Patrick S.
Senior Software Engineer
Experience
May 2021 - Sep 2025
4 years 5 monthsBerlin, 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 monthsBerlin, 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 monthBerlin, 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 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 monthSoftware 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
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.
Languages
English
AdvancedChinese
AdvancedEducation
Aug 2012 - May 2016
National University of Singapore
Bachelor of Computing · Computer Science · Singapore
Need a freelancer? Find your match in seconds.
Try FRATCH GPT More actions
Similar Freelancers
Discover other experts with similar qualifications and experience
- English
- Deutsch
2025 © FRATCH.IO GmbH. All rights reserved.