Dear Sir or Madam, My name is Oleksandr Prognimak. I have been working as a software developer for 33 years. I have extensive and longstanding experience in the following programming languages, frameworks, libraries, and technologies. Currently, my main focus is on the following IT areas: Java, JEE, Spring, Spring Boot, Angular, HTML5, JavaScript, TypeScript, CSS, SQL, PL/SQL, Docker, JUnit, Mockito, WireMock, Pact io, Maven, Oracle, PostgreSQL, and Azure Cloud. Here is the complete list of my skills: Skills, consulting, and development as a freelancer in the following areas: - Java: JDK 1.1 - 21, JSE, Swing, AWT - JEE: J2EE, JEE5,6,7,8,10 (Servlet, CDI, EJB, JPA, JMX, JMS, JSF) - Spring/Spring Boot: Spring Core, Spring Boot, Spring Test, Spring Data, Spring Integration, Spring Batch, Microservices - Cloud: Azure, AWS - Web Development/UI: Angular 4,7,10,16; Vue.js 2,3; TypeScript, GWT, Vaadin, JSP, JSF (RichFaces, PrimeFaces), HTML4, HTML5, JavaScript, JQuery, AJAX, Struts, Spring MVC - Web Services: SOAP, SOA, RESTful, Rest-API, OpenAPI, Swagger, RestEasy, Jersey, JSE HttpClient - ORM: Hibernate, EclipseLink, Apache OpenJPA - RDBMS/SQL: Oracle, Postgres, MySQL, MS-SQL, SQL, PL/SQL, MS Access, Teradata, H2 - App. Server/Servlet Container: Apache HTTP, Apache Tomcat, JBoss, Wildfly, Websphere, OC4J - XML Processing: AXIS-2, XPath, XSLT, XML Schemas, JAXP, JAXB - Build Tools: ANT, Maven, Gradle, Mojo - Source Code Management: GIT, GitLab, GitHub, Bitbucket, SVN, CVS - Case Tools/UML: Magic Draw, Software Architect, Together, ERWin, RationalRose - Report Tools: Jasper Report, BIRT Reports, Oracle Forms and Reports, Eclipse BI-Reports - Security: Java Security, JSSE, PKI, Websecurity, X509 - Test Tools/Testing: JUnit, TestNG, Cucumber, JBehave, Mockito, WireMock, EasyMock, Spring Test, Pact io, LoadTest, IntegrationTest, CI - MS-Office: VB, VBA, Excel-VBA, Access-VBA - Container Virtualization: Docker, Docker-Compose, Swarm, Kubernetes (K8) - Big Data: Apache Kafka, Zookeeper - Very Old Skills: C, C++, Basic, Pascal I am available immediately. Best regards, Oleksandr Prognimak

I have 15 years of professional experience in software development, backed by a Bachelor’s degree in Computer Science Engineering. I specialize in building scalable, high-performance applications using Java and Spring Boot, with strong expertise in designing robust backend systems and microservices architectures. I have extensive experience working with AWS, leveraging cloud-native services to develop secure, reliable, and cost-efficient solutions. Additionally, I have been actively involved in AI technologies, integrating intelligent capabilities into applications to drive automation, enhance decision-making, and improve user experience. With a solid academic foundation and diverse technical skill set, I contribute effectively across the full software development lifecycle, from system design and development to deployment and optimization. I am committed to continuously learning and applying modern technologies and best practices to deliver innovative solutions.

🥇Java, Spring Boot, JavaScript, Python, Architecture, Design, API, Healthcare, RDBMS, SQL, NoSQL, ETL, Data Warehouse, FHIR, Agentic Coding🥇 I love software engineering 😊 and I can help you build quality cloud / SaaS applications 🚀 ⚙Services: Software Development, Engineering Research and Design 🛠Technologies: Java, Spring, Python, JavaScript, SQL/NoSQL, Microservices, REST/SOAP, and more. 🕴Industries: ✅ HealthTech (LIS, HIS, HL7, FHIR, CMS) ✅ Cloud (Azure, AWS, GCP) ✅ FinTech (Retail, Investment, Wealth Management, Custodian Banking) ✅ E-Commerce ⬅️ Watch my intro video to learn more. I'm looking for long-term cooperation. But we can discuss short-term projects too. Do you need a team of devs to build or maintain a project for you? Drop me a message, and I will help you.

I help clients solve real business problems through technology by building reliable, scalable, and practical software solutions. Backend development is my core strength, with 10+ years of experience in Java, Spring Boot, REST APIs, microservices, and enterprise systems. I can also contribute on the frontend when needed, which allows me to handle the complete software lifecycle—from requirement gathering and solution design to development, testing, and deployment. What I can help you with: Java and Spring Boot backend development REST APIs and microservices Enterprise application development Oracle, MySQL, and database-driven systems Full software lifecycle delivery, from requirements to deployment Frontend support when end-to-end execution is needed In addition to strong technical expertise, I bring domain experience across fintech in Pakistan and Cameroon, healthcare and fitness in Europe, and trucking and agriculture in the USA. I have worked on systems where strong architecture, clean business logic, and dependable delivery are essential. My focus is always on understanding requirements clearly and delivering solutions that are maintainable, efficient, and aligned with business goals. I value clear communication, professionalism, and honesty throughout every stage of the project.

Greetings! I am a Java Developer with 4 years of experience in Tech. My skills & abilities allow me to cover all aspects of Back-End development: design and develop a robust Back-End part, and then cover the product with Unit Tests. Due to my profound background in app development for industries like Electric Vehicle Charging, I prefer complex and meaningful projects. Invite me for an interview if you feel like I’m the right person to turn your ideas into reality. TECHNOLOGIES I USE ✅ PROGRAMMING LANGUAGES: Java, SQL ✅ FRAMEWORKS: Spring (Spring Data, Spring Boot, Spring Security), Hibernate ✅ DATABASES: MySQL, JDBC, Hibernate ✅ WEB: Servlets, JPS, Tomcat ✅ TESTING: JUnit ✅ Operating systems: Windows, Linux, Unix ✅ OTHER: Docker, Maven, Git, OCPP 1.6 In addition to the above, I possess a solid grasp of Algorithms and Data Structures. Also, I have extensive Functional Testing and Unit Testing skills. API Integration is also among my strongest sides. MY MOST RECENT PROJECTS ✅FinTech system: The main purpose of the system is to simplify the communication between banks and retail customers who want to get a loan for buying goods. The staff at the retail shops use the system to distribute the buyer’s data across multiple banks. That is done to see which bank will accept the buyer’s loan application at the most optimal conditions. I'm worked on the improvement of the existing codebase; integrated the APIs of multiple banks single-handedly; insured the high quality and full test coverage of the codebase ✅EVCS sharing platform for the Swedish company: A platform consists of 2 parts: the first one is for the owners of the Electric Vehicle Charging Stations, who have installed them and would like to open them for the public in order to gain additional profit; the second one is a mobile app for the drivers who would like to navigate to the available chargers nearby, manage the charging process, and pay for charging. On this project, I performed as a Back-End developer. I'm worked on the improvement of the existing codebase; integrated different payment systems & EV Charging station vendors; was responsible for new feature development LANGUAGES I SPEAK Ukrainian is my native language. Besides, I have strong English skills. Most of my previous customers were English-speaking, so I am comfortable communicating in English. MY TEAM I am at ease as an individual contributor, but being a team player works best for me. So I joined Extrawest — an Upwork Top Rated Agency specializing in FinTech and Banking, Gambling and Betting, Food Ordering and Delivery, Logistics and Fleet Management, Medical Insurance and Healthcare, and special software for Electric Vehicles Charging Station networks since 2006. Having most of our resources based in Europe, we’ve been working with customers from over 20 countries (the US, Canada, Australia, most of the EU, South Africa, Singapore, Japan). Hence, it won’t be a problem for us to adjust to your timezone and working schedule. INVITE ME FOR AN INTERVIEW If you feel I’m a perfect match for your project, let’s set up a call, discuss your ideas and streamline your business’s growth! 🟩 🟩 🟩 🟩 My Agency Skills: Front-End (Frontend) Development, Back-End (Backend) Development, Full-Stack (Fullstack) Development, Mobile Development, EV Charging, Automotive, Logistics, Delivery, Food Ordering, FinTech, Finance, Banking, Dashboard, Healthcare, Insurance, Betting, Gambling, Data Scraping, Flutter, Dart, JavaScript (JS), TypeScript (TS), Angular, Vue.js (VueJS, Vue), React.js (ReactJS, React), Node.js (NodeJS, Node), Java, Spring, SpringBoot, Hibernate, Python, Django, Scrapy, Quality Assurance (QA), Manual Testing, Automated Testing, Selenium, UI/UX Design, User Interface (UI), User Experience (UX), Figma, Adobe Creative Cloud, DevOps, MySQL, PostgreSQL, MongoDB, Firebase, Docker, Amazon Web Services (AWS), Google Cloud Platform (GCP), Project Management (PM).

If you're building a serious product and need it done right the first time you're in the right place. I’m a Senior Full Stack Java Developer with 10+ years of experience designing and building scalable, high-performance applications using Spring Boot, Microservices, and modern frontend frameworks like React and Angular. I don’t just write code I help you architect, build, and scale systems that are production-ready and future-proof. 💼 What I Can Help You With: ✔️ Design & development of scalable backend systems (Spring Boot, Microservices) ✔️ Building secure, high-performance REST APIs ✔️ Full-stack development with React / Angular ✔️ System architecture & database design for long-term scalability ✔️ Cloud deployment on AWS (EC2, S3, RDS, Lambda) ✔️ Performance optimization & code refactoring ✔️ Third-party API integrations (payments, messaging, etc.) 🧠 Modern Edge (AI + Automation) I also help businesses leverage AI to improve workflows and products: • OpenAI / ChatGPT integrations • LangChain-based automation & document processing • Workflow automation using Zapier / Make • AI-powered features (chatbots, search, RAG systems) ⚙️ Tech Stack (Focused & Relevant) Backend: Java, Spring Boot, Spring Security, Microservices Frontend: React, Angular, JavaScript, TypeScript Database: PostgreSQL, MySQL, MongoDB, Redis Cloud & DevOps: AWS, Docker, Kubernetes, CI/CD Messaging: Kafka, ActiveMQ 💡 Why Clients Work With Me: • I write clean, maintainable, production-grade code • I think like an architect, not just a developer • I communicate clearly and don’t disappear mid-project • I focus on long-term value, not quick fixes If you’re looking for someone reliable who understands both business and technology, let’s talk.

💡 I help you fix backend issues fast, stabilize live systems, and build reliable APIs that work under real-world load. 💡 I also work on Java + Angular/TypeScript full-stack bugs, especially issues involving existing codebases, state handling, API flows, auth, and cross-platform app behavior. 💡 I fix rough MVPs and broken code produced by Claude, Codex, Cursor, and other AI agents: fragile flows, messy handoffs, weak auth, API bugs, browser-extension issues, and code that works in a demo but breaks in real use. 💡 I can also build focused MVPs/prototypes in hours when the scope is clear, then clean them up so they are maintainable. With 15+ years of hands-on experience, I’ve worked across enterprise systems, production debugging, high-availability applications, and government-grade Java/Spring Boot platforms. I’m not just building features; I’m usually the person called when something is already live, complex, slow, or broken. What I can do for you: * Debug and fix backend issues quickly (APIs, async flows, database problems) * Fix frontend issues in Angular, TypeScript and JavaScript (UI bugs, API integration issues, state handling) * Fix AI-generated / Claude / Codex / Cursor code before handoff * Clean up fragile MVPs and turn them into maintainable software * Debug browser extension issues and extension-to-backend connection problems * Optimize slow queries and improve performance (MySQL, SQL Server, Oracle) * Build and improve REST APIs (Java Spring Boot, Node.js) * Integrate third-party APIs (OAuth, OIDC, secure integrations) * Stabilize production systems and reduce recurring issues * Build focused MVPs and internal tools using Java, Node.js, Angular, APIs, and AI-assisted development * Automate workflows using scripts and AI agents where it makes sense * Set up and troubleshoot Linux-based environments (dev tools, services, remote access) * Configure browser-based dev environments (code-server / VS Code in browser) * Secure access using Cloudflare Tunnel or similar approaches (no port forwarding / VPN) * Fix and enhance C# desktop applications, including UI controls and small DevExpress tasks * I also handle structured document and data transformation work, including XML/schema-based outputs, PDF/Word-to-structured-data conversion, validation-driven formatting, and automation around repetitive document workflows. My approach is practical: understand the target schema, convert carefully, validate the output, and deliver clean files that are easy to review and maintain. Tech I work with regularly: * Backend: Java, Spring Boot, Node.js, Python (automation/scripts) * Frontend: Angular, TypeScript, JavaScript, HTML/CSS * Databases: MySQL, SQL Server, Oracle, Redis * APIs: REST, SOAP, API integrations, authentication flows * Reporting: JasperReports / Jaspersoft Experience highlights: * 6+ years at Upland Software on PowerSteering PPM, delivering 20+ product features and fixing 100+ defects in a mature enterprise product * Lead Java/full-stack work on Dubai Government projects, including DubaiNow integrations and the Dubai Police Rain and Waterlogging Forecast System * Architected or contributed to 20+ telecom and financial transaction systems before moving fully into remote enterprise product work * Strong focus on debugging, performance tuning, and understanding complex existing systems quickly I’m not here just to write code. I focus on solving problems, especially in systems that are already live and need careful handling. If your system has an issue, your AI-built MVP needs cleanup, or you need someone who can jump in, understand it fast, and fix it properly, I can help.

🥇 TOP RATED | 👨🏻‍💻 500+ WORKING HOURS | 💼 7+ YEARS EXPERIENCE | 🏆 100% Job Success | 🇦🇪 Based in Dubai UAE ⭐️⭐️⭐️⭐️⭐️ "I highly recommend Mohamed, he is the perfect freelancer, always available, very proactive, and with outstanding experience in Java. I think you can't find better" ------------------------------------------------------------------------------ ⭐️⭐️⭐️⭐️⭐️ "Very knowledgeable in Java and quickly came up with a solution. Will reach out again for Java-related work." ------------------------------------------------------------------------------ ⭐️⭐️⭐️⭐️⭐️ "A great person and a great developer. Fawzy is a real asset to the project, a great help to the rest of the team, able to "get on with the job" and make things happen!" ------------------------------------------------------------------------------ ⭐️⭐️⭐️⭐️⭐️ If you're looking for the top 3%, Mohamed IS your candidate. ” “ Having worked with Mohamed for around 2 years in the same team, I can safely say he's a brilliant problem solver & I've met a few. If you ever have a technical chat with him, you can't help but notice "the spark". Not to mention that he's very supportive & a great team player. -- Linkedin Endorsement ------------------------------------------------------------------------------ ⭐️⭐️⭐️⭐️⭐️ “ Mohamed is such a great professional to work with. He has a strong knowledge and does not understand things from the surface, but he works and he understands things accurately and helps you to understand that during work, He is one of the best I've worked with and helps a lot non-stop I enjoyed working with him and I hope to work with him again ” -- Linkedin Endorsement ------------------------------------------------------------------------------ I'm Mohamed Hassaballa, a Senior software engineer with 7+ years of corporate experience delivering high-quality Backend/Frontend applications Serving millions of users, with perfect keenness to standards and best code practices / Design patterns, ** My main stack for backend development is: - Java "8 - 11", Spring, Spring boot, Spring data, Spring Cloud, Hibernate, Mysql, Redis, and Kafka ** I work with "VueJs, and ReactJs for Frontend Development, with proficiency in Frontend Markup "HTML/CSS" ** Tools I work with daily " Git "Bitbucket / Gitlab", IntelliJ, Jenkins ------------------------------------------------------------------------------ I can deliver all backend/frontend requirements in a business-aware manner, where I will focus on quality and cost at the same time, while business always changes, I can guarantee to deliver solutions that can be easily extended and maintained, with a complete focus on quality, delivery time and within suggested budget.

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.

🚀 Top 1% AI/ML & Full Stack Upwork talent specializing in scalable AI-driven applications, enterprise platforms, and intelligent automation systems. I help businesses build production-ready AI solutions that automate workflows, optimize operations, improve decision-making, and scale efficiently. From AI Chatbots, AI Agents, and RAG systems to enterprise backend architectures and full-stack SaaS platforms, I deliver secure, high-performance, and maintainable solutions tailored to real business needs. ➤ 𝗔𝗜 & 𝗠𝗟 𝗘𝘅𝗽𝗲𝗿𝘁𝗶𝘀𝗲 Python, NLP, Deep Learning (CNN, RNN, LSTM), Transformers, Prompt Engineering, AI Automation, Generative AI, LLMs (OpenAI, Claude, Gemini, Hugging Face, Llama 3), AI Agents, AI Chatbots, RAG Systems, Semantic Search, AI-powered SaaS Applications. ➤ 𝗔𝗜 𝗙𝗿𝗮𝗺𝗲𝘄𝗼𝗿𝗸𝘀 & 𝗧𝗼𝗼𝗹𝘀 LangChain, LangGraph, LlamaIndex, CrewAI, AutoGen, Pinecone, Weaviate, FAISS, PGVector, Hugging Face, Vector Databases, AI Workflow Automation. ➤ 𝗕𝗮𝗰𝗸𝗲𝗻𝗱 𝗗𝗲𝘃𝗲𝗹𝗼𝗽𝗺𝗲𝗻𝘁 Java, Kotlin, Spring Boot, Java Microservices, Python, FastAPI, Django, Flask, Node.js, NestJS, Express.js, REST APIs, GraphQL, Kafka, Redis, PostgreSQL, MySQL, MongoDB, Firebase. ➤ 𝗙𝗿𝗼𝗻𝘁𝗲𝗻𝗱 𝗗𝗲𝘃𝗲𝗹𝗼𝗽𝗺𝗲𝗻𝘁 React.js, Next.js, Angular, Vue.js, Redux, Tailwind CSS, Material UI, HTML5, CSS3, JavaScript, TypeScript. ➤ 𝗖𝗹𝗼𝘂𝗱 & 𝗗𝗲𝘃𝗢𝗽𝘀 AWS, GCP, Azure, Docker, Kubernetes, Terraform, Jenkins, GitHub Actions, CI/CD Pipelines, Serverless Architectures, Cloud Deployments. ➤ 𝗔𝘂𝘁𝗼𝗺𝗮𝘁𝗶𝗼𝗻 & 𝗜𝗻𝘁𝗲𝗴𝗿𝗮𝘁𝗶𝗼𝗻𝘀 n8n, API Integrations, Workflow Automation, Third-Party Integrations, AI-powered Automation Systems, CRM & SaaS Integrations. ➤ 𝗦𝗲𝗿𝘃𝗶𝗰𝗲𝘀 𝗜 𝗢𝗳𝗳𝗲𝗿 ✔ AI Chatbots & AI Agents ✔ LLM Fine-Tuning & RAG Systems ✔ AI-Powered SaaS Platforms ✔ Enterprise Backend Development ✔ AI Automation & Workflow Systems ✔ Full Stack Web Development ✔ API Development & Integrations ✔ Scalable Cloud-Based Applications ➤ 𝗜𝗻𝗱𝘂𝘀𝘁𝗿𝗶𝗲𝘀 𝗦𝗲𝗿𝘃𝗲𝗱 Healthcare • Fintech • E-commerce • Education • Logistics • Real Estate • Enterprise SaaS • Automation Platforms ➤ 𝗪𝗵𝘆 𝗖𝗹𝗶𝗲𝗻𝘁𝘀 𝗪𝗼𝗿𝗸 𝗪𝗶𝘁𝗵 𝗠𝗲 🤝 Clear & professional communication ⚡ Fast, reliable, and scalable delivery 🧩 Strong problem-solving mindset ✅ Clean, secure, production-ready solutions 📈 Focused on long-term business value I’m happy to provide recommendations tailored to your project requirements. Let’s connect and discuss how we can build a powerful AI-driven solution for your business.