Verified Expert in Engineering
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.
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.
Principal Software Developer
- 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.
- 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.
Software Engineer | Data Engineer
- 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.
- 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.
Software Engineer | Data Engineer
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.
- 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.
IT Manager | Project Manager | Developer
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++.
- 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.
- 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.
Digital Analytics Platform Based on Snowflake, BigQuery, and Redshift
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
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
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 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 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
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 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
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
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.
REST APIs, ODBC, Graph API, Leaflet, Mapbox GL, Slack API, OCI, Node.js, QuickBooks API, Stripe API, Spotify API, GitHub API, Instagram API, Twitter API, Facebook API, YouTube API, LinkedIn API, Google API, SQLAlchemy, Pandas, Matplotlib, jQuery, jqPlot
Oracle Application Express (APEX), Oracle Business Intelligence Enterprise Edition 11g (OBIEE), Git, Jira, Slack, Confluence, Zoom, Oracle Reports, Oracle E-Business Suite (EBS), Tableau, Microsoft Power BI, Microsoft Excel, Apache Airflow, Cron, ANTLR 4, AWS CLI, AWS Glue, Microsoft Access, PyCharm, Apache Tomcat, Docker Compose, TecDoc, Odoo, Oracle SOA Suite, Kafka Streams, AWS Key Management Service (KMS), Power Query, Google Analytics, Amazon Athena, Amazon Elastic MapReduce (EMR), VMware, Data Guard, Microsoft Power Apps, Sage 300 SDK, AutoCAD, Jenkins, Cloud Dataflow, Apache Beam, Plotly, EtherCAT, Altium Designer (PCAD), KiCad, Terraform, Ansible, NGINX, cURL Command Line Tool, Postman, BigQuery, AWS IAM, Amazon EKS, SAP S/4HANA
ETL, Business Intelligence (BI), Dimensional Modeling, B2B, Oracle Database Architecture, Database Design, Database Development, Automation, Microservices, OLAP, Agile, DevOps, Data Science
Docker, Linux, Oracle Database, Oracle, Google Cloud Platform (GCP), Amazon Web Services (AWS), AWS Lambda, Unix, Solaris, OpenERP, Windows, MacOS, Azure, Apache Kafka, Kubernetes, Amazon EC2, Arduino, Blockchain Platforms, Firebase
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, Oracle 10g, Database Structure, Database Transactions, OLTP, Database Performance, SQL Triggers, MySQL Server, Oracle DBA, Data Integration, Oracle 11g, Database Administration (DBA), Database Modeling, Oracle Cloud, Data Centers, SQLite, Nextcloud, SQL Server Analysis Services (SSAS), OVH, MariaDB, Column-oriented DBMS, Data Lakes, Amazon S3 (AWS S3), Docker Cloud, NoSQL, IIS SQL Server, MongoDB, Redshift, Apache Hive, Amazon DynamoDB, Elasticsearch
Data Warehousing, Oracle EBS, Oracle Performance Tuning, IT Project Management, Data Warehouse Design, 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, 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, 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, Microsoft Power Automate, DAX, Search, Networks, Streaming Data, Azure Data Factory, Azure SQL Data Warehouse (SQL DW), 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), Data Migration, Amazon Marketing Services (AMS), Customer Data Platform (CDP), Change Data Capture, Segment, SAP, Digital Manufacturing, Real Estate
Master of Science Degree in Industrial Engineering and Robotics
University Politehnica of Bucharest - Bucharest, Romania
Oracle Cloud Infrastructure Foundations 2020 Certified Associate