafana, Chef ⚡ CSS Frameworks Tailwind CSS, Bootstrap, Material UI, Angular Material, HeadlessUI ⚡ Mobile Frameworks React Native, Apache Cordova, Capacitor by Ionic, Expo, Ionic ⚡ Testing Frameworks Playwright, Jest, Karma, Vitest, Jasmine, Cypress, Selenium, xUnit, NUnit, MSTest, Puppeteer, WebdriverIO, Storybook ⚡ Authorization OAuth, JWT, Auth0, Firebase Authentication, Passport.js, NextAuth.js, Azure AD, SAML, OpenID Connect, LDAP, Microsoft Identity Platform, AWS Cognito, Supabase Auth ⚡ Database Frameworks Entity Framework, Prisma, Mongoose ⚡ Logging ELK Stack, Log4net, NLog, Serilog, Logstash ⚡ Integrations Stripe API, Google Maps API, Firebase API, GitHub API, GitLab API, n8n, Apache Kafka ⚡ Architecture Microservices, Monolithic, Event-driven, Serverless, Headless, MVC, MVVM, Domain-Driven Design (DDD), CQRS, SOA, Dependency Injection (DI), Inversion of Control (IoC), SOLID principles, Design Patterns (GoF) ⚡ AI Tools GitHub Copilot, GitHub Copilot CLI, Claude, Claude Code, Gemini, Gemini CLI, Ollama, ChatGPT, Codex ⚡ Machine Learning PyTorch, TensorFlow, Keras, Scikit-learn, Pandas, NumPy, Jupyter Notebook, Kaggle, Hugging Face ⚡ Code Quality ESLint, Prettier, SonarQube, StyleLint, TSLint, ReSharper, StyleCop, Roslyn Analyzers, Pylint ⚡ Package Managers npm, yarn, pnpm, NuGet, pip, Homebrew, Maven, Gradle, UV, apt, yum, Chocolatey, winget ⚡ IDEs VS Code, Visual Studio, IntelliJ IDEA, PyCharm, Vim, Xcode ⚡ Operating Systems Windows, Linux, macOS, Android, iOS