Recommended expert

Serge (Dr.) Kalinin

MLOps (machine learning operations)

Serge Kalinin
Munich, Germany

Experience

Apr 2025 - Present
11 months
Cologne, Germany

MLOps (machine learning operations)

REWE Digital GmbH

  • It is like a startup within REWE, where we have to build a new forecasting system on Google Cloud Platform from the scratch. Although, officially my role is called MLOps, my actual tasks also include development of data processing pipelines (data engineering) and data scientists tasks such as feature engineering and model trainings.
  • GCP: Terraform (tofu), Vertex AI (Kubeflow), Cloud Run, IAM, Google Cloud Storage, BigQuery, Artifact Registry
  • Data engineering: Snowflake as the main data warehouse, Terraform, DBT for data model implementations
  • CI/CD: GitLab. We have built a CI/CD pipeline that automates deployments of new releases up to production environment
Jan 2025 - Apr 2025
4 months
United States

Senior Software Developer (freelancer)

StarStruck

  • Consolidate visibility of companies or software products in marketplaces to compare footprints.
  • Develop data models and troubleshoot scraper scripts.
  • Assign development tasks to other developers.
  • Text analysis and implementation of recommendation system.
  • AWS: DynamoDB, Lambda, S3, EC2, IAM, EventBridge.
  • Scraping: Python, Selenium Chrome Webdriver.
  • Text analysis: Amazon Comprehend.
  • Recommendation system: XGBoost.
  • MLOps: MLFlow
Apr 2022 - Dec 2024
2 years 9 months
Karlsruhe, Germany

Senior Software Developer (extern)

Atrvivia AG (via STI GmbH, Michael Page International)

  • Developed Data Integration Hub platform (DIH) for a Data Governance project, central architecture for sharing data between tenants, based on data product descriptions, data catalogs and services representing Data Mesh and Data Vault 2.0.
  • Workflow: inject data product description via REST API or Swagger UI; metadata written into Kafka topics; Kafka consumers create metadata in Datahub, tables in Trino, file structures on S3, policies, etc.
  • Implemented single sign-on in services based on JWT tokens.
  • Developed REST APIs and integration tools between SelfService, Trino, S3, Datahub, Great Expectations.
  • Performed data synchronization between S3 and Azure Blob Storage.
  • Developed ETL with PySpark on Azure Databricks and pipelines with pandas, PySpark, Airflow DAGs.
  • Built data quality validation services and monitoring systems.
  • Created accounting system based on CPU, storage and memory usage using star schema.
  • Developed complex data models (up to 5000 columns from several hundreds data sources).
  • Troubleshot and supported services and customers; delivered according to AGILE/SCRUM.
  • CI/CD: OpenShift (Kubernetes), Helm, Docker, Git, Tekton, ArgoCD, Terraform.
  • Data catalogs and lineage: Datahub, OpenLineage; Python.
  • SQL engines: Trino with Starburst Web UI, PostgreSQL, Hive, DB2, Delta Lake.
  • Data quality: Great Expectations, Talend.
  • Code quality: SonarQube.
  • REST API: Java, Swagger UI, Spring Boot.
  • Authentication: JWT, OAuth2, Single Sign-On; Apache Ranger; Prometheus and Grafana
Oct 2021 - Apr 2023
1 year 7 months
Hamburg, Germany

Senior Software Developer (extern)

Otto GmbH & Co KG (via Soorce GmbH)

  • Designed and implemented data-driven microservices for search engine optimization using AWS services; ETL patterns: ingest data from REST API, SQS, DynamoDB; transform; upload to S3 or database.
  • Service I (MLOps): assessed OTTO pages by extracting keywords and matching with Google searches; migrated data transformation, model training/retraining, and deployment from GCP to AWS; designed workflows.
  • Used GitHub Actions for CI/CD and Terraform for cloud resource management.
  • Implemented model validations and testing with Python; model monitoring with Grafana.
  • Service S: handled millions of REST API calls per hour using AsyncIO; parsed nested JSON; stored results on S3.
  • Languages: Python, Java, TypeScript, Kotlin.
  • Monitoring: CloudWatch, Grafana, Tableau.
  • Databases: MongoDB, DynamoDB, PostgreSQL, Exasol.
  • Message processing: SNS, SQS.
  • Provisioning: Terraform, Pulumi, Serverless (Cloud Foundation).
  • Containers: Docker, ECR, ECS.
  • Unit tests: PyTest; delivery according to AGILE/SCRUM
Jul 2018 - Sep 2021
3 years 3 months
Cologne, Germany
Hybrid

Senior Big Data Consultant (extern)

REWE Systems GmbH (via STI GmbH)

  • Conceptualized and implemented hybrid environments on Google Cloud Platform.
  • Developed and optimized normalized data models and Spark ETL workflows using dbt.
  • Created data warehouse models on Hadoop using Data Vault 2.0.
  • Provisioned MapR and Spark (Databricks) environments on GCP with Terraform; set up real-time data replication from on-premise to GCP.
  • Integrated with REWE services (Active Directory, DNS, Instana).
  • Developed REST API for ML models using Flask.
  • Implemented persistent storage based on MapR for Kubernetes cluster.
  • Operated MapR clusters: upgrades, extensions, troubleshooting via Ansible and Jenkins.
  • Synchronized Kafka cluster with MapR streams using Kafka Connect.
  • Designed ETL pipelines, synchronization and integration of MapR with DB2 and Teradata.
  • Onboarded new internal customers; consulted management on Big Data topics; proposed security solutions and PoCs.
  • Developed market classification models; visualized data with Jupyter and Grafana; integrated with JIRA; delivered according to AGILE/SCRUM
Sep 2016 - May 2018
1 year 9 months
Munich, Germany

Senior Big Data Architect

Allianz Technology SE

  • Managed large-scale, multi-tenant, secure, highly available Hadoop infrastructure; provided architectural guidance, capacity planning, roadmaps for deployments.
  • Conducted pre-sales onboarding; worked with infrastructure, network, database, BI and data science teams.
  • Designed, implemented and maintained enterprise-level security for Hadoop (Kerberos, LDAP/AD, Sentry, encryption in motion and at rest).
  • Installed and configured multi-tenant Hadoop environments; managed updates, patches, upgrades; created run books for troubleshooting and maintenance.
  • Provided 3rd-level DevOps support; evaluated new tools and technologies.
  • Set up Microsoft R Open data science model training platform on Azure and on-premise using Docker and Terraform for fraud detection.
  • Developed Supply Chain Analytics GraphServer for HDFS graph queries.
  • Transformed internal processes to Agile/SCRUM.
  • Developed Kafka-based use cases: ClickStream (Java, Kafka, Flink, Cassandra), document classification (Java, Kafka, Spark Streaming, UIMA, Impala), graph database PoC (Java, Python, Kafka, Cassandra, Gremlin, KeyLines)
Jun 2014 - Jul 2016
2 years 2 months
Berlin, Germany

System Architect

WebThe unbelievable Machine Operations Company GmbH

Sep 2012 - Jun 2014
1 year 10 months
Cologne, Germany

System Operations

Werkenntwen GmbH

Jan 2009 - Sep 2012
3 years 9 months
Wuppertal, Germany

Postdoc

Bergische Universität Wuppertal

Oct 2006 - Dec 2008
2 years 3 months
Aachen, Germany

Postdoc

Rheinisch-Westfälische Technische Hochschule Aachen

Industries Experience

See where this freelancer has spent most of their professional time. Longer bars indicate deeper hands-on experience, while shorter ones reflect targeted or project-based work.

Experienced in Information Technology (11.5 years), Education (6 years), Retail (5.5 years), Media and Entertainment (2 years), and Insurance (1.5 years).

Information Technology
Education
Retail
Media and Entertainment
Insurance

Business Areas Experience

The graph below provides a cumulative view of the freelancer's experience across multiple business areas, calculated from completed and active engagements. It highlights the areas where the freelancer has most frequently contributed to planning, execution, and delivery of business outcomes.

Experienced in Information Technology (13 years), Business Intelligence (8.5 years), Research and Development (6 years), Product Development (5 years), and Operations (3.5 years).

Information Technology
Business Intelligence
Research and Development
Product Development
Operations

Skills

  • It: Object Oriented Programming, Databases, Administration, Distributed Computing, High Performance Computing, High Availability
  • Profound Knowledge Of Public Clouds: Aws, Microsoft Azure, Google Cloud Platform
  • Infrastructure As Code: Terraform, Ansible, Puppet
  • Expert In Hadoop Stacks: Hortonworks, Mapr, Cloudera, Spark, Kafka, Flume, Storm, Oozie, Sentry, Ranger, Knox, Hbase, Sqoop, Yarn, Mesos, Impala, Hive, Zookeeper, Key Trustee
  • Expert In Network Devices: Loadbalancer (F5, A10), Switches (Arista, Juniper, Force10), Firewalls (Juniper, Fortigate, Palo Alto), Routers (Brocade)
  • Programming Languagues: Python, Java, Sql, Scala, C++, Php, Vba, R, Ruby
  • Expert In Application Level Security Systems: Web Application Firewall, Xml-gateway, Haproxy
  • Expert In Databases: Mysql, Postgresql, Objectivity, Oracle, Microsoft Sql Server
  • Expert In Linux. Very Good Knowledge Of Microsoft Windows
  • Expert In Mass-storage Systems: Emc Isilon, Scality, Lustre/sfs, Pnfs, Hadoop, Dcache, Netapp
  • Expert In Virtualization And Containerization: Kvm, Xen, Vmware, Virtualbox, Vagrant, Docker, Cloudfoundry, Kubernetes, Citrix
  • Scms: Git, Svn, Nexus, Cvs
  • Expert In Monitoring: Grafana, Prometheus, Nagios, Cacti, Ganglia, Munin, Lemon
  • Expert In Statistics: Monte Carlo, Statistical Tests, Parameter Estimation, Error Estimation, Classification, Prediction, Unfolding, Fitting
  • Expert In Technical Analyses
  • Expert In Multi-variate Methods: Neural Networks, Support Vector Machines, Genetic Algorithms, Gradient Boosting
  • Good Knowledge Of Security Standards Such As Pci Dss
  • Ldap Authentication Systems: Activedirectory, Openldap, Apacheds

Languages

Russian
Native
German
Advanced
English
Advanced
French
Advanced

Education

Jan 2001 - Sep 2006

Université catholique de Louvain-la-Neuve

PhD Student · Ottignies-Louvain-la-Neuve, Belgium

Sep 1998 - Jun 2000

Moscow Institute of Physics and Technology

M.S., High energy physics · High energy physics · Dolgoprudny, Russian Federation

Sep 1994 - Jun 1998

Moscow Institute of Physics and Technology

B.S., High energy physics · High energy physics · Dolgoprudny, Russian Federation

Certifications & licenses

AWS Certified Data Engineer - Associate

Profile

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Frequently asked questions

Do you have questions? Here you can find further information.

Where is Serge based?

Serge is based in Munich, Germany and prefers 100% remote projects.

What languages does Serge speak?

Serge speaks the following languages: Russian (Native), German (Advanced), English (Advanced), French (Advanced).

How many years of experience does Serge have?

Serge has at least 19 years of experience. During this time, Serge has worked in at least 8 different roles and for 10 different companies. The average length of individual experience is 2 years and 11 months. Note that Serge may not have shared all experience and actually has more experience.

What roles would Serge be best suited for?

Based on recent experience, Serge would be well-suited for roles such as: MLOps (machine learning operations), Senior Software Developer (freelancer), Senior Software Developer (extern).

What is Serge's latest experience?

Serge's most recent position is MLOps (machine learning operations) at REWE Digital GmbH.

What companies has Serge worked for in recent years?

In recent years, Serge has worked for REWE Digital GmbH, StarStruck, Atrvivia AG (via STI GmbH, Michael Page International), Otto GmbH & Co KG (via Soorce GmbH), and REWE Systems GmbH (via STI GmbH).

Which industries is Serge most experienced in?

Serge is most experienced in industries like Information Technology (IT), Education, and Retail. Serge also has some experience in Media, Entertainment and Publishing and Insurance.

Which business areas is Serge most experienced in?

Serge is most experienced in business areas like Information Technology (IT), Business Intelligence, and Research and Development (R&D). Serge also has some experience in Product Development and Operations.

Which industries has Serge worked in recently?

Serge has recently worked in industries like Information Technology (IT) and Retail.

Which business areas has Serge worked in recently?

Serge has recently worked in business areas like Information Technology (IT), Business Intelligence, and Product Development.

What is Serge's education?

Serge holds a Doctorate from Université catholique de Louvain-la-Neuve, a Master in High energy physics from Moscow Institute of Physics and Technology and a Bachelor in High energy physics from Moscow Institute of Physics and Technology.

Does Serge have any certificates?

Serge has 1 certificate: AWS Certified Data Engineer - Associate.

What is the availability of Serge?

Serge is immediately available full-time for suitable projects.

What is the rate of Serge?

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

How to hire Serge?

To hire Serge, click the Meet button on the profile to request a meeting and discuss your project needs.

Average rates for similar positions

Rates are based on recent contracts and do not include FRATCH margin.

1200
900
600
300
Market avg: 940-1100 €
The rates shown represent the typical market range for freelancers in this position based on recent contracts on our platform.
Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.