Patrick S.

Senior Software Engineer

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Halle (Saale), Germany

Experience

May 2021 - Sep 2025
4 years 5 months
Berlin, Germany

Senior Software Engineer

Delivery Hero

  • Led a team of 6 software engineers to develop and maintain an AI-driven healthcare platform, enabling automated diagnostics and prescriptions based on real-time ECG data analysis
  • Designed and developed a robust Revenue Cycle Management (RCM) system, integrating HL7 and FHIR APIs to enable seamless interoperability, real-time data exchange, and HIPAA-compliant data handling, improving billing efficiency, claim processing, and regulatory adherence in healthcare operations
  • Migrated a legacy monolithic application to a scalable microservices architecture, enhancing system modularity, scalability and maintainability while implementing key design patterns such as Strangler, Database-per-Service, API Gateway, Saga and CQRS for efficient service communication and transaction management
  • Architected and led a C# 9/.NET 6 microservices ecosystem handling hotel reservations, payments, and loyalty programs, enabling 99.99% uptime across 10+ services
  • Defined OpenAPI/Swagger contracts and auto-generated client SDKs, reducing front-to-backend integration time by 50%
  • Containerized each service with Docker and orchestrated deployments via Kubernetes, slashing release lead time from days to hours
  • Designed PostgreSQL schemas optimized for high-volume transactional workloads and implemented Redis caching layers to accelerate read-heavy endpoints by 80%
  • Built Kafka streaming pipelines for real-time availability updates and audit logs, processing 2 million+ events per hour with end-to-end delivery guarantees
  • Implemented unit and integration tests for React applications using Jest and React Testing Library, ensuring 80%+ test coverage, improving component reliability, and preventing regressions
  • Defined and deployed AWS cloud infrastructure using Terraform, while containerizing and orchestrating microservices with Docker and Kubernetes, improving automation and system scalability
  • Built a scalable full-stack booking application using React 18 and Django REST Framework, integrating Celery and Redis for asynchronous task processing, while deploying on GCP with Cloud Run and Firestore, enabling real-time scheduling, payment processing, and automated notifications
  • Mentored junior developers through code reviews, pair programming, and knowledge-sharing sessions, improving team efficiency by 30% while maintaining comprehensive API documentation using Swagger/OpenAPI
Aug 2018 - Apr 2021
2 years 9 months
Berlin, Germany

Senior Web Developer

Spotify

  • Architected high-throughput microservices in Java and Scala on Google Kubernetes Engine, leveraging Spring Boot and Akka HTTP to serve over 50 million playlist requests per day with 99.9% uptime
  • Built real-time event pipelines with Apache Kafka and Scio (Apache Beam/Dataflow), processing 1.2 billion user interactions daily to power personalized Discover Weekly and Release Radar playlists
  • Optimized metadata storage by tuning Apache Cassandra clusters—implemented advanced compaction and schema strategies that reduced 99th-percentile read latency from 120 ms to 45 ms and cut storage costs by 25%
  • Developed domain-driven .NET Core microservices for room-rate calculation and channel management, applying CQRS and event sourcing patterns for clear separation of concerns
  • Leveraged Docker Compose for local development and Azure Container Registry for production images, standardizing environments across teams
  • Implemented PostgreSQL partitioning and advanced indexing strategies, achieving sub-20 ms response times on 500 million+ row tables
  • Integrated Redis Streams to buffer burst traffic and smooth cache invalidation, reducing origin DB load by 70%
  • Consumed and produced to Kafka topics for cross-service messaging, ensuring reliable event delivery and simplifying inter-team contracts
  • Designed and deployed scalable serverless architectures for SaaS-based B2B and B2C applications using AWS Lambda, API Gateway, AWS AppSync, and DynamoDB, integrating AWS IAM for secure access control, while ensuring high availability, cost efficiency, and seamless auto-scaling
  • Designed and managed scalable infrastructure with AWS CDK and CloudFormation, streamlining deployments faster and more reliable across different environments
  • Optimized performance and cost by reducing cold start latency, using SQS & SNS for asynchronous processing, and implementing caching strategies with DynamoDB Accelerator (DAX) and Redis
  • Demonstrated strong problem-solving, communication, and collaboration skills, effectively working with cross-functional teams to deliver scalable solutions, streamline workflows, and drive project success in fast-paced environments
Jul 2016 - Jul 2018
2 years 1 month
Berlin, Germany

Frontend Engineer

Zalando

  • Developed a full-stack iGaming platform, integrating cryptocurrency payments (Bitcoin, Ethereum) via Web3 APIs, ensuring smooth transaction management, secure wallet operations, real-time gameplay features, and a scalable backend for enhanced user engagement and efficiency
  • Managed Firestore and Firebase Authentication on GCP, optimizing database performance, securing user authentication, and ensuring seamless integration with cloud services for scalable and reliable applications
  • Designed and led development of 12 domain-oriented C# 9/.NET 6 microservices (reservations, billing, loyalty) using CQRS via MediatR and event sourcing with Kafka
  • Conducted design sessions and code reviews in Mandarin with the China engineering squad, eliminating hand-off delays and boosting feature delivery by 35%
  • Employed Swashbuckle v6 to auto-generate OpenAPI 3.0 specs and Swagger UI, slashing frontend integration time by 50%
  • Packaged each service in Docker 20.10 containers and managed deployments on AKS (Kubernetes 1.25), cutting release cycles from days to hours
  • Modeled PostgreSQL 14 schemas with table partitioning and pgBouncer pooling; integrated Redis 6.2 as a distributed cache to reduce read latency by 80%
  • Configured and optimized Cloudflare and Nginx for secure, high-performance web applications, implementing CDN caching, DDoS protection, load balancing, and reverse proxy setups to enhance speed, security, and scalability
  • Collaborated with DevOps engineers to optimize and support CI/CD pipelines using GitHub Actions and Jenkins, streamlining automation and deployment processes for enhanced efficiency and reliability
Jun 2014 - Jun 2016
2 years 1 month

Software Consultant (Full Stack)

ThoughtWorks

  • Developed enterprise web applications using Ruby on Rails and React
  • Delivered agile consulting for fintech and healthcare clients
  • Developed backend functionality with Python and Java, optimizing data processing efficiency by 25% by applying OOP, SOLID principles, data structures, and algorithmic optimizations to improve performance
  • Gained hands-on experience with AWS and GCP, utilizing services like EC2, S3, Lambda, Cloud Functions, BigQuery, and Firestore to deploy, manage, and optimize cloud-based applications for scalability and performance

Summary

Bachelor-level educated, result-driven & solution-oriented software engineer who is passionate about solving complex problems.

Great remote team-player, who loves working at fast-paced, agile environment.

Skills

  • Programming Languages: Javascript (Es6+), Typescript, Node.js, Python, Html5, Css3, Xml, Json
  • Architecture & Apis: Microservices, Event-driven Architecture, Graphql, Rest Apis, Websocket Api, Webrtc
  • Backend Development: Nest.js, Express.js, Django (Drf), Fastapi, Rabbitmq, Apache Kafka, Grpc
  • Frontend Development: React, Redux, Next.js, React Native, Angular, Ngrx, Rxjs, Vue.js, Tailwindcss, D3.js, Three.js
  • Databases & Data Processing: Sql, Nosql, Postgresql, Mysql, Mongodb, Cassandra, Dynamodb, Clickhouse, Redis
  • Cloud & Devops: Aws, Gcp, Azure, Heroku, Docker, Kubernetes, Jenkins, Github Actions, Gitlab Ci, Circleci
  • Testing & Tools: Jest, Mocha, Chai, Pytest, React Testing Library, Cypress, Sentry, Datadog, Grafana, Celery
  • Agile & Project Management: Scrum, Kanban, Jira, Slack, Microsoft Teams, Trello, Asana, Notion
  • Soft Skills: Leadership, Cross-functional Team Collaboration, Communication, Problem-solving, Flexibility, Time-management

Languages

English
Advanced
Chinese
Advanced

Education

Aug 2012 - May 2016

National University of Singapore (NUS)

Bachelor of Computing in Computer Science · Computing in Computer Science · Singapore

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