Vitalii Paderin - Senior Full Stack Engineer

Q: Where is Vitalii based?

Vitalii is based in Warsaw, Poland and can operate in on-site , hybrid , and remote work models.

Q: What languages does Vitalii speak?

Vitalii speaks the following languages: English (Advanced), German (Intermediate) .

Q: How many years of experience does Vitalii have?

Vitalii has at least 9 years of experience. During this time, Vitalii has worked in at least 3 different roles and for 3 different companies . The average length of individual experience is 3 years and 10 months . Note that Vitalii may not have shared all experience and actually has more experience.

Q: What is Vitalii's latest experience?

Vitalii's most recent position is Senior Full Stack Engineer at Ada Health .

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

In recent years, Vitalii has worked for Ada Health .

Q: Which industries is Vitalii most experienced in?

Vitalii is most experienced in industries like Healthcare , Information Technology , and Retail . Vitalii also has some experience in Banking and Finance .

Q: Which business areas is Vitalii most experienced in?

Vitalii is most experienced in business areas like Information Technology and Product Development .

Q: Which industries has Vitalii worked in recently?

Vitalii has recently worked in industries like Healthcare .

Q: Which business areas has Vitalii worked in recently?

Vitalii has recently worked in business areas like Information Technology and Product Development .

Recommended expert

Warsaw, Poland

Experience

Jan 2021 - May 2025

4 years 5 months

Berlin, Germany

Senior Full Stack Engineer

Ada Health

Spearheaded an AI-powered patient-facing healthcare management system using Python, Java 17, Spring Boot, Angular and Hibernate, reducing patient registration time by 40% through streamlined workflows.
Migrated legacy monolithic EMR application to a microservices architecture, enhancing system scalability and reducing deployment time by 60%.
Integrated Python FastAPI microservices with the healthcare platform to serve real-time predictive analytics, ensuring sub-second response times for clinical dashboards.
Implemented secure RESTful APIs with Spring Security, JWT, and OAuth 2.0, ensuring HIPAA compliance and improving access control auditing by 100%.
Integrated with FHIR and HL7 standards using HAPI-FHIR and Mirth Connect to enable seamless data exchange with third-party EHR systems, covering 90%+ interoperability use cases.
Leveraged Apache Kafka for real-time lab result processing and notifications, achieving 3× faster delivery of critical patient updates to physicians.
Engineered a conversational mental health assistant powered by Python NLP pipelines and OpenAI API, handling 10,000+ weekly queries and deflecting 35% of routine support requests.
Built custom medication tracking modules with barcode integration, developing smart alerting algorithms and patient-facing mobile interfaces that increased medication adherence monitoring by 35%.
Optimized complex SQL and JPQL queries in PostgreSQL, reducing report generation latency by 45% through indexing and query tuning.
Engineered role-based access control (RBAC) with Spring Security and LDAP integration, ensuring secure multi-role access across administrative and clinical users.
Utilized Jenkins, Docker, and Kubernetes to automate CI/CD pipelines and streamline deployment to on-prem and cloud environments, improving deployment reliability by 70%.
Created interactive, real-time dashboards with React and D3.js for clinicians to monitor patient vitals and analytics, contributing to a 25% improvement in decision-making speed.
Applied Test-Driven Development (TDD) using JUnit, Mockito, and TestContainers, increasing test coverage to 85% and reducing post-release bugs by 50%.
Integrated Python ML models into the React frontend via REST APIs, enabling instant feedback loops for exercises like mood tracking and journaling.
Participated in Agile ceremonies (sprint planning, retrospectives, daily standups) and led backlog refinement sessions, contributing to consistent 95%+ sprint delivery rate.
Collaborated in Agile teams, conducted code reviews, and mentored junior engineers, contributing to a 25% increase in team velocity and overall code quality.

Jun 2018 - Oct 2020

2 years 5 months

London, United Kingdom

Java Software Developer

Xeven Solutions

Launched scalable backend systems for a high-traffic eCommerce platform using Java, Spring Boot, and MySQL, supporting over 80,000+ monthly active users.
Generated microservices architecture to handle catalog, inventory, and order processing services, improving deployment flexibility and reducing service downtime by 70%.
Achieved a mobile-first, responsive shopping interface using React.js, TypeScript, and Material-UI, integrated with FastAPI REST endpoints, increasing session duration and user engagement by 25%.
Composed Apache Kafka for real-time order events, reducing cart abandonment and improving transaction traceability by 40% through asynchronous messaging and retry strategies.
Combined secure RESTful APIs for checkout, payment, and order tracking with Spring Security, implementing JWT authentication and OAuth 2.0, reducing fraud incidents by 30%.
Revised product search and filtering using Elasticsearch, improving search response time by 50% and increasing user engagement metrics across mobile and web.
Organized Redis-based caching for product details and user sessions, reducing backend load by 60% during peak traffic events like Black Friday and flash sales.
Revised containerized services using Docker and Kubernetes on AWS EKS, with auto-scaling and failover, ensuring 99.99% uptime during high-demand periods.
Automated CI/CD pipelines with GitHub Actions and AWS CodePipeline, enabling faster releases and reducing manual deployment errors by 80%.
Enhanced system observability with Prometheus, Grafana, and ELK stack across 3 microservices, enabling real-time monitoring of container resource utilization and reducing average issue detection time by 45%.
Achieved the development of real-time admin dashboards with React, TypeScript, and Chart.js, visualizing sales trends, inventory movement, and user behavior in real time.
Established a responsive React Native mobile app for shopping, order tracking, and notifications, boosting mobile conversion rate by 35%.

Apr 2016 - Feb 2018

1 year 11 months

Warsaw, Poland

Software Developer

Scalo

Developed Java-based SaaS, CRM, and fintech systems for agency projects, improving system performance for 10,000+ daily active users and ensuring seamless customer experience through optimized backend services.
Introduced a micro-payment gateway using Spring Boot, Spring Security, OAuth2, and JWT authentication, reducing transaction failures by 25% and improving payment reliability.
Designed and implemented batch-processing jobs using Spring Batch and Quartz Scheduler, automating financial data processing and cutting manual workload by 50%, improving operational efficiency.
Redesigned SQL queries and Hibernate configurations in PostgreSQL, reducing query response times by 20% and enhancing database performance.
Reduced music search response times from 1.8 seconds to 0.5 seconds (a 3.4× improvement) by leveraging Elasticsearch for advanced indexing strategies, improving user search experience.
Developed RESTful APIs using Spring MVC and GraphQL with Apollo Server, enhancing data-fetching efficiency and improving frontend-backend communication for dynamic user interfaces.
Integrated third-party payment APIs (Stripe, PayPal, Plaid) into systems, streamlining transaction workflows and enhancing user payment experience with seamless integrations.
Built real-time event-driven microservices using Apache Kafka and WebSockets, improving system responsiveness and reliability during peak usage periods.
Integrated Micrometer with Spring Boot Actuator to expose real-time metrics for Prometheus, improving system observability and proactive issue resolution across microservices.
Automated CI/CD pipelines using Jenkins and Docker, improving deployment speed and system stability across multiple environments, ensuring a consistent delivery process.

Industry Experience

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

Experienced in Healthcare, Information Technology, Retail, and Banking and Finance.

Healthcare

Information Technology

Retail

Banking and Finance

Business Area Experience

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

Experienced in Information Technology and Product Development.

Information Technology

Product Development

Summary

Java Software Engineer with over 10 years of experience designing and enhancing enterprise-level solutions. I thrive on solving complex challenges and delivering results-driven software. My expertise includes Java, Spring Boot, Java EE, Python, SQL, React, Angular, AWS, Kubernetes, Kafka, and AI integration.

Skills

Languages: Java, Python, Javascript, Go
Backend: Spring Boot, Spring Cloud, Java Ee, Quarkus, Fastapi, Django, Rest, Graphql, Grpc, Kafka, Rabbitmq, Redis, Ehcache, Micronaut, Openapi, Swagger, Junit, Testng, Spring Boot Test
Frontend: React.js, Next.js, Angular, Vue.js, Tailwind Css, Material Ui, React Native, Flutter, Kotlin, Swift, Chart.js, Redux, Redux Toolkit, Zustand
Testing: Junit 5, Testng, Spring Test, Restassured, Selenium, Jest, Postman
Databases: Mysql, Postgresql, Mongodb, Aws Dynamodb, Azure Cosmos Db, Jpa, Hibernate, Liquibase
Cloud & Devops: Aws (Ecs, Lambda, Sqs, Sns, S3, Rds, Api Gateway), Gcp, Kubernetes (Eks/gke), Docker, Helm, Terraform, Github Actions, Jenkins, Elk, Prometheus, Grafana
Monitoring & Logging: Cloudwatch, Elk Stack, Opentelemetry, Jaeger, Grafana, Distributed Tracing
Architecture & Patterns: Microservices, Event-driven Systems, Serverless, Cqrs, Ddd, Mdsd, Soa, Dsl, Monolith-to-microservice Migration, Mvvm, Dependency Injection (Di), Ssr, Mvc
Compliance & Protocols: Fhir, Hl7, Hipaa, Pci-dss, Websockets, Tcp/ip, Rest, Soap
Security: Oauth2, Jwt, Keycloak, Openid Connect, Saml, Ssl/tls, Rbac, Mfa, Azure Key Vault, Aws Kms
Ai/ml: Openai Api, Hugging Face Transformers, Tensorflow, Nlp, Pandas, Numpy, Shap, Mlflow
Tools & Workflow: Agile (Scrum, Kanban), Jira, Confluence, Bitbucket, Git, Intellij, Vs Code

Languages

English

Advanced

German

Intermediate

Education

Mar 2012 - Nov 2015

University of Warsaw

Bachelor of Science, Computer Science · Computer Science · Warsaw, Poland

Statistics

Experience

Total positions 3

Experience in Healthcare 4.5 y

Avg length 2 y 10 m

Longest experience 4 y 4 m

Global Experience

Countries worked in 3 (Germany, United Kingdom, Poland)

Primary country Germany

Expertise

Recent roles Senior Full Stack Engineer, Java Software Developer, Software Developer

Main industries Healthcare, Information Technology, Retail

Main business areas Information Technology, Product Development

Qualifications

Highest degree Bachelor

Profile

Created

December 2025

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Frequently asked questions

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

Where is Vitalii based?

Vitalii is based in Warsaw, Poland and can operate in on-site, hybrid, and remote work models.

What languages does Vitalii speak?

Vitalii speaks the following languages: English (Advanced), German (Intermediate).

How many years of experience does Vitalii have?

Vitalii has at least 9 years of experience. During this time, Vitalii has worked in at least 3 different roles and for 3 different companies. The average length of individual experience is 3 years and 10 months. Note that Vitalii may not have shared all experience and actually has more experience.

What roles would Vitalii be best suited for?

Based on recent experience, Vitalii would be well-suited for roles such as: Senior Full Stack Engineer, Java Software Developer, Software Developer.

What is Vitalii's latest experience?

Vitalii's most recent position is Senior Full Stack Engineer at Ada Health.

What companies has Vitalii worked for in recent years?

In recent years, Vitalii has worked for Ada Health.

Which industries is Vitalii most experienced in?

Vitalii is most experienced in industries like Healthcare, Information Technology, and Retail. Vitalii also has some experience in Banking and Finance.

Which business areas is Vitalii most experienced in?

Vitalii is most experienced in business areas like Information Technology and Product Development.

Which industries has Vitalii worked in recently?

Vitalii has recently worked in industries like Healthcare.

Which business areas has Vitalii worked in recently?

Vitalii has recently worked in business areas like Information Technology and Product Development.

What is Vitalii's education?

Vitalii holds a Bachelor in Computer Science from University of Warsaw.

What is the availability of Vitalii?

Vitalii is immediately available full-time for suitable projects.

What is the rate of Vitalii?

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