Gabriel Breahna, Developer in Bucharest, Romania
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Gabriel Breahna

Verified Expert  in Engineering

Software Developer

Location
Bucharest, Romania
Toptal Member Since
September 15, 2022

Gabriel has 20 years of experience installing, managing, and using SQL, NoSQL (key-value, columnar, graph), time-series, spatial, in-memory, and cloud databases. He's worked with 10TB OLTP databases, 10TB data warehouses, tables with 10+ billion rows, and databases with 10,000+ tables. He's built greenfield and brownfield apps, managed acquisitions, mergers, and spin-offs, and is proficient in Oracle, PostgreSQL, MySQL, Snowflake, BigQuery, Redshift, Synapse, MongoDB, Cassandra, and DynamoDB.

Portfolio

Oracle
SQL, PL/SQL, Oracle Cloud, Oracle HCM Cloud, Oracle Application Express (APEX)...
Freelance Clients
SQL, PL/SQL, Oracle RDBMS, Oracle EBS, Oracle Application Express (APEX)...
Builders Ltd.
SQL, PostgreSQL, Amazon Web Services (AWS), AWS CLI, BigQuery, Shell Scripting...

Experience

Availability

Part-time

Preferred Environment

SQL, Data Warehousing, Data Analytics, Big Data, Databases, Data Engineering, SQL Performance, Data Integration, Business Intelligence (BI), Back-end

The most amazing...

...thing: built queries for funnels, journeys, retentions, insights, for tables with 300 billion records & execution times of 0.2 seconds for 80% of the queries.

Work Experience

Principal Software Developer

2019 - PRESENT
Oracle
  • Built an external candidate scheduling app and integrated it with Oracle HCM Cloud, Microsoft Graph RESTful APIs, Zoom RESTful APIs, and Slack RESTful APIs.
  • Managed, from the database side, the migration of four databases and over 100 apps from being on-premise to Oracle Cloud. Used Oracle Cloud, RDBMS, SQL, PL/SQL, Docker, Terraform, Ansible, Bash, and Linux.
  • Created new ETL pipelines and managed existing ETL pipelines to capture data from various external and internal systems into the OTA data warehouse. Used SQL, PL/SQL, Airflow, Kafka, Spark, Python, ADW, Oracle NoSQL Database Cloud, and Oracle Cloud.
  • Built RESTful APIs, which included exposing tables, procedures, functions, and schemas. Used Oracle REST Data Services (ORDS), OAuth2, SQL, PL/SQL, and cURL.
  • Collaborated with an enterprise ML team to develop multiple algorithms to classify candidate resumes.
  • Worked with the Java team to expose the endpoints for the front-end team. SQL and PL/SQL made up the primary tech stack.
  • Constructed green-field and brown-field Oracle APEX apps for the OTA organization. Used SQL, PL/SQL, HTML, CSS, JavaScript, OJET, and ORDS.
  • Performed SQL tuning for poorly performing apps. Used the explain plan, execution plan, and performance statistics and worked with DBAs, sysadmins, the product development team, and expert gurus.
  • Reviewed code and implemented pair programming, all within an Agile environment.
Technologies: SQL, PL/SQL, Oracle Cloud, Oracle HCM Cloud, Oracle Application Express (APEX), Data Warehousing, Back-end Development, Microsoft Graph API, Slack API, Zoom, Agile, HTML, JavaScript, CSS, JSON, OAuth 2, Data Encryption, Oracle REST Data Services (ORDS), Oracle JavaScript Extension Toolkit (JET), Docker, Docker Compose, Oracle Performance Tuning, Terraform, Ansible, Jenkins, Git, Slack, Slack App, cURL Command Line Tool, Postman, Bash, Linux, DevOps, Column-oriented DBMS, Oracle, Migration, REST APIs, Data Lakes, Snowflake, RDBMS, Databases, Data Pipelines, Data Engineering, APIs, Azure, Oracle VM VirtualBox, Oracle E-Business Suite (EBS), Oracle PL/SQL, Oracle SQL, Software as a Service (SaaS), Oracle Database, Oracle Cloud Infrastructure (OCI), Oracle SOA Suite, SQL Loader, Data Center Migration, Data Architecture, Data Modeling, Database Security, Star Schema, Data Processing Automation, Microsoft Excel, Data Processing, CSV, Data Analysis, Scripting, ETL Tools, User Experience (UX), User Interface (UI), Data Science, Data Visualization, Consulting, Mobile Analytics, Data Analytics, Data Cleaning, Financial Modeling, Database Optimization, Dimensional Modeling, Oracle Business Intelligence Enterprise Edition 11g (OBIEE), Query Optimization, Performance Tuning, Query Composition, Back-end, Analytics, Database Architecture, Relational Database Design, Stored Procedure, SQL Stored Procedures, Database Schema Design, SaaS, Apache Kafka, Kafka Streams, Apache Airflow, Spark, Apache Hive, Datasets, Data Cleansing, Data Profiling, Dashboards, Data Reporting, BI Reporting, Robotic Process Automation (RPA), Oracle Database Architecture, Docker Cloud, CI/CD Pipelines, Enterprise Resource Planning (ERP), Microsoft Power Automate, API Design, ODBC, Database Design, Database Structure, Database Transactions, Transactions, OLTP, Big Data, Message Queues, Big Data Architecture, Data Transformation, Amazon EC2, Database Performance, Node.js, Networks, SQL Triggers, Oracle DBA, Database Development, Data Integration, Streaming Data, Unix, Data, Solution Architecture, Data Auditing, Monitoring, Technical Architecture, Microsoft Power Apps, Database Modeling, ELT, Process Automation, Pipelines, Architecture, Automation, Algorithms, Interactive Dashboards, Reports, Microservices, Graph API, Integration, GitHub, RabbitMQ, Microsoft 365, Proof of Concept (POC), Database Migration, ETL Development, ETL Implementation & Design, ETL Testing, Oracle Fusion Applications, Oracle Security Server, Identity & Access Management (IAM), Backup & Recovery, Performance Optimization, Leadership, Master Data Management (MDM), ETL Pipelines, Database Lifecycle Management (DLM), Business to Business (B2B), Delta Lake, SSH, Data Migration, Cloud Migration, MQTT, API Integration, REST, Business Requirements, DB, Data Flows, Distributed Systems, Scalability, Git Repo, Static Analysis, Shell Scripting, Machine Learning

Software Engineer | Data Engineer

2016 - PRESENT
Freelance Clients
  • Created batch-and-streaming Google Cloud Dataflow pipelines/DAG to insert data from 4,000+ IoT devices into a 10TB Goole BigQuery data warehouse. Used GCP console and Python for the job and extracted data via BigQuery and SQL.
  • Refactored a GPS tracking application from Oracle RDBMS, Oracle APEX, and GlassFish to an open-source solution based on PostgreSQL, Python, Bootstrap, and OpenStreetMap tiles. Used SQL, Python, Flask, Bootstrap, HTML, CSS, JavaScript, and Leaflet.
  • Migrated a GPS tracking application hosting 2,000+ GPS devices from an Oracle RDBMS-based solution to an open-source solution based on Traccar Java-based application and PostgreSQL RDBMS.
  • Migrated a data center from on-premise to OVHcloud bare-metal servers, Linux, Apache Tomcat, GlassFish, NGINX, Oracle RDBMS, Oracle APEX, PostgreSQL, and Python. Provisioned Linux boxes. Installed and configurated Linux and Oracle RDBMS.
  • Architected the solution, created ETL pipelines, and developed SQL code for 10TB of data generated at a Euro 6 emission test time. Used GCP BigQuery, Dataflow, Apache Beam, streaming/batch pipeline, Pub/Sub, Cloud Functions, and Cloud Storage.
  • Developed a GPS tracking device, including the firmware using C and the integration into the Traccar app. It was manufactured at PCBWay.com at a very affordable price. Used STM32F4 microcontroller, STM32CubeMX, and KiCad.
  • Built a 6DOF robotic arm using mechanical parts from a Borunte robot and added new Inovance servo drivers. Used SOEM open source, extending it using real-time C programming. Created a ROS control driver and MoveIt trajectory control.
  • Localized the Odoo/OpenERP for the Romanian market, which included building modules, reports, and enhanced forms. Sold the service as a SaaS. Used Python, Selenium, PostgreSQL, SQL, Docker, and OVHcloud.
  • Developed a data warehouse for a Romanian holding to consolidate its operations from distribution, manufacturing, wholesale, and retail, from multiple ERPs inherited after multiple acquisitions, using Azure, Synapse, Data Factory, and PowerBI.
  • Conducted multiple one- to six-month-long freelance projects as a software and data engineer using a wide range of technologies such as AWS, Azure, GCP, Snowflake, Redshift, PostgreSQL, MySQL, Airflow, Python, Lambda, Kafka, CDC, dbt, EKS, and MKS.
Technologies: SQL, PL/SQL, Oracle RDBMS, Oracle EBS, Oracle Application Express (APEX), Docker, Jenkins, Google BigQuery, Cloud Dataflow, Apache Beam, Python, Flask, PostgreSQL, SQLAlchemy, Leaflet, Mapbox GL, OpenStreetMap, Nominatim, Pandas, Plotly, C, Matplotlib, HTML, CSS, JavaScript, JSON, jQuery, OAuth 2, Data Encryption, Terraform, Ansible, Docker Compose, Data Centers, Data Center Migration, NGINX, GlassFish, Apache Tomcat, Directed Acrylic Graphs (DAG), Oracle REST Data Services (ORDS), MySQL, SQLite, cURL Command Line Tool, Postman, EtherCAT, Arduino IDE, Arduino, STM32CubeMX, Robot Operating System (ROS), Selenium, Git, Slack, Jira, Confluence, Nextcloud, DevOps, Windows, MacOS, OVH, Cloud, RESTful Microservices, MongoDB, MariaDB, Column-oriented DBMS, Oracle Cloud Infrastructure (OCI), JSON Web Tokens (JWT), XPath, XQuery, XSLT, Oracle, Migration, REST APIs, Snowflake, RDBMS, Databases, Data Pipelines, BigQuery, Data Engineering, Google Cloud Platform (GCP), OLAP, APIs, Tableau, Microsoft Power BI, Azure, Oracle VM VirtualBox, KiCad, PyCharm, Altium Designer (PCAD), RS485, RS-232, Modbus Protocol, Odoo, OpenERP, XML, Oracle E-Business Suite (EBS), Oracle PL/SQL, Oracle SQL, Software as a Service (SaaS), Oracle Database, Oracle SOA Suite, SQL Loader, IT Project Management, Data Architecture, Data Modeling, Microsoft SQL Server, Database Security, Relational Databases, Star Schema, Data Processing Automation, Microsoft Excel, Data Processing, CSV, Data Analysis, Scripting, ETL Tools, Blockchain Platforms, User Experience (UX), User Interface (UI), Data Science, Amazon Web Services (AWS), Data Visualization, Apache Airflow, Django, Amazon RDS, Consulting, AWS Lambda, GraphQL, Mobile Analytics, Redshift, Firebase, Data Analytics, Data Cleaning, Financial Modeling, Database Optimization, Consumer Packaged Goods (CPG), Dimensional Modeling, Oracle Cloud, Oracle Business Intelligence Enterprise Edition 11g (OBIEE), Query Optimization, Performance Tuning, Query Composition, Back-end, Analytics, Database Architecture, Relational Database Design, Data Build Tool (dbt), XML for Analysis (XMLA), Stored Procedure, SQL Stored Procedures, Cron, Database Schema Design, SaaS, B2B, Datasets, Data Cleansing, Data Profiling, Dashboards, Supply Chain, Data Reporting, BI Reporting, Business Services, Apache Spark, Oracle Database Architecture, Oracle 10g, Kubernetes, Docker Cloud, Data Governance, CI/CD Pipelines, Enterprise Resource Planning (ERP), SAP, SAP S/4HANA, API Design, Power Query, DAX, ODBC, AWS Glue, Database Design, Database Structure, Database Transactions, Transactions, Search, Geospatial Data, OLTP, Google Analytics, Big Data, Message Queues, Big Data Architecture, Data Transformation, Amazon Athena, Amazon EC2, Database Performance, Node.js, Networks, Google Cloud Functions, SQL Triggers, MySQL Server, Oracle DBA, Database Development, Hadoop, Data Integration, Streaming Data, Unix, Database Administration (DBA), Data, Azure Data Factory, Solution Architecture, Data Auditing, Monitoring, Technical Architecture, Azure SQL Data Warehouse, Dedicated SQL Pool (formerly SQL DW), Microsoft Power Automate, Microsoft Power Apps, Sourcing & Procurement, Database Modeling, ELT, Process Automation, Pipelines, Architecture, Amazon S3 (AWS S3), Data Lakes, Automation, Algorithms, Interactive Dashboards, Reports, Microservices, Graph API, Fivetran, LinkedIn API, Google API, Sage 300 SDK, QuickBooks API, Stripe API, Spotify API, GitHub API, Instagram API, Twitter API, Facebook API, YouTube API, Integration, GitHub, RabbitMQ, Microsoft 365, Proof of Concept (POC), Database Migration, ETL Development, ETL Implementation & Design, ETL Testing, T-SQL (Transact-SQL), Backup & Recovery, pgAdmin, Performance Optimization, Leadership, Looker, Google Cloud, Google Analytics 4, Accounting, Master Data Management (MDM), ETL Pipelines, Database Lifecycle Management (DLM), eCommerce, Spotify, Twitter, TikTok, Business to Business (B2B), Delta Lake, Databricks, Spark SQL, SSH, Data Migration, Cloud Migration, Mixpanel, Segment.io, Geospatial Analytics, User Journeys, Web Marketing, IoT Protocols, Internet of Things (IoT), TCP/IP, MQTT, API Integration, WebSockets, AWS IoT, C#, Debian, REST, Business Requirements, Django ORM, Django REST Framework, Industry 4.0, Smart City Technology, Microcontrollers, J1939, Data Center Management, LoRaWAN, LoRa, CIM, Relux, Autodesk Fusion 360, SOLIDWORKS, MATLAB, Simulink, Sequelize, DB, Data Flows, Distributed Systems, Startups, Scalability, Git Repo, Static Analysis, Shell Scripting, Google Pub/Sub, Apache, PySpark, Machine Learning

Database Engineer

2024 - 2024
Builders Ltd.
  • Fixed the AWS RDS PostgreSQL performance issue, lowering it from 100% to 30%, reducing execution time from minutes to under one second.
  • Enhanced the back-end app (Node.js/TypeScript) to deal with mint/burnt tokens.
  • Upgraded FTSO Flare/Songbird FTSO apps (Node.js/TypeScript) to the latest ccxt library and fixed miscellaneous bugs along the process. Streamed all recorded data into BigQuery for later ML processing.
Technologies: SQL, PostgreSQL, Amazon Web Services (AWS), AWS CLI, BigQuery, Shell Scripting, Google Cloud Platform (GCP), Machine Learning

Software Engineer | Data Engineer

1999 - 2016
Euro Bit SA
  • Implemented Oracle EBS 12.2 financials, order management, procurement, supply chain planning, and manufacturing.
  • Served as an app admin, DBA, and SQL developer, which included SQL performance/tuning and management, developing SQL and PL/SQL customizations and reports.
  • Built a vehicle spare parts webshop tightly integrated with Oracle EBS R12. Used Oracle RDBMS, Oracle APEX, ORDS, HTML, JavaScript, CSS, and jQuery. Integrated it also with TecDoc via RESTful API and OAuth2.
  • Led the build of a SaaS model GPS vehicle-tracking app and used Oracle RDBMS, Oracle APEX, HTML, CSS, JavaScript, LeafletJS, jqPlot, Apache Tomcat, and OpenStreetMap. It oversaw 10,000+ GPS units, 10TB of data, and 20 billion records at its peak.
  • Crafted a customized putaway and picking algorithm for the Oracle EBS WMS and MSCA module. Used SQL, PL/SQL, and Java. WMS was used to manage a 500,000-square-foot warehouse, and the algorithm increased overall efficiency by 10%.
  • Constructed a customized EDI integration module for Oracle EBS order management, shipping, and purchasing. Used SQL, PL/SQL, EDI, iDoc, XML, and JSON. At its peak, the system managed 5,000 orders/day and one million orders/year.
  • Developed a driver for Datecs ECR to integrate it with Odoo/OpenERP. Used Qt.
  • Made business intelligence dashboards and reports based on Oracle EBS data. Used SQL, Oracle OBIEE, and Weblogic.
  • Developed 20+ Oracle EBS extensions using Oracle APIs, interfaces, SOA, XML, a RESTful API, APEX, SQL, PL/SQL, SQL Loader, and SFTP.
Technologies: SQL, PL/SQL, Oracle RDBMS, Oracle EBS, Oracle Application Express (APEX), Java, Python, C++, C, Data Warehouse Design, Business Intelligence (BI), Electronic Data Interchange (EDI), ETL, TecDoc, OAuth 2, Oracle Discoverer, Oracle Reports, Oracle REST Data Services (ORDS), Odoo, OpenERP, Qt, SAP IDoc, XML, JSON, Oracle Business Intelligence Enterprise Edition 11g (OBIEE), Oracle WebLogic Application Server, Git, SQL Server Analysis Services (SSAS), Solaris, Linux, Windows, Oracle SOA Suite, SFTP, SQL Loader, Leaflet, jqPlot, Oracle, Migration, REST APIs, Snowflake, RDBMS, Databases, Data Pipelines, Data Engineering, OLAP, APIs, Tableau, Microsoft Power BI, Relational Data Mapping, Oracle VM VirtualBox, RS485, RS-232, Modbus Protocol, jQuery, Oracle E-Business Suite (EBS), Oracle PL/SQL, Oracle SQL, Software as a Service (SaaS), Oracle Database, Data Center Migration, IT Project Management, Data Architecture, Data Modeling, Microsoft SQL Server, Database Security, Relational Databases, Star Schema, Data Processing Automation, Microsoft Excel, Data Processing, CSV, Data Analysis, Scripting, ETL Tools, User Experience (UX), User Interface (UI), Data Science, Data Visualization, Consulting, Mobile Analytics, Data Analytics, Data Cleaning, Borland Database Engine (BDE), Financial Modeling, Database Optimization, Consumer Packaged Goods (CPG), Query Optimization, Performance Tuning, Query Composition, Back-end, Analytics, Database Architecture, Relational Database Design, XML for Analysis (XMLA), Stored Procedure, SQL Stored Procedures, Cron, Database Schema Design, SaaS, Datasets, Data Cleansing, Data Profiling, Dashboards, Supply Chain, Data Reporting, BI Reporting, Oracle Database Architecture, Oracle 10g, Data Governance, Enterprise Resource Planning (ERP), SAP, SAP S/4HANA, Digital Manufacturing, API Design, Power Query, DAX, ODBC, AWS Glue, Database Design, Database Structure, Database Transactions, Transactions, Search, Real Estate, Geospatial Data, OLTP, Google Analytics, Big Data, Message Queues, Big Data Architecture, Data Transformation, Amazon Athena, Amazon Elastic MapReduce (EMR), Scala, Database Performance, Node.js, Networks, Google Cloud Functions, Microsoft Access, SQL Triggers, MySQL Server, Oracle DBA, Database Development, Data Integration, Streaming Data, NoSQL, Oracle 11g, Unix, Database Administration (DBA), VMware, Data Guard, IIS SQL Server, Data, Azure Data Factory, Solution Architecture, Data Auditing, Industrial Internet of Things (IIoT), Monitoring, Technical Architecture, Ajax, Azure SQL Data Warehouse, Dedicated SQL Pool (formerly SQL DW), Sourcing & Procurement, Database Modeling, ELT, Process Automation, Pipelines, Architecture, Amazon S3 (AWS S3), Amazon Web Services (AWS), Automation, OCR, Algorithms, Interactive Dashboards, Reports, Microservices, MySQL DBA, Graph API, Fivetran, LinkedIn API, Google API, Sage 300 SDK, QuickBooks API, Integration, GitHub, RabbitMQ, Microsoft 365, Proof of Concept (POC), Database Migration, ETL Development, ETL Implementation & Design, ETL Testing, T-SQL (Transact-SQL), Oracle Fusion Applications, Oracle Security Server, Identity & Access Management (IAM), Veeam, Backup & Recovery, VMware vSphere, Network Engineering, Software-defined WAN (SDWAN), Data Center Infrastructure, Networking, pgAdmin, Performance Optimization, Leadership, Google Cloud, Google Analytics 4, Accounting, Master Data Management (MDM), ETL Pipelines, Database Lifecycle Management (DLM), eCommerce, Business to Business (B2B), Delta Lake, Databricks, Spark SQL, SSH, Data Migration, Cloud Migration, Geospatial Analytics, Web Marketing, IoT Protocols, Internet of Things (IoT), TCP/IP, MQTT, API Integration, WebSockets, AWS IoT, C#, Azure IoT Edge, ESP32, C#.NET, Raspberry Pi, Debian, Azure IoT Suite, REST, Business Requirements, Industry 4.0, Smart City Technology, Microcontrollers, J1939, Data Center Management, Autodesk Fusion 360, SOLIDWORKS, MATLAB, Simulink, JavaScript, Sequelize, DB, Data Flows, Distributed Systems, Startups, Scalability, Git Repo, Static Analysis, Shell Scripting, Google Pub/Sub, Google Cloud Platform (GCP), Apache, PySpark

IT Manager | Project Manager | Developer

1996 - 1999
Euro Trade Invest SA
  • Developed a tailored application for an alcohol plant from scratch and integrated it with SCADA and other sensors; used Oracle RDBMS, Borland Delphi, and C.
  • Built an app for a chain of 16 duty-free shops using Orale Personal Edition and Borland Delphi.
  • Constructed a fiscal printer driver with bidirectional communication with the main POS; used C and C++.
Technologies: SQL, PL/SQL, Oracle RDBMS, C, C++, Pascal, SCADA, IT Project Management, Databases, Data Pipelines, Oracle PL/SQL, Oracle SQL, Data Architecture, Data Modeling, Microsoft Excel, CSV, Consulting, Borland Database Engine (BDE), Financial Modeling, Database Optimization, Consumer Packaged Goods (CPG), Data Analysis, Query Composition, Oracle Database Architecture, Database Design, Database Structure, Database Transactions, Transactions, OLTP, Networks, Data, Solution Architecture, Proof of Concept (POC), Performance Optimization, Leadership, Database Lifecycle Management (DLM), Data Migration, Business Requirements, DB, Distributed Systems

Software Engineer

1995 - 1996
TAROM SA
  • Created new ETL pipelines and maintained existing pipelines for data coming from 30+ agencies abroad; used Borland C++.
  • Integrated the Boeing Spare Parts electronic catalog with the airliner purchasing system using Borland C++.
  • Cleaned up OTP Airport passengers' onboarding data and reused that data to generate the annual TAROM airliner timetable; it was done using Borland Delphi.
Technologies: C++, ETL, PL/SQL, Oracle RDBMS, Pascal, Borland Database Engine (BDE), Database Optimization, Query Composition, Database Schema Design, Database Design, Database Structure, Database Transactions, Transactions, OLTP, Data, Proof of Concept (POC), Performance Optimization, Master Data Management (MDM), Database Lifecycle Management (DLM), Data Migration, Business Requirements, DB, Distributed Systems

Software Engineer

1994 - 1995
ITC SA
  • Developed a custom dispatching app for a small taxi company based on Oracle 7.3 and Borland C++.
  • Oversaw and was responsible for software maintenance across the codebase. This required a wide understanding of the internals of the software and systems.
  • Developed a custom app for the accounting department based on their ongoing specs using Visual FoxPro.
Technologies: SQL, C++, PL/SQL, Oracle RDBMS, Borland Database Engine (BDE), Query Composition, Database Schema Design, Oracle Database Architecture, Database Design, Database Structure, Database Transactions, Transactions, OLTP, Data, Proof of Concept (POC), Performance Optimization, Database Lifecycle Management (DLM), Data Migration, Business Requirements, DB

Amazon RDS PostgreSQL Optimization

https://xhaven.io
I optimized an Amazon RDS PostgreSQL database with a CPU load of 100% most of the time. My work also included fixing queries, creating missing indexes, changing database parameters, and changing the Sequelize Node.js code in the back end. I used CloudWatch, Performance Insights, the PostgreSQL PERF profiling utility, and EXPLAIN ANALYZE.

In the end, the average database load dropped to 10%, with no spikes.

Digital Analytics Tool Based on BigQuery and TypeScript

http://livedocs.com
As the lead back-end developer for a cutting-edge SaaS digital analytics app, I spearheaded the development of a dynamic platform capable of seamlessly integrating data from various sources using APIs and database connections. My role involved crafting intricate analytic queries tailored for BigQuery, leveraging TypeScript to develop custom plugins for Fivetran, and fine-tuning the performance of our PostgreSQL database hosted on the Google Cloud Platform (GCP). With a focus on efficiency and scalability, I played a pivotal role in enabling our users to generate insightful queries, reports, and data applications in a matter of seconds.

Digital Analytics Platform Based on Snowflake, BigQuery, and Redshift

I created SQLs for user and event segmentation, funnels, journeys, and retentions, using SQL and JavaScript UDTFs to deal with 300 million monthly records.

I used clustering, materialized views, and pre-aggregations to improve query execution time. A proprietary BQL language was created for easy interaction between the front and back ends. I made a BQL to SQL transpiler using Go, ANTLR4, AWS DynamoDB, AWS RDS Postgres, and AWS MSK, and a proprietary ingestion system using Go, Python, AWS Lambda, AWS EKS, Rudderstack, and Segment.

Compressed Natural Gas 12.4 Liter Heavy-duty Engine EURO VI Emission Certifications

I created a data warehouse that could manage ten TB of data generated in a couple of weeks under a very tight working schedule.
My process started by using an Oracle database configured as a data warehouse on-premise. I then used SQL and PL/SQL for the ETL and SQL for extracting the data.
Next, I performed a lot of SQL tuning for performance enhancement. Further improvements included implementing an Oracle Cloud-based data warehouse, along with cloud-specific tools. I also implemented Google Cloud and BigQuery and created Apache Beam DAG pipelines to increase the ETL speed.
We received two certifications for a 380 and 460 horse-power engine family.

Automotive Spare Parts Webshop

This project involved an Oracle APEX app that was tightly integrated with Oracle EBS R12. The app's purpose was to sell vehicle spare parts, deal with seeded and superseded spare parts, and expose 10 million parts.

My work included an integration via a RESTful API while using Express Carriers for shipping. I also integrated RESTful APIs with vehicle spare parts suppliers for quick replenishment and created RESTful microservices tailored for key customers.

My technology stack included Oracle RDBMS, APEX, Oracle REST Data Services (ORDS), SQL, PL/SQL, RESTful APIs, microservices, and Docker Compose.

Oracle EBS Implementation, Personalization, Customization, Extension, Workflow, and Analytics

I completed 10+ Oracle EBS implementations in financials, SCM, WMS, manufacturing, and services. I improved the system by making personalization and customizations. I also created extensions using APEX and introduced workflow changes.

I created a custom data warehouse, custom mobile data warehouse apps, EDI integrations with key accounts, B2B and B2C apps, integrations with express delivery companies, integration with POS and weighting scales, conveyors using CANopen, integrations with packaging and bottling lines, dock management, yard management, and fleet management. I implemented Power BI and Tableau analytics on Snowflake, BigQuery, RedShift, and Oracle ADW.

Database Migration for a Fintech Company

I performed MS SQL Server to Oracle migration for multiple database instances, which the customer inherited after multiple acquisitions. I also conducted database analysis, and application code, performed data types mapping, and modified stored procedures, triggers, and queries.

I worked on ensuring data integrity and compatibility, performed query optimization, and evaluated online and offline data migration to minimize downtime. With all of this, I also performed tests and validations. The customer preferred a SQL script approach and manually assisted.

Vehicle GPS Tracking SaaS Application

This project involved a Python Flask and PostgreSQL-based SaaS application meant for tracking vehicles via GPS. At the time, it managed over 10,000 vehicles, 10TB of data, and 20 billion records.

Initially, the app was built using Oracle APEX and Oracle RDBMS on-premise. Still, later on, we migrated it to OVH Cloud and, after a while, refactored it using only open source technologies such as OpenStreetMap for map tiles, geocoding, reverse geocoding, Traccar.org for GPS tracking, PostgreSQL, and Python.

It was a real challenge to make it run fast because of the huge amount of data, but we accomplished it via various SQL techniques.

We launched the app in 2008, and it is still working today.

External Candidate Database Scheduling Engine

I built a 100% PL/SQL scheduling engine integrated with the organization's Microsoft Exchange 365 Calendar Service.

I used PL/SQL, UTL_HTTP, wallets, Cloud Vault, and Microsoft Graph RESTful APIs for the calendar, mail, and attachments, along with Zoom and Slack APIs, OAuth2, and pre-authentication. I also solved performance issues for a 100,000+ users organization and an undisclosed number of booked meetings per day.

Custom Algorithms for an Oracle EBS 3PL Data Warehouse

I created pure SQL and PL/SQL algorithms as an extension for the Oracle EBS Warehouse module, which was meant for a 3PL implementation. It was a 500,000-square-foot warehouse with a wide variety of products (electronic appliances, food, beverages, cigarettes, raw materials, and meat) and several custom specs for receiving and shipping along with 20,000+ SKUs, 5,000+ orders per day, and 25,000+ order lines per day.

The successful implementation made the end users happy, and the client could get contracts signed with all prominent players from the local market.

Open-source ERP and Odoo Romanian Localization

I created 20+ Odoo apps/modules and ensured that they complied with Romanian regulations.

My work included creating a bill printer, XML receipts, VAT customization, currency rate updates, Romanian invoices, MRP costs, key accounts' SKUs, POS debranding, printer ZPL 2, stock analyses, stock expiration dates, and Romanian stock reports.

I used Python, XPath with QWeb, PostgreSQL, and SQL.
1989 - 1994

Master of Science Degree in Industrial Engineering and Robotics

University Politehnica of Bucharest - Bucharest, Romania

OCTOBER 2023 - PRESENT

Cyber Security Auditor

Romanian Directorate for Cyber Security

MARCH 2021 - SEPTEMBER 2022

Oracle Cloud Infrastructure Foundations 2020 Certified Associate

Oracle

JUNE 2018 - MAY 2021

PRINCE2 Practitioner

AXELOS

Libraries/APIs

REST APIs, ODBC, Graph API, Segment.io, PySpark, Leaflet, Mapbox GL, Slack API, Node.js, QuickBooks API, Stripe API, Spotify API, GitHub API, Instagram API, Twitter API, Facebook API, YouTube API, LinkedIn API, Google API, Django ORM, SQLAlchemy, Pandas, Matplotlib, jQuery, jqPlot

Tools

AutoCAD, Oracle Application Express (APEX), Oracle Business Intelligence Enterprise Edition 11g (OBIEE), Git, Jira, Slack, Confluence, Zoom, Oracle Reports, Oracle E-Business Suite (EBS), BigQuery, Tableau, Microsoft Power BI, Microsoft Excel, Apache Airflow, Cron, ANTLR 4, AWS IAM, AWS CLI, AWS Key Management Service (KMS), AWS Glue, Microsoft Access, GitHub, RabbitMQ, pgAdmin, Looker, Spark SQL, MQTT, Sequelize, PyCharm, Apache Tomcat, Docker Compose, TecDoc, Odoo, Oracle SOA Suite, Kafka Streams, Power Query, Google Analytics, Amazon Athena, Amazon Elastic MapReduce (EMR), VMware, Data Guard, Microsoft Power Apps, Sage 300 SDK, VMware vSphere, Azure IoT Suite, Autodesk Fusion 360, MATLAB, Apache, Jenkins, Cloud Dataflow, Apache Beam, Plotly, EtherCAT, Altium Designer (PCAD), KiCad, Terraform, Ansible, NGINX, cURL Command Line Tool, Postman, Amazon EKS, SAP S/4HANA, Amazon CloudWatch, Relux, SOLIDWORKS

Frameworks

OAuth 2, Flask, JSON Web Tokens (JWT), Django, Apache Spark, Django REST Framework, Oracle JavaScript Extension Toolkit (JET), Qt, Selenium, QWeb, Spark, Hadoop

Languages

SQL, Python, JavaScript, Snowflake, Stored Procedure, T-SQL (Transact-SQL), C, C++, Java, Bash, Go, C#, C#.NET, Simulink, Pascal, HTML, CSS, XML, XPath, XQuery, XSLT, GraphQL, Scala

Paradigms

ETL, Business Intelligence (BI), Dimensional Modeling, B2B, Oracle Database Architecture, Database Design, Database Development, Automation, Microservices, ETL Implementation & Design, REST, OLAP, Agile, DevOps, Data Science

Platforms

Docker, Linux, Oracle Database, Oracle, Google Cloud Platform (GCP), Amazon Web Services (AWS), AWS Lambda, Unix, Databricks, Mixpanel, AWS IoT, Debian, Solaris, OpenERP, Windows, MacOS, Oracle Cloud Infrastructure (OCI), Azure, Apache Kafka, Kubernetes, Microsoft Power Automate, Amazon EC2, Azure SQL Data Warehouse, Twitter, Raspberry Pi, Dedicated SQL Pool (formerly SQL DW), Arduino, Blockchain Platforms, Firebase

Storage

PL/SQL, Oracle RDBMS, PostgreSQL, SQL Performance, JSON, MySQL, Oracle SQL, Oracle PL/SQL, SQL Loader, RDBMS, Databases, Data Pipelines, Microsoft SQL Server, Database Security, Relational Databases, Database Architecture, SQL Stored Procedures, Amazon S3 (AWS S3), Oracle 10g, Database Structure, Database Transactions, OLTP, Database Performance, SQL Triggers, MySQL Server, Oracle DBA, Data Integration, Oracle 11g, Database Administration (DBA), Database Modeling, Database Migration, Google Cloud, Master Data Management (MDM), Database Lifecycle Management (DLM), DB, Oracle Cloud, Data Centers, SQLite, Nextcloud, SQL Server Analysis Services (SSAS), OVH, MariaDB, Column-oriented DBMS, Data Lakes, Docker Cloud, NoSQL, IIS SQL Server, MongoDB, Redshift, Apache Hive, Amazon DynamoDB, Elasticsearch

Industry Expertise

Accounting

Other

Data Warehousing, Oracle EBS, Oracle Performance Tuning, IT Project Management, Data Warehouse Design, Electronic Data Interchange (EDI), Back-end Development, Google BigQuery, Oracle VM VirtualBox, Microsoft Graph API, Data Center Migration, Oracle Discoverer, Oracle REST Data Services (ORDS), Cloud, Software as a Service (SaaS), Migration, Data Engineering, APIs, Data Architecture, Data Modeling, Star Schema, Data Processing Automation, Data Processing, CSV, Data Analysis, Scripting, ETL Tools, Data Visualization, Amazon RDS, Consulting, Data Analytics, Data Cleaning, Borland Database Engine (BDE), Financial Modeling, Database Optimization, Consumer Packaged Goods (CPG), Query Optimization, Performance Tuning, Query Composition, Back-end, Analytics, Relational Database Design, XML for Analysis (XMLA), Database Schema Design, SaaS, Datasets, Data Cleansing, Data Profiling, Dashboards, Supply Chain, Data Reporting, Data Migration, BI Reporting, Business Services, Enterprise Resource Planning (ERP), API Design, Transactions, Geospatial Data, Big Data, Message Queues, Big Data Architecture, Data Transformation, Google Cloud Functions, Data, Solution Architecture, Data Auditing, Industrial Internet of Things (IIoT), Monitoring, Technical Architecture, Ajax, Sourcing & Procurement, ELT, Process Automation, Pipelines, Architecture, OCR, Algorithms, Interactive Dashboards, Reports, Fivetran, MySQL DBA, Integration, Microsoft 365, Proof of Concept (POC), ETL Development, ETL Testing, Oracle Fusion Applications, Oracle Security Server, Identity & Access Management (IAM), Veeam, Backup & Recovery, Network Engineering, Software-defined WAN (SDWAN), Data Center Infrastructure, Networking, Performance Optimization, Leadership, ETL Pipelines, eCommerce, Business to Business (B2B), Delta Lake, SSH, Cloud Migration, Geospatial Analytics, User Journeys, Web Marketing, IoT Protocols, Internet of Things (IoT), TCP/IP, API Integration, WebSockets, Business Requirements, Data Center Management, J1939, Data Flows, Distributed Systems, Startups, Scalability, Git Repo, Static Analysis, Shell Scripting, Google Pub/Sub, Machine Learning, Oracle HCM Cloud, OpenStreetMap, GlassFish, Data Encryption, Slack App, Oracle WebLogic Application Server, SFTP, Relational Data Mapping, User Experience (UX), Mobile Analytics, Financial Data, Robotic Process Automation (RPA), Data Governance, CI/CD Pipelines, DAX, Search, Networks, Streaming Data, Azure Data Factory, Google Analytics 4, Spotify, TikTok, Azure IoT Edge, ESP32, CIM, LoRa, LoRaWAN, Microcontrollers, SCADA, Nominatim, Modbus Protocol, RS-232, RS485, Directed Acrylic Graphs (DAG), Arduino IDE, STM32CubeMX, Robot Operating System (ROS), SAP IDoc, RESTful Microservices, EDIFACT, User Interface (UI), Data Build Tool (dbt), Amazon Marketing Services (AMS), Customer Data Platform (CDP), Change Data Capture, Segment, SAP, Digital Manufacturing, Real Estate, IT Audits, Audits, Profiling, Smart City Technology, Industry 4.0, HadoopXML

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