Selahattin Hancer
Verified Expert in Engineering
Data Engineer and Developer
Selahattin is a data engineer, database administrator, and software developer with over 15 years of industry experience. Throughout his career, he has managed mission-critical databases and built data platforms. Selahattin is passionate about the trending technology stacks and using them to deliver products that help businesses.
Portfolio
Experience
Availability
Preferred Environment
Data Build Tool (dbt), PostgreSQL, SQL, Python, Apache Airflow, Snowflake, Shell Scripting, Amazon Web Services (AWS), Data Pipelines, Database Administration (DBA)
The most amazing...
...projects I've worked on involved building data and DevOps pipelines on AWS, managing large databases, and writing tools for monitoring and patching.
Work Experience
Data Engineer
Wenzel Spine
- Created and maintained ETL processes and ELT data pipelines from various sources.
- Utilized Python decorators, the data build tool (DBT) app, and APIs and deployed them to the Docker host and Kubernetes.
- Developed REST APIs and deployed them using Kubernetes.
- Designed interactive and dynamic dashboards using Tableau to visualize complex data sets and KPIs effectively, enabling stakeholders to identify trends and insights quickly.
- Generated advanced Tableau dashboards with quick/context/global filters, parameters, Sets, LODs, advanced maps, and calculated fields.
Database Administrator
Ercot
- Upgraded and managed an extensive data warehouse database.
- Provided SQL tuning support to a developer during the upgrade process.
- Conducted a development and test database refresh and wrote a shell script to automate the refresh process.
- Performed periodic GI patching for over 200 databases during the patching cycle.
- Monitored databases and eliminated downtime by creating Linux and Unix shell and PL/SQL scripts.
- Planned and completed disaster recovery and switchover testing for databases.
- Used real application testing before critical database changes, including migration, upgrading, major patches, and deployment.
- Developed a database and system monitoring tool using PowerShell and Transact-SQL.
Data Engineer
Statera Spina
- Built and orchestrated data pipelines using Apache Airflow.
- Introduced DBT to the ETL system to transform data and built DBT modules.
- Developed and maintained data pipelines that were ingesting data from various sources like Amazon S3 buckets, third-party REST APIs, SQL, and NoSQL databases.
Data Engineer
Kredya
- Utilized AWS Lambda, Amazon DynamoDB, Snowflake, Amazon RDS, Amazon S3, pandas, and Python.
- Built a DevOps pipeline on AWS using GitHub, Jenkins, Ansible, Docker, and Kubernetes.
- Designed and implemented data models for a data warehouse and data marts.
- Developed, maintained, and monitored ETL processes and ELT data pipelines.
- Provided SQL tuning support for the production database.
- Migrated our data warehouse database from Postgres to the Snowflake database.
Database Administrator
TEB
- Supported and maintained over 200 Oracle databases in different environments, including production, test, development, and Oracle Active Data Guard.
- Implemented the migration of databases from Linux to Unix and vice versa.
- Cloned, refreshed, and restored Oracle databases for development and testing.
- Created multiple Linux and Unix shells and PL/SQL scripts to monitor Oracle databases and eliminate downtime proactively.
- Installed and configured integrated and classic GoldenGate for data replication.
- Configured, installed, and implemented PostgreSQL, SQL Server, and Cassandra databases.
- Set up PostgreSQL for high availability and replication with a hot standby.
- Planned and implemented Oracle and PostgreSQL backup strategies.
- Conducted various implementation tasks concerning alert monitoring for CPU usage, disk space, contention, and high events.
Data Engineer
TEB
- Wrote advanced queries, PL/SQL packages, functions, triggers, SQL scripts, and views.
- Developed ETL scripts to load data from multiple sources into the data warehouse and analyzed, cleaned, transformed, and loaded data using ODI.
- Utilized erwin for the warehouse's logical and physical database modeling.
Software Developer
Obase
- Created internal tools using Python, SQL, and Oracle.
- Analyzed, designed, and developed client applications using Oracle Forms and Report.
- Used Python to extract data from comma-separated values files, JSON, and Microsoft Excel.
Experience
Modern Data Platform and CI/CD
Next, I covered data ingestion using custom Python code, pandas that ingested some of the data from various sources, Airbyte and Fivetran for data source implementation, and Apache Airflow for data orchestration. To conduct data transformation and modeling, I used DBT and transformed data that was loaded into the warehouse.
The DevOps pipeline was built on AWS, using Ansible, Jenkins, Docker, and Kubernetes, and ran on Amazon EC2 instances. Finally, I deployed REST API on Kubernetes and Dockerized the data build tool.
Skills
Languages
SQL, Python, Bash, T-SQL (Transact-SQL), SQL DML, JavaScript, Snowflake
Frameworks
ASM, Windows PowerShell
Libraries/APIs
REST APIs, Pandas
Tools
RMAN, Git, Tableau, PyCharm, Apache Airflow, Oracle GoldenGate, Jenkins, Ansible, GitHub
Paradigms
ETL, DevOps
Platforms
Linux, Airbyte, Docker, Oracle, AWS Lambda, Amazon Web Services (AWS), Kubernetes, Amazon EC2
Storage
PostgreSQL, Database Management, PL/SQL, SQL Server DBA, Data Pipelines, Database Administration (DBA), SQL Performance, Microsoft SQL Server, Amazon S3 (AWS S3), MySQL, Relational Databases
Other
Data Build Tool (dbt), Data Warehousing, Shell Scripting, ELT, Upgrades, Data Engineering, CI/CD Pipelines, Performance Tuning, Data Queries, Data Visualization, Visualization, Software Deployment, System Design, APIs, Cloud, ETL Tools, SSH, Fivetran
Education
Bachelor's Degree in Computer Engineering
Sakarya University - Serdivan, Turkey
Certifications
Oracle Certified Professional (Cloud)
Oracle
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