Zoltán Tálas - Data Architect

Q: Where is Zoltán based?

Zoltán is based in Budapest, Hungary .

Q: What languages does Zoltán speak?

Zoltán speaks the following languages: Hungarian (Native), English (Advanced), German (Elementary) .

Q: How many years of experience does Zoltán have?

Zoltán has at least 21 years of experience. During this time, Zoltán has worked in at least 9 different roles and for 9 different companies . The average length of individual experience is 2 years and 4 months . Note that Zoltán may not have shared all experience and actually has more experience.

Q: What is Zoltán's latest experience?

Zoltán's most recent position is Data Architect at Europaeiske ERV (ERGO Group AG) .

Q: What companies has Zoltán worked for in recent years?

In recent years, Zoltán has worked for Europaeiske ERV (ERGO Group AG) , Bluebird , K&H Bank , and British Petroleum .

Q: Which industries is Zoltán most experienced in?

Zoltán is most experienced in industries like Information Technology , Banking and Finance , and Telecommunication . Zoltán also has some experience in Fashion , Energy , and Insurance .

Q: Which business areas is Zoltán most experienced in?

Zoltán is most experienced in business areas like Information Technology , Business Intelligence , and Product Development . Zoltán also has some experience in Research and Development .

Q: Which industries has Zoltán worked in recently?

Zoltán has recently worked in industries like Information Technology , Energy , and Banking and Finance .

Q: Which business areas has Zoltán worked in recently?

Zoltán has recently worked in business areas like Information Technology , Product Development , and Business Intelligence .

Recommended expert

Budapest, Hungary

Check rate

Experience

Jun 2025 - Present

1 year

Budapest, Hungary

Data Architect

Europaeiske ERV (ERGO Group AG)

Provide technical leadership within a 5-person DWH team maintaining an insurance Data Warehouse for claims, policy, finance and management reporting.
Maintain and extend dimensional models and reporting structures supporting downstream Power BI, SSRS and SSAS consumption.
Stabilise business-critical finance and IFRS reporting by resolving recurring data quality, transformation logic and SQL/SSIS processing issues.
Helped improve quarterly IFRS report quality from approximately 60% to around 98% across PRE and ACT reporting cycles.
Troubleshoot and optimise complex T-SQL stored procedures, SSIS packages and SQL Server data flows.
Technologies: SQL Server, T-SQL, SSIS, SSRS, SSAS, SSMS, Power BI

Dec 2023 - Jun 2025

1 year 7 months

Budapest, Hungary

SQL Domain Expert / AI Model Trainer

Bluebird

Applied deep SQL and database expertise to train and evaluate large language models on complex database reasoning tasks.
Designed advanced SQL training and evaluation scenarios covering correctness, optimisation, execution plans, indexing, data modelling and cross-database behaviour.
Evaluated and corrected AI-generated SQL across Oracle, PostgreSQL, SQL Server, MySQL, BigQuery, Hive and SQLite using synthetic enterprise-style datasets.
Served as reviewer and senior reviewer, ensuring task quality, evaluation consistency and high standards across SQL-focused model training workflows.
Technologies: Oracle, PostgreSQL, SQL Server, MySQL, BigQuery, Hive, SQLite

Jan 2022 - Mar 2023

1 year 3 months

Budapest, Hungary

Big Data Architect / Team Lead

K&H Bank

Technically led a 3-person team developing a near-real-time banking messaging platform for push, SMS, email, system and campaign communications.
Established code review, logging, clean code and maintainability standards across Oracle, Python and Airflow components.
Reused legacy Oracle stored procedures and Python logic while introducing Airflow-based orchestration for future cloud alignment.
Supported hybrid architecture planning, connecting on-premise Oracle/DWH capabilities with longer-term cloud platform direction.
Technologies: Oracle, PL/SQL, Python, Apache Airflow, Hadoop

Aug 2020 - Dec 2021

1 year 5 months

Budapest, Hungary

Big Data Architect

British Petroleum

Took ownership of an existing Cloudera-based data lake and reporting platform, leading 2 developers across Informatica Big Data ETL, Hive/Impala data structures and Power BI reporting support.
Supported multiple downstream reporting consumers by investigating data quality, processing and operational issues across the Cloudera/Hadoop environment.
Led technical migration of multiple legacy reporting applications to Azure using Azure Databricks and Azure Data Factory.
Designed a pragmatic migration pattern with ADF used for scheduling/orchestration and Databricks notebooks handling SQL/Python transformation logic, parallel processing and load control.
Built detailed source-to-target validation across row counts, column values and business rules to prove data consistency between legacy and migrated solutions.
Identified and corrected legacy defects during migration, delivering the new reporting solution according to plan while improving accuracy versus the original implementation.
Technologies: Cloudera, Informatica Big Data Management, Hive, Impala, Hadoop, Azure Databricks, Azure Data Factory, SQL, Python, Power BI

Aug 2018 - Jul 2020

2 years

Budapest, Hungary

Staff Data Engineer

Hortonworks / Cloudera

Created a centralised engineering reporting platform where release validation data had previously been fragmented across Jira, Git and test execution systems.
Integrated Jira issue data, Git commit history, release metadata and Elasticsearch-based test results to provide a unified view of component quality across release cycles.
Enabled development teams to analyse regressions, fixes and test outcomes, making it easier to understand which releases introduced or resolved specific issues.
Owned end-to-end database and reporting architecture, from data model and ingestion logic to Tableau/Superset dashboards and Docker/Kubernetes deployment.
Acted as the primary database and reporting specialist within an approximately 8-person internal platform team, combining architecture, development and stakeholder collaboration.
Technologies: Cloudera, Hortonworks, Hive, Impala, Spark, Hadoop, Elasticsearch, Kibana, Logstash, PostgreSQL, Tableau, Apache Superset, Docker, Kubernetes, Jira, Git, Python

Jun 2015 - Aug 2018

3 years 3 months

Budapest, Hungary

Lead Data Engineer/Data Architect

GE Digital

Served as data architect for an approximately 15-person data & analytics delivery team, shaping technical direction for DWH, data lake, reporting and analytics initiatives.
Designed enterprise DWH and analytical backend solutions primarily on Greenplum, with additional Oracle and PostgreSQL implementations.
Guided ETL/data integration delivery using Talend and Informatica, supporting enterprise reporting and Tableau consumption.
Acted as escalation point for complex SQL, data modelling and reporting performance issues across critical analytics projects.
Optimised Tableau and handheld field reporting backends, reducing key report runtimes from minutes or non-completion to under one second.
Technologies: Greenplum, Oracle, PostgreSQL, Informatica, Talend, Solr, Elasticsearch, Kibana, Logstash, Spark, Hadoop, Hive, Parquet, ORC, Python, AWS, Tableau

Mar 2013 - May 2015

2 years 3 months

Budapest, Hungary

Data Engineer

Secret Sauce Partners

Built the company’s first scalable DWH / big data platform for fashion-tech analytics products, supporting Fit Predictor, size recommendation and personalisation use cases.
Integrated multi-tenant e-commerce data across orders, returns, product/size charts, clickstream events and customer behaviour signals from multiple clothing brands.
Helped scale the architecture from PostgreSQL/Pentaho to AWS/Hadoop as major customer growth exceeded the limits of the original relational platform.
Developed batch processing pipelines using S3, EMR, Hive, Pig Latin, Parquet and Sqoop, with Redshift handling high-volume clickstream analytics of approximately 10M+ daily events.
Loaded curated analytical outputs into MongoDB to support the Fit Predictor algorithm and application consumption, and delivered BI datasets for reporting.
Technologies: AWS EMR, S3, Redshift, Hadoop, Hive, Pig Latin, Spark SQL, Avro, Parquet, Sqoop, MongoDB, PostgreSQL, Pentaho, Tableau, Superset, Snowplow

Sep 2009 - Mar 2013

3 years 7 months

Budapest, Hungary

DWH Architect

HP Hungary

Worked on Vodafone’s enterprise Oracle-based DWH, adapting dimensional models, ETL logic and Business Objects reporting structures.
Supported Siebel CRM implementation and integration into downstream DWH/reporting processes.
Guided 2 developers across PL/SQL, Oracle Warehouse Builder ETL and production support activities.
Technologies: Oracle, PL/SQL, Oracle Warehouse Builder, Business Objects

Aug 2004 - Sep 2009

5 years 2 months

Budapest, Hungary

BI/DWH Developer

Tata Consultancy Services

Delivered enterprise Data Warehouse solutions for GE Capital, implementing ETL processes and dimensional models to support reporting requirements.
Designed and developed ETL using Informatica, and created reporting structures and BI artifacts.
Provided production support, release management and stakeholder coordination to maintain data availability and quality.
Technologies: Oracle, Informatica, Business Objects, QlikView

Industry Experience

See where this freelancer has spent most of their professional time.

Experienced in Information Technology, Banking and Finance, Telecommunication, Fashion, Energy, and Insurance.

Information Technology

Banking and Finance

Telecommunication

Fashion

Energy

Insurance

Business Area Experience

See which departments and functions this freelancer has contributed to most.

Experienced in Information Technology, Business Intelligence, Product Development, and Research and Development.

Information Technology

Business Intelligence

Product Development

Research and Development

Summary

Senior Data Architect with 20+ years of experience designing and delivering enterprise DWH, data lake and analytical platforms across banking, insurance, telecom, energy and retail technology. Expert in dimensional modelling, ETL/ELT architecture, SQL performance tuning and large-scale data migration. Proven technical leader with experience mentoring teams, stabilising business-critical reporting, building greenfield data platforms and supporting cloud/big-data migrations across Azure, AWS and Cloudera-based environments.

Skills

Data Architecture | Dwh & Data Marts | Dimension Modelling | Etl / Elt Architecture | Data Integration | Data Migration | Data Quality | Sql Performance Tuning | Bi & Reporting | Data Lakes | Cloud & Big Data Platforms | Data Engineering | Technical Leadership
Data Architecture: Enterprise Dwh, Data Marts, Dimension Modelling, Star Schema, Scd, Olap, Kimball, Inmon, Row-Based Storage, Columnar Storage, Data Lake Architecture, Data Migration, Data Quality
Sql & Databases: Oracle, Sql Server, Postgresql, Greenplum, Redshift, Bigquery, Mysql, Hive, Pl/Sql, T-Sql, Sql Performance Tuning
Etl & Orchestration: Informatica, Informatica Bdm, Owb, Talend, Pentaho, Ssis, Airflow, Azure Data Factory, Azure Databricks Workflows
Bi & Reporting: Tableau, Power Bi, Business Objects, Qlikview, Superset, Kibana, Ssrs, Ssas
Nosql: Mongodb, Solr, Elasticsearch
Cloud & Big Data: Aws, Emr, S3, Redshift, Cloudera, Azure, Hadoop, Spark, Hive, Impala, Pig, Parquet, Avro
Other: Shell, Python, Git, Jira, Confluence, Agile, Scrum, Docker, Kubernetes

Languages

Hungarian

Native

English

Advanced

German

Elementary

Education

Sep 1999 - Sep 2003

International Business School (IBS)

Economic degree, specialization in BI · Economics · Budapest, Hungary

Statistics

Experience

Total positions 9

Experience in Information Technology 6.5 y

Avg length 2 y 4 m

Longest experience 5 y 1 m

Global Experience

Countries worked in 1 (Hungary)

Primary country Hungary

Expertise

Recent roles Data Architect, SQL Domain Expert / AI Model Trainer, Big Data Architect / Team Lead

Main industries Information Technology, Banking and Finance, Telecommunication

Main business areas Information Technology, Business Intelligence, Product Development

Profile

Created

May 2026

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Frequently asked questions

Have questions? Find more information here.

Where is Zoltán based?

Zoltán is based in Budapest, Hungary.

What languages does Zoltán speak?

Zoltán speaks the following languages: Hungarian (Native), English (Advanced), German (Elementary).

How many years of experience does Zoltán have?

Zoltán has at least 21 years of experience. During this time, Zoltán has worked in at least 9 different roles and for 9 different companies. The average length of individual experience is 2 years and 4 months. Note that Zoltán may not have shared all experience and actually has more experience.

What roles would Zoltán be best suited for?

Based on recent experience, Zoltán would be well-suited for roles such as: Data Architect, SQL Domain Expert / AI Model Trainer, Big Data Architect / Team Lead.

What is Zoltán's latest experience?

Zoltán's most recent position is Data Architect at Europaeiske ERV (ERGO Group AG).

What companies has Zoltán worked for in recent years?

In recent years, Zoltán has worked for Europaeiske ERV (ERGO Group AG), Bluebird, K&H Bank, and British Petroleum.

Which industries is Zoltán most experienced in?

Zoltán is most experienced in industries like Information Technology, Banking and Finance, and Telecommunication. Zoltán also has some experience in Fashion, Energy, and Insurance.

Which business areas is Zoltán most experienced in?

Zoltán is most experienced in business areas like Information Technology, Business Intelligence, and Product Development. Zoltán also has some experience in Research and Development.

Which industries has Zoltán worked in recently?

Zoltán has recently worked in industries like Information Technology, Energy, and Banking and Finance.

Which business areas has Zoltán worked in recently?

Zoltán has recently worked in business areas like Information Technology, Product Development, and Business Intelligence.

What is Zoltán's education?

Zoltán attended International Business School (IBS) for Economics.

What is the availability of Zoltán?

Zoltán will be available from June 2026.

What is the rate of Zoltán?

Zoltán's rate depends on the specific project requirements. Please use the Meet button on the profile to schedule a meeting and discuss the details.