Alexandros Elegreris, Developer in Athens, Central Athens, Greece
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Alexandros Elegreris

Verified Expert  in Engineering

WebSockets Developer

Location
Athens, Central Athens, Greece
Toptal Member Since
March 4, 2024

Alexander is an engineer who excels in various environments, from the fast-paced tech hubs of New York to the demanding ecosystems of Zurich. He has led transformative projects that have significantly improved system performance and operational efficiency. With experience leading teams in the Agile methodology, Alexandros' approach combines technical mastery with visionary leadership, driving his teams toward groundbreaking achievements.

Portfolio

Stork
Amazon Web Services (AWS), API Architecture, Amazon DynamoDB, FastAPI, Redis...
21.co
Amazon Web Services (AWS), API Architecture, Microservices, Docker, Kubernetes...
Embed
API Architecture, Python, FastAPI, Flask, GraphQL, Node.js, TypeScript...

Experience

Availability

Part-time

Preferred Environment

Linux, Windows, Slack

The most amazing...

...thing I've worked on is a system for managing manual and automatic trades, enhancing the reliability of trading operations for the largest crypto ETF.

Work Experience

Principal Engineer

2022 - 2024
Stork
  • Led a team of five engineers in the evaluation and re-architecture of the entire infrastructure, significantly increasing system speed and efficiency while reducing operational costs.
  • Worked on the monolithic design on AWS, using Rust for efficient high-speed signing; Python, FastAPI, and Redis for rapid result processing; and Docker for containerization, establishing Stork as a premier ultra-low latency reference price provider.
  • Created a tailored weighted mark price oracle for Vertex.
  • Led the engineering team focusing on Agile methodology practices. Successfully implemented strategies that improved project agility and team dynamics.
  • Piloted large-scale projects, including Web3 and blockchain initiatives, propelling company growth and market success.
  • Created a tailored spot oracle for OKX and an integration infrastructure for their custom API.
Technologies: Amazon Web Services (AWS), API Architecture, Amazon DynamoDB, FastAPI, Redis, Rust, Low Latency, RabbitMQ, Algorithms, High-load, Relational Databases, Python, Docker, Kubernetes, GitHub, CI/CD Pipelines, WebSockets, Code Review, Back-end, APIs, Asynchronous Programming, Unit Testing, Code Refactoring, Database Modeling, SQL, Apache Kafka, Back-end Development, Containerization, Database Design, Database Optimization, Leadership, Performance Optimization, RESTful Services, Scalability, Technical Leadership, DevOps, Architecture, MongoDB, API Integration, Finance, Finance APIs, Trading Systems, Agile, REST APIs, Back-end Architecture, Management, Delivery Management, Engineering Management, Software Architecture, Web Development, Web Applications, Web Dashboards, JSON, Pytest, Abstract Syntax Trees (AST), Databricks, AI Integration, Data Science, Data Architecture, Cloud Native, Cloud Deployment, AWS Lambda, Message Queues, Serverless, API Design, API/Services Architecture, Integration, API Gateways, Microservices Architecture, Auth0, SQLAlchemy, Data Pipelines, Blockchain, Cryptocurrency, Python Asyncio, Socket.IO, Scalable Web Services, Databases, Bloomberg API, Matplotlib, Pandas, Financial Data, Statistics, Project Planning, Requirements Analysis, Project Timelines, Amazon S3 (AWS S3), OpenAI, ChatGPT

Senior Software and Trading Engineer

2022 - 2023
21.co
  • Co-led a team of over eight engineers, co-designed and co-built a full-stack, microservices-based order management system (OMS) using Python, FastAPI, RabbitMQ, and Redis, containerized with Docker, orchestrated with Kubernetes, and deployed on AWS.
  • Worked on a system vital for managing manual and automatic trades, enhancing the scalability and reliability of trading operations for the world's largest crypto ETF.
  • Developed a high-frequency trading (HFT) low latency system with a monolithic design using Rust and C++, significantly enhancing the trading capabilities and performance of the world's largest crypto exchange-traded funds (ETF).
  • Led the design and implementation of an identity access management (IAM) system for the OMS, ensuring secure and efficient trader operations in a blockchain-centric environment.
  • Partnered with world-class traders from Bank of America, Deutsche Bank, and UniCredit to translate complex trading strategies into effective, reliable algorithms.
  • Managed comprehensive testing and maintenance protocols for trading systems, focusing on speed optimization, bug resolution, and edge case identification to guarantee robustness in live trading environments.
Technologies: Amazon Web Services (AWS), API Architecture, Microservices, Docker, Kubernetes, Amazon EKS, Python, FastAPI, RabbitMQ, Redis, Go, Rust, Low Latency, Trading, Algorithms, NoSQL, C++, Next.js, TypeScript, GitHub, CI/CD Pipelines, Code Review, Algorithmic Trading, Interviewing, WebSockets, High-load, Back-end, APIs, Asynchronous Programming, Unit Testing, Code Refactoring, JavaScript, Database Modeling, UI Design, SQL, Apache Kafka, Back-end Development, Containerization, Database Design, Database Optimization, Leadership, Performance Optimization, RESTful Services, Scalability, Technical Leadership, DevOps, Full-stack, Software Design, Architecture, MongoDB, API Integration, Finance, Finance APIs, Trading Systems, React, Agile, Full-stack Development, REST APIs, Back-end Architecture, Websites, CSS, HTML, Node.js, Management, Delivery Management, Engineering Management, Software Architecture, Automation, UI Automation, Workflow Automation, Selenium, Web Development, Puppeteer, Generative Pre-trained Transformers (GPT), Web Applications, OpenAI GPT-4 API, Web Dashboards, Web Scraping, Data Scraping, Website Data Scraping, JSON, Pytest, Abstract Syntax Trees (AST), Databricks, Data Science, User Experience (UX), User Interface (UI), Data Architecture, Front-end Development, Cloud Native, Artificial Intelligence (AI), Cloud Deployment, AWS Lambda, Message Queues, Serverless, Amazon Simple Queue Service (SQS), API Design, API/Services Architecture, Integration, API Gateways, Microservices Architecture, Angular, Okta, SQLAlchemy, Graphical User Interface (GUI), Data Pipelines, Blockchain, Cryptocurrency, Python Asyncio, Socket.IO, Databases, Bloomberg API, Matplotlib, Pandas, Financial Data, Statistics, Project Planning, Requirements Analysis, Project Timelines, Amazon S3 (AWS S3), AI Website Builders, Web Crawlers, OpenAI, ChatGPT

Senior Software Engineer

2022 - 2022
Embed
  • Redesigned the architecture and infrastructure, helping the team deal with the increased volume of traffic that their previous architecture could not handle.
  • Worked on the redesign that saved operating costs and the new architecture that simplified the complicated schema and helped speed up maintenance and new feature development.
  • Assisted the business in shaping many of their ideas into effective products.
  • Consulted on various security matters and erased previous technical debt.
Technologies: API Architecture, Python, FastAPI, Flask, GraphQL, Node.js, TypeScript, Microservices, Back-end, APIs, Code Refactoring, Database Modeling, UI Design, SQL, Back-end Development, Containerization, Database Design, Database Optimization, Performance Optimization, RESTful Services, Scalability, Full-stack, Architecture, MongoDB, Agile, REST APIs, Back-end Architecture, Google Cloud, Software Architecture, Web Development, Web Applications, JSON, Data Architecture, Vue, Front-end Development, Cloud Native, Cloud Deployment, Tailwind CSS, Message Queues, API Design, API/Services Architecture, Email Automation, Microservices Architecture, Auth0, SQLAlchemy, Data Pipelines, Blockchain, Cryptocurrency, Python Asyncio, Socket.IO, Databases, Pandas, Project Planning, Requirements Analysis, Project Timelines

Principal Engineer

2018 - 2022
ClearViewAI
  • Developed pipelines, databases, and APIs, primarily built in Python, certifying that they were robust, efficient, and fast enough to handle data on the scale of hundreds of terabytes. Used Redis, MongoDB, RabbitMQ, PostgreSQL, and Spark.
  • Developed advanced web crawlers by leveraging Python, JavaScript, and Node.js in combination with Selenium, BeautifulSoup, and a custom Chromium-based browser. Custom anti-evasion techniques and traffic analysis further refined the process.
  • Developed software verification plans and quality assurance procedures and troubleshot, debugged, and upgraded existing systems.
  • Led a team of more than 12 engineers focusing on Agile methodology practices and successfully implemented strategies that improved project agility and team dynamics.
Technologies: Amazon Web Services (AWS), ETL, NoSQL, Redis, PostgreSQL, Python, Selenium, Java, API Architecture, C++, Flask, JavaScript, Docker, Kubernetes, GitLab, Machine Learning, Code Review, Interviewing, React, Bots, Scraping, Back-end, APIs, Asynchronous Programming, Unit Testing, Code Refactoring, Database Modeling, UI Design, SQL, RabbitMQ, Back-end Development, Containerization, Database Design, Database Optimization, Leadership, Performance Optimization, RESTful Services, Scalability, Technical Leadership, DevOps, Full-stack, Software Design, Architecture, MongoDB, Agile, Full-stack Development, REST APIs, WebRTC, Back-end Architecture, Websites, CSS, HTML, React Native, Management, Delivery Management, Engineering Management, Software Architecture, Automation, UI Automation, Workflow Automation, Web Development, Algorithms, Beautiful Soup, Puppeteer, Web Applications, Web Dashboards, Web Scraping, Data Scraping, F5 Networks, Website Data Scraping, JSON, Pytest, AI Integration, Data Science, User Experience (UX), User Interface (UI), Data Architecture, Front-end Development, Cloud Native, Artificial Intelligence (AI), Cloud Deployment, Message Queues, API Design, API/Services Architecture, Microservices Architecture, MySQL, SQLAlchemy, Graphical User Interface (GUI), Data Pipelines, Python Asyncio, Celery, Scalable Web Services, Databases, Pandas, Project Planning, Requirements Analysis, Project Timelines, Amazon S3 (AWS S3), Web Crawlers, Scrapy

Senior Software Engineer

2014 - 2017
Artiusio
  • Developed and worked on enterprise software for medium and large-size corporations.
  • Configured and deployed enterprise software for various hotels and businesses. Created a customer relationship management (CRM) and a booking solution consisting of a desktop and a web application.
  • Monitored and updated client websites while playing a key role in expanding the company's and client's operations.
Technologies: Django, Python, Amazon Web Services (AWS), Web Development, PostgreSQL, WordPress, Back-end, APIs, Code Refactoring, UI Design, SQL, Back-end Development, Containerization, RESTful Services, Full-stack, Software Design, Full-stack Development, REST APIs, Back-end Architecture, Websites, CSS, HTML, Software Architecture, Web Applications, JSON, User Experience (UX), User Interface (UI), Front-end Development, Cloud Native, Message Queues, API Design, API/Services Architecture, MySQL, Booking, SQLAlchemy, Graphical User Interface (GUI), Content Management Systems (CMS), Databases, Pandas, R, Requirements Analysis, Project Timelines, Mailchimp

Facial Recognition

http://clearview.ai
I joined as one of the inaugural engineers at a budding startup before it even formalized its corporate entity. I dedicated countless hours to its development, and my commitment paid off as we ascended to become a leader in our industry, earning accolades, including mentions in The New York Times and being listed among the TIME100 Most Influential Companies of 2021.

Trading System

I was initially hired to develop an order management system (OMS) for manual trading. I spearheaded the project's expansion to create a comprehensive OMS that supports algorithmic and high-frequency trading and delivers real-time data. This endeavor was enriched through collaboration with world-class quants from leading financial institutions, including Bank of America, Deutsche Bank, and UniCredit, significantly enhancing the system's functionality and impact.

Stork

I optimized an overly complex and costly price oracle provider by reducing operational costs by more than half and streamlining its design with essential tools. This significantly boosted its speed, enabling the project to withstand the challenges of the crypto winter.

Libraries/APIs

React, Node.js, REST APIs, Beautiful Soup, Puppeteer, SQLAlchemy, Python Asyncio, Socket.IO, ZeroMQ, Vue, Bloomberg API, Matplotlib, Pandas, WebRTC

Tools

Pytest, ChatGPT, RabbitMQ, Amazon EKS, GitHub, GitLab, Amazon Simple Queue Service (SQS), Auth0, Celery, Mailchimp, Slack

Frameworks

Django, Selenium, Scrapy, Flask, Next.js, gRPC, React Native, Tailwind CSS, Angular

Languages

Python, JavaScript, CSS, HTML, SQL, C++, TypeScript, Go, Java, GraphQL, Rust, R

Paradigms

Asynchronous Programming, Unit Testing, Database Design, Agile, Back-end Architecture, Management, Automation, API/Services Architecture, Microservices Architecture, Requirements Analysis, Microservices, API Architecture, ETL, Code Refactoring, UI Design, DevOps, Data Science, Low-code Development

Platforms

Amazon Web Services (AWS), Cloud Native, AWS Lambda, Blockchain, Linux, Windows, Kubernetes, Docker, WordPress, Apache Kafka, Databricks

Storage

JSON, Cloud Deployment, MySQL, Data Pipelines, Databases, Amazon S3 (AWS S3), PostgreSQL, MongoDB, Amazon DynamoDB, Redis, Relational Databases, NoSQL, Database Modeling, Google Cloud

Industry Expertise

Trading Systems

Other

FastAPI, WebSockets, Web Development, Bots, Full-stack, Scraping, Back-end, APIs, Back-end Development, Containerization, Leadership, Performance Optimization, RESTful Services, Scalability, Technical Leadership, Architecture, API Integration, Full-stack Development, Delivery Management, Engineering Management, UI Automation, Workflow Automation, Web Applications, Web Scraping, Data Scraping, F5 Networks, Website Data Scraping, Data Architecture, Message Queues, Serverless, API Design, Integration, API Gateways, Cryptocurrency, Scalable Web Services, Project Planning, Project Timelines, Web Crawlers, Low Latency, Trading, Algorithms, High-load, CI/CD Pipelines, Code Review, Algorithmic Trading, Interviewing, Database Optimization, Software Design, Finance, Finance APIs, Websites, Software Architecture, Generative Pre-trained Transformers (GPT), OpenAI GPT-4 API, Web Dashboards, Abstract Syntax Trees (AST), AI Integration, User Interface (UI), Front-end Development, Artificial Intelligence (AI), Okta, Booking, Graphical User Interface (GUI), Content Management Systems (CMS), Financial Data, OpenAI, Machine Learning, Low-latency Software, User Experience (UX), Email Automation, Statistics, AI Website Builders

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