Hire the Best Object Oriented Programming (OOP) Specialists

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Vasyl S.

Lviv, Ukraine

$50/hr
4.3
40 jobs

Senior Full-Stack Developer • Performance Optimization Expert Java, Kotlin, JavaScript (frontend/backend), C++, Python, PHP, Perl SQL/NoSQL, Web/Desktop apps, Automation, Web Scraping I help companies make their software faster, lighter, and more efficient. 20+ years of hands-on experience in system performance tuning, profiling, solving bottlenecks, and refactoring legacy systems. If your application is slow, unstable, memory-hungry, or needs deep analysis — I can fix it. ⸻ 🧩 My Core Expertise • Performance optimization (Java/JVM, databases, backend services) • Query optimization, memory leak detection, code profiling • Refactoring legacy code, stabilizing old systems • Full-stack development (Java/Kotlin + JS, Python, PHP, Perl, C++) • Web automation & scraping • Systems analysis, debugging, complex issue resolution ⸻ 🚀 What I Deliver • Faster request processing • Reduced memory & CPU usage • Significantly improved database performance • Clean, maintainable, well-structured code ⸻ 🤝 Availability Open to long-term or part-time collaboration (30–40 h/week). Also interested in innovative startups: your idea — my implementation. ⸻ Let’s make your software fast, stable, and scalable!

  • MongoDB
  • PHP
  • JavaScript
  • Data Scraping
  • AJAX
  • Apache Maven
  • Java
  • System Analysis
  • RESTful API
  • Perl
  • CSS
  • jQuery
  • Apache Tomcat
  • Spring Boot
  • MySQL Programming
Lucas B.

Belo Horizonte, Brazil

$50/hr
5.0
7 jobs

I’m a software developer with deep expertise in managing the full life cycle of software development. I’ve contributed to major open-source initiatives, including Python’s core, Microsoft’s VSCode Python debugger, and Mypy. Additionally, I maintain several Python projects for Embarcadero. ⭐"𝐋𝐮𝐜𝐚𝐬 𝐢𝐬 𝐭𝐡𝐞 𝐤𝐢𝐧𝐝 𝐨𝐟 𝐜𝐨𝐧𝐭𝐫𝐚𝐜𝐭𝐨𝐫 𝐰𝐡𝐨 𝐭𝐚𝐤𝐞𝐬 𝐦𝐲 𝐯𝐚𝐠𝐮𝐞 𝐜𝐨𝐧𝐜𝐞𝐩𝐭𝐬, 𝐡𝐞𝐥𝐩𝐬 𝐦𝐞 𝐟𝐥𝐮𝐬𝐡 𝐭𝐡𝐞𝐦 𝐨𝐮𝐭, 𝐜𝐨𝐦𝐞𝐬 𝐛𝐚𝐜𝐤 𝐰𝐢𝐭𝐡 𝐟𝐮𝐥𝐥𝐲 𝐫𝐞𝐚𝐥𝐢𝐳𝐞𝐝, 𝐚𝐧𝐝 𝐩𝐥𝐞𝐚𝐬𝐚𝐧𝐭𝐥𝐲 𝐬𝐮𝐫𝐩𝐫𝐢𝐬𝐞𝐬 𝐦𝐞 𝐰𝐢𝐭𝐡 𝐭𝐡𝐞 𝐪𝐮𝐚𝐥𝐢𝐭𝐲 𝐚𝐧𝐝 𝐬𝐜𝐨𝐩𝐞 𝐨𝐟 𝐡𝐢𝐬 𝐰𝐨𝐫𝐤." - 𝐉𝐢𝐦 𝐌𝐜𝐤𝐞𝐞𝐭𝐡 (𝐂𝐡𝐢𝐞𝐟 𝐃𝐞𝐯𝐞𝐥𝐨𝐩𝐞𝐫 𝐀𝐝𝐯𝐨𝐜𝐚𝐭𝐞, 𝐄𝐦𝐛𝐚𝐫𝐜𝐚𝐝𝐞𝐫𝐨) ⭐ 🚀🚧 𝗧𝗘𝗖𝗛 𝗦𝗧𝗔𝗖𝗞 🚧🚀 Languages: Python, Delphi, JavaScript, HTML, CSS Frameworks: Django, Django-Rest Framework (DRF), Flask, FastAPI etc. Databases: PostgreSQL, MongoDB, Amazon Dynamo DB etc. Cloud Infrastructure: AWS, GCP, Azure, Heroku, DigitalOcean, Render etc Payment: Stripe, Paypal, LemonSqueezy, Razorpay etc. CI/CD: GitHub Workflows, Bitbucket Pipelines, GitLab Pipelines etc Server: Gunicorn, NGNIX, uWSGI, ASGI, Starlette etc. Testing: Unit tests, Integration tests, end-2-end (E2E) tests, Pytest Miscellaneous: Docker, Third-party APIs, OpenAI, Microservices and Monolithic architectures etc. 🚀🚧 𝗢𝗨𝗥 𝗦𝗘𝗥𝗩𝗜𝗖𝗘𝗦 🚧🚀 Web Development: Full-stack application development using Python (Django, Flask) API Services Development: Backend API services development using Django Rest Framework, FastAPI, Delphi (DMVC, Horse) Data Science / Machine Learning: Develop Vision, Speech, NLP, Recommendation Systems Open-source Development: Ready to collaborate in your open-source project initiatives. 🚀🚧 𝗖𝗔𝗟𝗟 𝗧𝗢 𝗔𝗖𝗧𝗜𝗢𝗡 🚧🚀 If you need any of the above services and if you find us interesting, please give us the chance to develop your services or applications.

  • Python
  • C++
  • Delphi
  • Microsoft Windows
  • Linux
  • Web Application
  • Mobile App Development
  • Machine Learning
  • Computer Vision
  • Large Language Model
  • Django
  • Flask
  • AWS Development
  • RabbitMQ
  • React
Hugo F.

Moreno, Argentina

$35/hr
5.0
1 jobs

I work best on software that is already a little complicated: desktop agents that need to stay running reliably, APIs connecting several systems, older code that needs to be improved without breaking production, or AI features that need to behave like part of a real product rather than a demo. Over the past 8+ years, I’ve worked across Windows, macOS, web, mobile, backend, and cloud systems, with most of my recent work focused on architecture, cross-platform development, performance, reliability, and AI integration. At iMonitorSoft, I led architecture and core module development for enterprise monitoring agents across Windows, macOS, and iOS. That involved system-level tracking of file, application, and network activity, background processing, communication and synchronization between components, platform-specific integrations, performance tuning, and AI-based event classification. Before that, I worked on full-stack web and mobile products using Python, Node.js, React, React Native, AWS, and GCP, taking projects from early product requirements through backend development, integration, deployment, and production support. CORE EXPERTISE ⚙️ C++ / .NET / CROSS-PLATFORM SYSTEMS - C++, C#, .NET, Swift, Objective-C - Windows and macOS desktop applications - Background services and long-running agents - File, application, network, and system event processing - OS-level and platform-specific integrations - Communication protocols and data synchronization - Performance, stability, and resource optimization - Debugging and modernization of existing applications 🧠 AI & AUTOMATION - LLM integration into existing software - NLP and recommendation features - AI-based classification and workflow automation - Hugging Face and TensorFlow - AI-backed APIs and application features - Connecting AI services with existing backend and product workflows 🔗 BACKEND & FULL-STACK - Python, FastAPI, Node.js, Express - React, Next.js, TypeScript, Vue.js - REST APIs and third-party integrations - PostgreSQL, MySQL, MongoDB, SQLite - SaaS backend architecture - Refactoring and extending existing codebases - Debugging issues that span multiple services ☁️ CLOUD & INFRASTRUCTURE - AWS and GCP - Docker and Kubernetes - CI/CD pipelines - Production deployment - Backend and service architecture - Troubleshooting performance and reliability issues THE KIND OF WORK I USUALLY TAKE ON - Fixing an application that has become unstable or difficult to maintain - Building or improving Windows and macOS desktop software - Developing Python, Node.js, or .NET backend services - Connecting desktop applications with APIs and cloud services - Modernizing an older codebase without rewriting everything - Integrating AI or LLM functionality into an existing product - Investigating performance, synchronization, or reliability problems - Reviewing an architecture before a product becomes harder to scale - Taking ownership of a technically complex feature from design through production I’m generally careful about recommending rewrites. If there is an existing system, I prefer to understand how it works first, reproduce the problem, and fix the underlying issue without replacing parts that are already doing their job. Sometimes that means working deep in a C++ or .NET component. Other times it means restructuring a Python API, improving communication between desktop and cloud services, adding an AI workflow, or cleaning up an architecture that has grown difficult to extend. TECHNICAL STACK Languages: C++, C#, Python, JavaScript, TypeScript, Swift, Objective-C, Go Backend: FastAPI, Node.js, Express, .NET Frontend: React, Next.js, Vue.js Databases: PostgreSQL, MySQL, MongoDB, SQLite AI: LLM Integration, NLP, TensorFlow, Hugging Face Cloud: AWS, GCP, Docker, Kubernetes, CI/CD Platforms: Windows, macOS, iOS, Android, Linux HOW I APPROACH A PROJECT - Understand the existing system before changing it - Reproduce problems instead of guessing at them - Keep architecture understandable and components well separated - Give short, clear updates while I work - Think about failure cases, not just the happy path - Leave code in a state that another engineer can comfortably continue working with If you’re building something technically demanding, dealing with an existing system that needs experienced attention, or trying to connect desktop, backend, AI, and cloud pieces cleanly, feel free to send me the details. I’m happy to look at what you have and tell you how I’d approach it.

  • Software Architecture
  • C++
  • Python
  • C#
  • .NET Framework
  • Artificial Intelligence
  • API Integration
  • FastAPI
  • Node.js
  • Desktop Application
  • Large Language Model
  • React
  • TypeScript
  • PostgreSQL
  • Amazon Web Services
  • Google Cloud Platform
  • Docker
  • Kubernetes
  • macOS
  • CI/CD
Vitalii A.

Wroclaw, Poland

$30/hr
5.0
38 jobs

I have more than 15 years of programming experience. As a freelancer, I have broad experience: I developed web (ASP.NET, Python, PHP), desktop (C++, C#, Python — Linux and Windows) and mobile (Android — Java, C++) applications. I list here some of my jobs. C#: * clubspeed.com — a large software suite for family entertainment clubs; included C# code (80%), including CoreApi and ASP.NET Razor, plus PHP (Laravel) and Node.js code (for low-level car racing control tasks). I developed it as a team member. * qadra.com — a financial company; C# code (80%), Python (some microservices are Python/Flask based, 20% of code), AWS-hosted with Docker containers and Lambdas. I developed it as a team member. * enven.nl — implemented from scratch their non-public partners portal: ASP.NET Razor and some CoreApi endpoints. * ASP.NET website for house rentals. * ASP.NET website for remote control of a robotic device via a WebSocket connection. * Vegetable-oil plant automation desktop program (C# + WinCC). Python: * Embeddable fact-checking chat that uses the LangGraph framework to implement a customizable LLM/AI backend (OpenAI, DeepSeek, Hugging Face, or Ollama). It allows administrators to embed the component in their websites so users can ask questions about facts described in articles and verify whether facts listed in an article are true. It included agentic code and many external APIs to check facts (not just asking an LLM), and even computer vision to inspect website photos (OpenCV). Backend is FastAPI. * AI/LLM-based ad selection for a website (FastAPI and LangGraph). It processes website text or chat messages and selects ads of different types related to the content. It contains SDKs for embedding ads on many platforms, including Go, React, and plain HTML. * Polish-language training software, based on Django and LangGraph. * Many small projects: desktop scripts, web scraping (Selenium and related tools), and simple AI agents. C++: * Factory equipment monitoring system (Ubuntu Linux, custom server over TCP/IP, web interface in PHP). * Many small projects, some of which are mentioned in reviews on this profile; many are non-public. * Powerful software for automated ad submission on social networks (massive bots that send millions of messages). PHP: * 20+ websites — without CMS, with my own CMS, and with open-source Drupal, WordPress and Joomla CMSs. * Backends for Android applications. Android: * SOCKS5 proxy application that allows sharing mobile VPN with non-mobile clients via the SOCKS protocol. * Many WebView-based "business card" applications. * Dating-related applications, including erotic puzzles. Human emulation: * Spam bots — I cannot provide a specific list of such software for legal reasons. * Automatic checkout on eBay and similar websites. * PayPal automatic payments. * Data scraping, including air tickets and goods in online stores. Reverse engineering — I cannot provide a specific list of reverse-engineered software for legal reasons. * Java bytecode reverse engineering, including Android. * .NET bytecode reverse engineering. * Machine code for 32-bit and 64-bit x86 and ARM CPUs. Assembler: * High-performance cryptographic library for x86\_64 CPUs.

  • .NET Framework
  • MySQL Programming
  • JavaScript
  • PHP
  • Python
  • ASP.NET
  • VB.NET
  • Node.js
  • HTML
  • C#
  • Java
  • C++
  • .NET Core
  • ASP.NET Core
  • .NET Stack
  • Microsoft Windows
  • Android
  • Linux
Iman O.

Cyberjaya, Malaysia

$30/hr
5.0
11 jobs

I build practical automation tools that connect APIs, Excel/CSV files, Raspberry Pi/Linux systems, printers, hardware devices, and business workflows. I have 10+ years of software engineering experience in Python, C++, PHP/CakePHP, MySQL, Linux, embedded systems, hardware/software integration, and backend automation. I also hold a PhD in image processing. My strongest work is solving real-world integration problems: API data extraction, Excel automation, thermal printer workflows, Raspberry Pi services, serial/I2C/SPI communication, device monitoring, web scraping, backend systems, and technical debugging. I can help you build reliable tools, fix unstable systems, automate manual workflows, connect devices/software, and deliver maintainable solutions that work in production.

  • Python
  • API Integration
  • Automation
  • Raspberry Pi
  • Embedded Linux
  • C++
  • C#
  • .NET Framework
  • PHP
  • Web Scraping
  • MySQL
  • Arduino
  • Visual Basic
  • HTML
  • JavaScript
  • SQL
  • Google Chrome Extension
  • Firefox Plugin Development
  • Linux
  • Image Processing
Otabek X.

Kosonsoy, Uzbekistan

$50/hr
5.0
27 jobs

𝐋𝐞𝐭'𝐬 𝐜𝐫𝐚𝐜𝐤: 𝐆𝐨𝐨𝐠𝐥𝐞, 𝐌𝐞𝐭𝐚, 𝐀𝐦𝐚𝐳𝐨𝐧, 𝐌𝐢𝐜𝐫𝐨𝐬𝐨𝐟𝐭, 𝐞𝐭𝐜 - 𝐂𝐨𝐝𝐢𝐧𝐠 𝐈𝐧𝐭𝐞𝐫𝐯𝐢𝐞𝐰𝐬 🚀🚀🚀 🧠 𝗪𝗵𝗮𝘁 𝗜 𝗢𝗳𝗳𝗲𝗿: — 1-on-1 mentoring for FAANG interviews — Deep dive into LeetCode patterns — Custom roadmap for your level ⭐️ 𝗥𝗲𝗮𝗱 𝗪𝗵𝗮𝘁 𝗠𝘆 𝗦𝘁𝘂𝗱𝗲𝗻𝘁𝘀 𝗧𝗲𝗹𝗹 𝗔𝗯𝗼𝘂𝘁 𝗠𝗲: "𝘐 𝘩𝘪𝘨𝘩𝘭𝘺 𝘳𝘦𝘤𝘰𝘮𝘮𝘦𝘯𝘥 𝘮𝘺 𝘮𝘦𝘯𝘵𝘰𝘳 𝘧𝘰𝘳 𝘩𝘪𝘴 𝘦𝘹𝘤𝘦𝘱𝘵𝘪𝘰𝘯𝘢𝘭 𝘢𝘣𝘪𝘭𝘪𝘵𝘺 𝘵𝘰 𝘵𝘦𝘢𝘤𝘩 𝘓𝘦𝘦𝘵𝘊𝘰𝘥𝘦 𝘢𝘭𝘨𝘰𝘳𝘪𝘵𝘩𝘮𝘴. 𝘏𝘪𝘴 𝘦𝘹𝘱𝘦𝘳𝘵𝘪𝘴𝘦 𝘢𝘯𝘥 𝘱𝘢𝘵𝘪𝘦𝘯𝘵 𝘨𝘶𝘪𝘥𝘢𝘯𝘤𝘦 𝘮𝘢𝘥𝘦 𝘤𝘰𝘮𝘱𝘭𝘦𝘹 𝘤𝘰𝘯𝘤𝘦𝘱𝘵𝘴 𝘦𝘢𝘴𝘺 𝘵𝘰 𝘨𝘳𝘢𝘴𝘱." — 𝘕𝘢𝘩𝘪𝘥 𝘔𝘶𝘴𝘵𝘢𝘧𝘢 (𝘚𝘦𝘯𝘪𝘰𝘳 𝘚𝘰𝘧𝘵𝘸𝘢𝘳𝘦 𝘌𝘯𝘨𝘪𝘯𝘦𝘦𝘳 @ 𝘈𝘴𝘤𝘦𝘯𝘥 𝘛𝘦𝘤𝘩𝘯𝘰𝘭𝘰𝘨𝘺 - 𝘊𝘢𝘭𝘪𝘧𝘰𝘳𝘯𝘪𝘢, 𝘜𝘚𝘈) 🚀 𝗠𝘆 𝗔𝗰𝗵𝗶𝗲𝘃𝗲𝗺𝗲𝗻𝘁𝘀: — Top 1% in LeetCode — 2150+ contest ranking — 1000+ problems solved — 650K views for solutions 𝗜 𝗠𝗲𝗻𝘁𝗼𝗿: LeetCode, Algorithms, Data Structures, Hackerrank, Python, Java, C++, JavaScript, C#, Go, etc. 𝗥𝗲𝗮𝗱𝘆 𝘁𝗼 𝗮𝗰𝗲 𝘆𝗼𝘂𝗿 𝘁𝗲𝗰𝗵 𝗶𝗻𝘁𝗲𝗿𝘃𝗶𝗲𝘄? 𝗟𝗲𝘁’𝘀 𝗰𝗼𝗻𝗻𝗲𝗰𝘁! 💬

  • Algorithms
  • Data Structures
  • Interview Preparation
  • Mock Interview
  • C#
  • Python
  • Java
  • Coding Lesson
  • Tutoring
  • C++
  • Golang
  • JavaScript
  • HackerRank
  • Artificial Intelligence
  • C

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What Is Object-Oriented Programming and Why Is It Important?

You’ve probably seen most back-end programming languages described as object-oriented programming (OOP)—so what is object-orientation in web development, and why is it important?

At its core, it’s a logic—one we use in daily life. We naturally think of things as objects with attributes and behaviors, and that determines how we interact with them. It’s interacting in the abstract, and it’s why OOP can boost speed and efficiency.

What is abstract interaction?

If you want to change the television channel from your seat, you use a remote control. That remote control is an object with a number of attributes and behaviors hidden inside of it. Without an understanding of those hidden attributes—the microchips, wiring, etc.—you still know and expect that pressing a button will perform that particular function. You’ve interacted with the remote control in the abstract, skipping the steps the remote was designed to carry out. That’s the beauty of OOP—the focus is on how the objects behave, not the code required to tell them how to behave.

So, what are objects?

A car is an example of a complex object, with many attributes. We don’t need to understand all of its internal mechanics, what kind of engine it has, how the gas makes it run, or even where the gas came from in order to know how to interact with it. The car’s behaviors have been made simple for us through object-oriented logic: put the key in the ignition, and the car turns on and gets us where we need to go. The attributes that make this possible—all of the car’s parts, electronics, and engineering—are a “package” we don’t need to break down in order to understand.

Apply this to software building, and it allows developers to break down big, complicated projects into compartmentalized objects, program them to have attributes and behaviors, then essentially set them aside and focus on programming how the objects interact—a higher level of thinking that makes writing code less linear and more efficient. Modern, high-level languages like Python and Ruby are perfect examples of OOP. The fact that they’re able to be so streamlined gets right to the heart of OOP logic.

Object-oriented programming & back-end development

What is object-oriented programming in terms of how a site is built? OOP defines most modern server-side scripting languages, which are the languages back-end developers use to write software and database technology. This behind-the-scenes, server-side technology tells a website or web application how to behave, and also builds the architecture for a site to interact with its database. That scaffolding is how data is delivered and processed, effectively making it the brain of a website. And that’s where object-oriented logic comes into play.

If a website’s brain uses object-oriented logic, it’s designed to think of data as objects. It affects how a site is built from the ground up, how data is organized, how later growth and maintenance of the site will occur, and more.

Benefits of object-oriented technology include:

  • Ease of software design
  • Productivity
  • Easy testing, debugging, and maintenance
  • It’s reusable
  • More thorough data analysis, less development time, and more accurate coding, thanks to OOP’s inheritance method
  • Data is safe and secure, with less data corruption, thanks to hiding and abstraction
  • It’s sharable (classes are reusable and can be distributed to other networks)

The building blocks of object-oriented programming

Objects are central to OOP, but they’re not the only moving part. Here’s a closer look at the other building blocks, and how they work in tandem to create back-end code that houses, moves, and manipulates data from a database into a usable web application.

  1. Objects: An object is the core unit of OOP. Objects are uniquely named and represent an instance of a class. Each object houses different states (attributes), and shared behaviors, called methods. For example, a Prius is an object in the class of “cars,” in a subclass of “hybrid cars.” Its attributes include anything from the number of doors it has to how its electric component is charged. It’s similar to other cars by its behavior—it drives—but its attributes are what set it apart.
  2. Classes: A class is a blueprint for how an object is built, as well as being a sort of “parent category” for objects. Using the previous example, a class dictates the concept of a car—four wheels, an engine, a body, brakes, etc. It allows certain set criteria to be passed down to all objects in the class. All varieties of cars behave relatively the same on a basic level, but its their attributes and methods that make them unique.
  3. Inheritance: This is an important aspect of OOP, hinted at above. By deriving classes from parent classes, behaviors can be passed down to objects, then more complicated attributes can be added the deeper you go. For example, breaking a car into subclasses (car → sports car → V8 sports car) makes it possible to layer in more features without starting from scratch.
  4. Abstraction & Encapsulation: This describes how attributes are housed and hidden within an object—including its data. Objects are designed to only reveal the necessary data, allowing software to interact with the object on a higher level. It’s equal parts security and simplicity. In the case of car parts, by safely stowing them within the body of an assembled car, things are less likely to get broken, and users can interact with the big picture: pressing the gas means go, no questions asked.

Procedural languages vs. object-oriented languages

Procedural programming (via languages like ColdFusion) is code that is broken into “procedures”—it’s a different way of thinking about how code interacts with data that’s more linear. Procedures are functional bits of code that interact with and change data, like little machines that gather input, process it, then deliver output. With OOP, however, data and functions (attributes and methods) are bundled together within the object. This prevents the need for any shared or global data with OOP, which is a core difference between the two approaches.

Traditional procedural languages like C and Pascal require you to think in terms of the computer rather than thinking in terms of the problem you’re trying to solve. For less complicated applications, procedural languages offer ease and transparency that bundled objects don’t always allow—something that can make it more difficult for programmers to analyze smaller bits of code on the tail-end of the development process.

When it comes to creating reusable components in software, OOP is the clear winner. Reusability leads to efficiency, simplifying programming and creating “shortcuts” to software design.

Popular object-oriented languages

  • Simula, the first object-oriented programming language
  • Java
  • Python
  • Ruby
  • C++
  • Smalltalk
  • Visual Basic .NET
  • Objective-C: OOP is a core tenet of iOS mobile app programming, and Objective-C is essentially the C language with an object-oriented layer.
  • Curl
  • Delphi
  • Eiffel