Ghassan is available for hire

Ghassan Hallaq

Verified Expert in Engineering

Solution Architect and Software Developer

Location

Montreal, QC, Canada

Toptal Member Since

June 13, 2019

Gus is passionate and curious about the latest tech trends and makes sure to be up-to-date with all useful tools, such as Java, Scala, JavaScript, TypeScript, Python, and Rust, to name a few. Gus aims to bring new solutions to today’s challenges in the realms of data warehouses and pipelines, eCommerce, eBPF, cryptocurrency, NFT, dApp, and Blockchain.

Data Warehouse Design Data Warehousing Data Vaults Service-oriented Architecture (SOA)Data Analytics Scala Apache Spark Serverless REST APIs TypeScript Elasticsearch Node.js Java 8 ETL Python 3

Portfolio

Pillar Base, Inc.

BigCommerce API, TypeScript, Spark SQL, Amazon Cognito, Amazon DynamoDB...

UBS - Main

Java, Spring 5, Spring Boot, Puppet, Ansible, Rust, Go, GitLab CI/CD, C++, C...

Endeavor - Main

SQL, Java, Snowflake, Hadoop, Pandas, Python 3, Data Build Tool (dbt)...

Experience

Solution Architecture - 8 years Go - 6 years Node.js - 5 years Python 3 - 5 years Data Warehousing - 5 years Elixir - 5 years Phoenix - 4 years Rust - 3 years

Availability

Part-time

Preferred Environment

Linux, Amazon Web Services (AWS), Azure, Elixir, Python 3, Go, Rust

The most amazing...

...integration solution I've built is based on techs like TypeScript/AWS Serverless/OAuth 2 to integrate with BigCommerce, Google Shopping, and Facebook Commerce.

Work Experience

Senior Data and Solution Architect

2019 - PRESENT

Pillar Base, Inc.

Developed an application to denormalize data from the relational database and stream it to an AWS DynamoDB single table.
Worked on a proof of concept (POC) to assess the performance between Spark SQL, Presto DB, and Apache Drill with parquet files.
Architected and developed integration solutions based on AWS Lambda, API Gateways, Cognito, WMS, Facebook Open Graph API, Google Ads API, BigCommerce, AWS DynamoDB, JavaScript, and TypeScript.
Built a highly concurrent and fault-tolerant back-end engine that handles over one million requests using Rust. Worked on the POC to compare Rust concurrency with Go concurrency.
Minted NFTs, integrated them with a website, and built a dApp.
Built many ETL pipelines to ingest from/to Snowflake and created a data-based app using Streamlit and Snowpark. Created ETL between Snowflake and BigQuery.
Created a real-time notification engine based on Elixir, Phoenix, and Erlang programming models.

Technologies: BigCommerce API, TypeScript, Spark SQL, Amazon Cognito, Amazon DynamoDB, AWS Lambda, Serverless, Rust, DApps, Ethereum, Solidity, Web3.js, Solution Architecture, Go, Qiskit Runtime, Full-stack, Software Architecture, Architecture, Next.js, MongoDB, Artificial Intelligence (AI), APIs, Shopify, Team Leadership, OpenAI GPT-3 API, OpenAI GPT-4 API, Remote Team Leadership, Snowflake, Data Architecture, Phoenix, Google BigQuery, Elixir, Erlang (OTP), Java 8, NoSQL, PostgreSQL, Big Data, ETL Development, Data Engineering, MySQL/MariaDB, Functional Programming, Git, GraphQL

Lead Nexus Engineer

2022 - 2023

UBS - Main

Analyzed and enhanced the back-end performance using multiple methods to optimize the database indexing.
Helped the team start migrating the back end from Oracle to a PostgreSQL database.
Built an integration between the Java back end and security keys repo.

Technologies: Java, Spring 5, Spring Boot, Puppet, Ansible, Rust, Go, GitLab CI/CD, C++, C, REST APIs, Java 8, NoSQL, PostgreSQL, Data Engineering, MySQL/MariaDB, Functional Programming, Git

Expert Data Engineer (Python and SQL)

2021 - 2023

Endeavor - Main

Architected a CDP data warehouse on Snowflake using the Data Vault v2 methodology.
Built ETLs to manage the data flow from/to the data warehouse using Prefect 2.0.
Implemented data governance and privacy to protect the PII data.
Created dashboards using the Streamlit library in Snowflake.
Built and deployed ML data models using the Snowpark library.

Technologies: SQL, Java, Snowflake, Hadoop, Pandas, Python 3, Data Build Tool (dbt), GitHub API, ETL, Elixir, Phoenix, Agile Software Development, Data Warehouse Design, Data Analytics, REST APIs, NoSQL, Big Data Architect, PostgreSQL, Big Data, ETL Development, Data Engineering, MySQL/MariaDB, Functional Programming, Git, GraphQL

Go Developer

2022 - 2022

INSTRUXI LIMITED

Developed an integration layer between Go and the Ethereum contract.
Integrated with Redis service for caching and speed optimization.
Developed a Helm chart to enhance the deployment of Casbin-Mesh.

Technologies: Go, Kubernetes, Python, Redis, JSON Web Tokens (JWT), Helm, Web3.js, Blockchain, Casbin-Mesh, Full-stack, REST APIs, PostgreSQL, MySQL/MariaDB, Functional Programming, Serverless Architecture, Git, GraphQL

Rust Smart Contract Developer

2022 - 2022

PHI VENTURES Limited

Added features to the Rust smart contract and some tests for them.
Rearchitected the front-end React application to use the back end to access the contract features.
Built the back end and a deployment pipeline using GitHub actions.

Technologies: Rust, JavaScript, TypeScript, Solana, Node.js, Express.js, Web3.js, REST APIs, NoSQL, PostgreSQL, MySQL/MariaDB, Functional Programming, Serverless Architecture, Git

Elasticsearch Expert

2021 - 2021

Valence

Integrated Django with Elasticsearch. Built highly customizable indexes.
Monitored and helped the team to deploy that solution.
Analyzed the search result, adjusting the indexing parameters to update the priorities.

Technologies: Elasticsearch, Python 3, Django, Full-stack, Flask, Data Warehouse Design, REST APIs, NoSQL, PostgreSQL, Data Engineering, MySQL/MariaDB, Functional Programming, Apache Solr, Serverless Architecture, Git, GraphQL

Senior eCommerce Integration Engineer

2020 - 2021

Deliverr

Worked on a serverless project to develop a REST API to integrate with a different store management API.
Developed REST services to integrate with BigCommerce, Google Shopping, and Facebook Shop.
Used OAuth 2.0 and OIDC protocols to protect the API and manage the authentication and authorization with another eCommerce API.

Technologies: Serverless, AWS Lambda, Facebook API, BigCommerce API, TypeScript, Node.js, Full-stack, Data Warehouse Design, REST APIs, PostgreSQL, MySQL/MariaDB, Functional Programming, Serverless Architecture, Git, GraphQL

Senior Software Developer

2019 - 2020

ReactiveCore

Architected and developed a solution to implement a worker thread pattern integrated with Apache Kafka.
Rearchitected the microservices components to implement the service mesh (Istio) in Kubernetes over the Amazon EKS cluster.
Built a real-time streaming solution on AWS using Kinesis and Glue. Developed a data model.
Implemented Apache Spark streaming with Apache Kafka to support the data model.
Integrated Apache Druid with Apache Kafka to implement time-series analytics on the Amazon EKS cluster.
Worked on a POC and built a solution to ingest from Kafka based on Rust concurrency.
Used Elixir, Phoenix, and Erlang to build a document parser integrated with a triplestore database tocreated a knowledge graph.

Technologies: Amazon Kinesis, React, Node.js, Kubernetes, Spark, Apache Kafka, AWS Glue, Amazon EKS, Go, Akka, Scala, Rust, Full-stack, Service-oriented Architecture (SOA), Elixir, Erlang (OTP), Phoenix, REST APIs, Java 8, NoSQL, PySpark, PostgreSQL, Big Data, ETL Development, Data Engineering, MySQL/MariaDB, Service Meshes, ETL Implementation & Design, Functional Programming, Graph Databases, Git

Senior Data Engineer

2019 - 2019

BCG GAMMA

Developed and optimized the Apache Airflow graph solution to support the data model.
Packaged the solution using Docker and Docker Compose.
Built a workflow in CircleCI to automate the building, packaging, and deploying processes.
Developed a big data ETL solution on Azure Cloud based on DataFactory and integrated with Data Lake Analytics.

Technologies: Docker Compose, Docker, Apache Airflow, Python, Data Warehouse Design, Data Analytics, REST APIs, PostgreSQL, Big Data, Oracle, ETL Development, Data Engineering, MySQL/MariaDB, ETL Implementation & Design, Functional Programming, Git

Senior Solution Architect

2019 - 2019

CN Railway

Built real-time and batch processing ETL solutions based on the DataFactory.
Architected and developed an event-driven application using Node.js, React, and GraphQL using Serverless tech.
Built and architected an integration solution using Apache Kafka on the AWS EKS cluster with Azure Power BI.
Designed a solution based on React and Node.js and deployed the solution using Docker and Kubernetes.
Developed and architected a solution to stream the data into the data warehouse on Azure.
Engineered interactive dashboards using Power BI with a data warehouse.

Technologies: Kubernetes, Node.js, React, Apache Spark, Apache Kafka, Amazon Elastic MapReduce (EMR), Python, Scala, Java, Solution Architecture, Data Warehousing, Full-stack, Data Vaults, Data Analytics, REST APIs, Java 8, PostgreSQL, Big Data, Oracle, ETL Development, MySQL/MariaDB, ETL Implementation & Design, Functional Programming, Git

Big Data Architect

2016 - 2019

Morgan Stanley

Architected and developed a big data ETL solution based on AWS EMR and AWS Kinesis.
Built a knowledge graph using a triple store database and Elasticsearch.
Created a data streaming solution using S3, Lambda functions, AWS Kinesis data streaming, and AWS EMR service.
Helped develop an NLP solution to enhance and enrich features in the market data reports as a data analyst.
Built an interactive data UI based on React and React D3 integrated with Azure Power BI.
Developed a search engine for market data integrated with Elasticsearch and Apache Solr.
Worked on a POC to compare the latency between C++ and Go.
Built a highly concurrent and fault-tolerant back-end engine that handles over one million requests using Rust.
Worked on Nexus lifecycle and repos to securely manage the open source libraries.
Built a document parser—using Elixir, Phoenix, and Erlang—integrated with a triplestore database to create a knowledge graph.

Technologies: Deep Learning, Amazon Elastic MapReduce (EMR), Machine Learning, Generative Pre-trained Transformers (GPT), GPT, Natural Language Processing (NLP), React, Amazon Kinesis, Node.js, Python, Go, Java, Scala, Rust, Networks, Elixir, Erlang (OTP), Phoenix, Data Analytics, REST APIs, PySpark, Big Data Architect, PostgreSQL, Big Data, Oracle, ETL Development, Data Engineering, MySQL/MariaDB, ETL Implementation & Design, Functional Programming, Apache Solr, Graph Databases, Git

Big Data Developer

2016 - 2016

TD Bank

Developed a solution to three ETL big data projects using Apache Hive and Oozie.
Worked as part of the team on extending Hadoop security functionality.
Architected and developed a multi-threaded Java application to integrate a Linux local account with the Active directory, business requirement analysis, and sketching technical solution.
Received “Act for Impact Award” for my work on a security project.

Technologies: Spark, Hadoop, Go, Scala, Java, REST APIs, Java 8, PySpark, Big Data Architect, PostgreSQL, Big Data, Oracle, ETL Development, Data Engineering, MySQL/MariaDB, ETL Implementation & Design, Functional Programming, Graph Databases, Git

Experience

Act for Impact Award

I had the privilege of being recognized for my outstanding work on a security project, where I dedicated myself to enhancing the level of protection on each machine. Additionally, I diligently closed numerous unused ports on a daily basis.

Market Adviser Chatbot

A Python-based project to build a chatbot that will answer the client's questions regarding the security market. According to some ontologies, the project ingests market reports into the knowledge graph and uses SPARQL query language to interact with the knowledge graph.

Marketing Integration Solution

This is a project based on Node.js, TypeScript, and Serverless on AWS to build an integration solution for online marketplaces like BigCommerce, Google Shopping, Facebook Commerce, and Amazon Marketplace.

Skills

Languages

Snowflake, Java, Python, Scala, Python 3, Java 8, JavaScript, TypeScript, SQL, Go, Swift, Elixir, Erlang (OTP), GraphQL, Rust, Solidity, Assembly, SPARQL, C++, C, Erlang

Frameworks

Serverless Framework, Spark, Apache Spark, Express.js, Next.js, Spring Boot, Flask, Django, React Native, Akka, JSON Web Tokens (JWT), Spring 5, Hadoop, Phoenix

Libraries/APIs

Pandas, BigCommerce API, Facebook API, React, REST APIs, PySpark, Node.js, PyTorch, Web3.js, Natural Language Toolkit (NLTK), SpaCy, Segment.io, GitHub API

Tools

Apache Solr, AWS Glue, Docker Compose, Spark SQL, Git, Apache Airflow, Kafka Streams, GitHub, Amazon Elastic MapReduce (EMR), Amazon EKS, Amazon Cognito, MetaMask, Puppet, Ansible, Helm, GitLab CI/CD

Paradigms

Serverless Architecture, ETL, ETL Implementation & Design, Functional Programming, Service-oriented Architecture (SOA), Agile Software Development, Six Sigma

Platforms

AWS Lambda, Oracle, Linux, Apache Kafka, Docker, Kubernetes, Amazon Web Services (AWS), Azure, Blockchain, Ethereum, Shopify

Storage

Amazon DynamoDB, Elasticsearch, PostgreSQL, MarkLogic, NoSQL, Graph Databases, MySQL/MariaDB, MySQL, MongoDB, Redis

Other

Data Analysis, Common Data Service, Data Warehousing, Serverless, ETL Development, Big Data Architect, Big Data, Natural Language Processing (NLP), Data Analytics, Data Vaults, Data Warehouse Design, Data Engineering, Data Architecture, Software Architecture, Service Meshes, Architecture, Solution Architecture, Algorithms, Fintech, Quantum Computing, Linear Algebra, GPT, Generative Pre-trained Transformers (GPT), Networks, Full-stack, LangChain, OpenAI GPT-3 API, OpenAI GPT-4 API, Artificial Intelligence (AI), APIs, Team Leadership, Remote Team Leadership, Chatbots, Data Migration, Segment, Data Management, CI/CD Pipelines, Amazon Kinesis, Machine Learning, Deep Learning, Solana, Cryptocurrency, DApps, Ethereum Smart Contracts, Non-fungible Tokens (NFT), Smart Contracts, Data Build Tool (dbt), Tokenomics, Tokenization, Token Design, Qiskit Runtime, Q#, Natural Language Understanding (NLU), Ontologies, Stardog, Casbin-Mesh, Business Systems Analysis, Prefect, Google BigQuery, Snowpark, Training, Networking, Quality Auditing, Statistics, Data Quality, Quality Control (QC), Data Quality Management

Education

1994 - 1996

Diploma in Computer Systems Analyst

Accad Institute - Aleppo, Syria

1987 - 1990

Progress Toward a Bachelor's Degree in Mathematics and Physics

Aleppo University - Aleppo, Syria

CompTIA Certification Program

NOVEMBER 2000 - PRESENT

A+

CompTIA Certification Program