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Sergiy G., Lead Java/Scala Software Engineer
Sergiy G.
🇪🇸Spain (UTC+01:00)
Created AtUpstaffer since May, 2025

Sergiy G. — Lead Java/Scala Software Engineer

Expertise in Data Engineer, Back-End Web.

Last verified on July, 2025

Bio Summary

- 12 years of experience in backend development, including leadership roles in cross-functional teams; - Expertise in Scala, Python, and Java (with knowledge of functional programming principles); - Experience in system architecture improvements, leading teams, and developing scalable solutions; - Expertise in PostgreSQL, Oracle DB, MongoDB, and SQL; - Cloud environments such as AWS including performance and scalability optimization; - Docker and Kubernetes for container orchestration; - Apache Kafka for building event-driven architectures; - Led AI-driven projects in areas such as resume parsing, payroll automation, and learning management;

Technical Skills

Programming LanguagesJava, Python, Scala
AI & Machine LearningAI
Scala FrameworksAkka, Apache Spark
Scala Libraries and ToolsAkka, Apache Flink, Scala SBT, Scala Tapir, Scalatest
Java FrameworksApache Spark, Hibernate, Spring, Spring Boot
.NET PlatformAzure
JavaScript FrameworksReact
Data Analysis and Visualization TechnologiesApache Spark
Databases & Management Systems / ORMApache Spark, Cassandra, Clickhouse, Hibernate, MongoDB, MySQL, Oracle Database, PostGIS, PostgreSQL, Redis, RocksDB, Slick database query, SQL
Cloud Platforms, Services & ComputingAWS, Azure, GCP
Amazon Web ServicesAmazon RDS, AWS S3, AWS SQS
Google Cloud PlatformGCE
Methodologies, Paradigms and PatternsAgile, microservices, REST, Scrum
Message/Queue/Task BrokersApache ActiveMQ, Kafka
QA, Test Automation, SecurityApache Maven, JUnit, Scalatest
Web/App Servers, MiddlewareApache Tomcat
Virtualization, Containers and OrchestrationDocker, GCE, Kubernetes
SDK / API and IntegrationsFacebook Auth
Deployment, CI/CD & AdministrationGitLab CI, Gradle, Helm, Jenkins
Logging and MonitoringGrafana, Prometheus, Splunk
Project Management & AdministrationRelease Management
Other Technical SkillsData pipeline design

Work Experience

Software Engineering Manager, NDA

Duration:May 2024 - Present

Summary:Cloud-based HCM platform for mid-sized businesses with integrated HR, payroll, and talent management, supporting complex payroll and third-party integrations.

Responsibilities:

  • Managed 3 cross-functional development teams, each consisting of Scala backend, JS frontend, Flutter mobile, and QAs. Handled backlog grooming, sprint planning, and release tracking;
  • Managed and prioritized 241 tasks: 66 Roadmap features, 95 Customer Feature Requests, 32 Implementation Sales Blockers, 48 Technical Debts, 10 Maintenance Updates;
  • Developed a 12-month feature roadmap, ensured alignment with quarterly releases;
  • Authored 120+ specifications, covering both business requirements and technical solutions;
  • Led AI adoption in 5 key areas - Resume Parsing, Company Policy Generation, Payroll Analyzer, Offer Letter Automation, Personalized Learning Plans;
  • Standardized specification approval workflow, reduced rework, and improved delivery throughput;
  • Facilitated cross-functional alignment with the VP of Professional Services, VP of Client Success, and CEO.

Lead Software Engineer, HERE Technologies

Duration: October 2020 - May 2024

Summary: HERE Technologies provides mapping and location data services, offering tools for custom maps, analytics, and real-time data across industries like automotive and logistics.

Responsibilities:

  • Spearheaded the development of the Flink pipeline, reducing map feature processing time by 40%;
  • Improved map accuracy leading a cross-functional collaboration with the Computer Vision team;
  • Eliminated 37% redundancy in map features, improving operational efficiency;
  • Mentored and led a team of 8 engineers, increased productivity by 25%, reduced bugs by 30%;
  • Expanded team hiring strategy, increasing diversity and technical expertise;
  • Implemented a performance management system, aligning personal development with company goals, and improving team reliability by 30%.

Technologies: Java, Scala, ScalaTest, Python, Flink, Kafka, Akka, Amazon RDS, PostgreSQL, SQL, AWS, Docker, Kubernetes, Helm, Splunk, Prometheus, Grafana, GitLab CI/CD, ClickHouse.

Lead Software Engineer, OTP Bank

Duration: December 2019 - October 2020

Summary: OTP Bank is Hungary's largest commercial bank and a leading financial services provider in Central and Eastern Europe, offering a wide range of services including retail banking, corporate banking, insurance, and asset management across multiple countries.

Responsibilities:

  • Built an advanced banking service that integrated seamlessly with the core banking system, improving reliability by 70%;
  • Developed a data unification system managing information from 10,000+ banking branches, ATMs;
  • Led a team mentorship initiative, improving skills by 40% and accelerating one engineer’s promotion to Senior in just six months;
  • Enhanced user experience, increasing customer satisfaction by 50%.

Technologies: Scala, ScalaTest, Azure, Tapir, Akka, Slick, PostGIS, MongoDB, SQL, sbt, Docker, Kubernetes.

Senior Software Engineer, Energy Trading Platform Development

Duration: September 2018 - December 2019

Summary: General Electric is a multinational conglomerate that operates in sectors such as energy, aviation, and healthcare.

Responsibilities:

  • Developed an energy trading platform, improving efficiency by 40% and serving 50,000+ users;
  • Created an AI-powered electricity consumption forecasting algorithm, achieving 80% accuracy;
  • Accelerated dispute resolution processes by 50%, optimizing energy trade workflows;
  • Led migration of 20,000+ business users to a new trading platform, increasing satisfaction by 35%;
  • Implemented React JS enhancements by updating models and updating views.

Technologies: Java, Spring, Hibernate, PostgreSQL, SQL, Amazon S3, Maven, React JS.

Software Engineer, Raiffeisen Bank International AG

Duration: August 2017 - September 2018

Summary: Raiffeisen Bank International AG is an Austrian banking group providing corporate, retail, and investment banking services across Central and Eastern Europe.

Responsibilities:

  • Integrated data from 50+ banking services, increasing financial insight accuracy;
  • Developed an algorithm processing 2M+ daily metrics, improving data reporting by 40%;
  • Increased the bank’s reporting efficiency by 50%, leading to a 25% increase in client engagement.

Technologies: Java, Spring, Hibernate, React JS, Tomcat, Oracle DB, SQL, Gradle, JUnit.

Software Engineer, NDA

Duration: October 2013 - July 2017

Summary: Development of applications for health care and websites.

Responsibilities: Developing healthcare applications and websites.

Technologies: Java, Spring Boot, REST, Hibernate, MySQL, SQL, Maven, JUnit, React JS.

Education

National University, Faculty of Economics and Management, Educational program: Economics and Business Analytics

Master of Business Administration (MBA)

Polytechnic Institute, Faculty of Informatics and Computer Science, Department of Computer-Aided Management and Data Processing Systems

Bachelor of Software Engineering

Certification

  • AWS Certified Solution Architect(Apr 2023);
  • Transition Technical Contributor to Manager;
  • From Engineer to Technical Manager(Dec 2023);
  • Mastering the System Design(May 2022);
  • Apache Flink: Real-Time Processing(Apr 2022);
  • Apache Airflow: Hands-On Guide(Jun 2023);
  • Apache Spark with Scala(Jul 2022);
  • Java Microservices: CQRS(Jun 2022).

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Sergiy G., Lead Java/Scala Software Engineer
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