Konstantinos Servis

• Conducted data release for COSMOS Web and COSMOS Spectroscopic Redshift Compilation, which is focused on the most distant known galaxies from JWST data. • Reengineered the GAZPAR backend system using FastAPI/Python, enhancing galaxy redshift determination processes. • Collaborated with a multidisciplinary team at Laboratoire d'Astrophysique de Marseille, contributing to cutting-edge astrophysical research.

• Guided experienced professionals in transitioning to Data Engineering through hands-on projects and theoretical knowledge. • Developed comprehensive case studies focusing on technologies such as Hadoop, Hive, and Spark. • Collaborated with a dynamic team at Code.Hub, a startup dedicated to empowering tech talent in Greece.

• Developed and maintained scalable data pipelines for Snowplow analytics, utilizing Scala. • Contributed to both open-source and internal projects, enhancing analytics capabilities for clients. • Collaborated with cross-functional teams to optimize data processing on AWS and GCP.

Working principally on the passport analytics module which is a self-service analytics module for the main SaaS product of the company. Responsible for ingestion/ETL and monitoring. Technologies used include Spark, Scala, Python, Kinesis, Lambda, SQS and EMR.

Worked on a number of projects for team Omnia, principally on the transactional data pipeline using scala, scalding, map reduce and hive. Introduced driven to the team to help increase performance and cut down costs. Started a number of initiatives to drive down cost and increase efficiency such as using better compression in HDFS, improving release process and version control of release.

Developed AWS infrastructure pilot of the Analytics and Search capabilities of the company. This involved CloudFormation, Kinesis, SQS, Lambda, Data Pipeline, S3, OpsWorks.

Setup the AWS subaccount for the growth department, including VPC, DNS using Ansible and CloudFormation, cutting down provisioning time of production and demonstration systems from days and even weeks to minutes. Setup the real-time analytics pipeline using Kafka, Storm, Influxdb and Grafana, enabling real-time view of user behaviour for experiment analysis, abuse detection and behaviour triggered communications. Improved the reliability and stability of the batch ETL and improving the time data was available in the Hive and Redshift data warehouse, using AWS data pipeline, SQS, ECS, Docker, Scala and Akka and Avro. Introduced integration testing for the analytics events relay service, and improved unit test coverage using Docker and JUnit. Improved early detection of data product inconsistencies, by introducing data product quality testing, using Scala, SBT and Bamboo.

Developing the analytics infrastructure and general back-end services and conducting ad-hoc analysis.

Back end development, supporting the analytics department in reaching their short and long term objectives by developing batch and real time big data infrastructure and applications. Specifically, developed the Event Tracking system of InnoGames using to a greater or lesser degree: Twitter Kestrel, Twitter Storm, Hadoop MapReduce, Hive, Pig, Dropwizard, Sinatra, MongoDB, Akka and d3.js. Additionally worked in providing data to the BI system, and in ad hoc analysis. Languages used mostly were Scala, Java, Ruby and Perl.

Web services developer in the healthcare industry, using JRuby, Sinatra and Chef.

Research assistant with the program analysis team at Oracle Labs.

Mostly web-development on LAMP(erl) and networking. Software types: domain specific (internet governance) resource administration system, event management and support systems.

Software development, mainly C and Java. Application domain: healthcare administration. Software types: low-level DB development, networking, UI.

Maintenance and development of database applications and reporting.