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Daniel Jasinski

Senior Software Engineer

Daniel Jasinski
Rzeszów, Poland

Experience

Feb 2020 - Present
6 years

Senior Software Engineer

Sii Poland

  • Built a microservices-based backend for tracking system using Go (Golang), achieving sub-100ms response times.
  • Implemented gRPC for real-time communication between microservices, reducing latency by 40%.
  • Designed and optimized PostgreSQL schemas for transaction processing and user account management.
  • Set up Apache Kafka for event sourcing in a fraud detection system, enabling real-time transaction analysis.
  • Implemented serverless functions using AWS Lambda for processing transaction notifications.
  • Configured AWS RDS with read replicas for high availability and performance.
  • Designed and implemented a CI/CD pipeline using GitHub Actions, enabling frequent and reliable deployments.
  • Set up Prometheus and Grafana for monitoring transaction processing and system health.
  • Automated infrastructure provisioning using Terraform, reducing setup time by 60%.
  • Developed an event-driven notification system using Apache Kafka, processing 1M+ events daily.
  • Built a RESTful API for order management using Python Flask, ensuring seamless integration with mobile apps.
  • Implemented Redis for caching restaurant menus and order statuses, reducing database load.
  • Designed and optimized DynamoDB tables for storing real-time order data.
  • Set up RabbitMQ for asynchronous communication between order processing and delivery services.
  • Deployed the application on AWS ECS Fargate, ensuring scalability during peak hours.
  • Configured AWS SNS for sending push notifications to delivery partners and customers.
  • Implemented AWS Lambda for processing payment status updates and refunds.
  • Set up centralized logging using the ELK stack for troubleshooting and analytics.
  • Designed and implemented a disaster recovery plan using AWS Backup and cross-region replication.
  • Developed a microservices-based backend for a SaaS platform using Node.js and Express.js, ensuring scalability.
  • Implemented Redis for caching frequently accessed user data, reducing API response times.
  • Designed and optimized PostgreSQL schemas for storing user data and application settings.
  • Set up Apache Kafka for event-driven updates to user dashboards and notifications.
  • Deployed the application on Kubernetes (EKS) for high availability and scalability.
  • Configured AWS SNS for sending push notifications to users.
  • Implemented AWS Lambda for processing user uploads and transformations.
  • Set up centralized logging using the ELK stack for troubleshooting and analytics.
  • Designed and implemented a disaster recovery plan using AWS Backup and cross-region replication.
  • Configured Prometheus and Grafana for monitoring API performance and system health.
Oct 2014 - Dec 2019
5 years 3 months

Software Developer

Connected Digital Ltd

  • Developed backend microservices in Golang for image metadata management and user content feeds, leveraging Go’s high concurrency support.
  • Built a serverless image processing pipeline using AWS Lambda and S3 for a photo-sharing app.
  • Designed and optimized DynamoDB tables for storing media metadata and user interactions.
  • Set up Apache Kafka for event-driven updates to user feeds and notifications.
  • Deployed the application on Kubernetes (EKS) for high availability and scalability.
  • Configured AWS CloudFront for CDN to improve media delivery times for global users.
  • Implemented AWS Lambda for processing media uploads and transformations.
  • Set up centralized logging using the ELK stack for troubleshooting and analytics.
  • Built high-throughput APIs using Golang for real-time shipment tracking, replacing performance bottlenecks in legacy Python code.
  • Developed an event-driven architecture using AWS EventBridge and SQS for a logistics tracking system.
  • Built a RESTful API for shipment tracking using Python Flask, ensuring seamless integration with mobile apps.
  • Implemented Redis for caching frequently accessed shipment data, reducing database load.
  • Designed and optimized DynamoDB tables for storing real-time shipment data.
  • Set up RabbitMQ for asynchronous communication between shipment processing and tracking services.
  • Deployed the application on AWS ECS Fargate, ensuring scalability during peak hours.
  • Configured AWS SNS for sending push notifications to drivers and customers.
  • Implemented AWS Lambda for processing shipment status updates and notifications.
  • Set up centralized logging using the ELK stack for troubleshooting and analytics.
  • Designed and implemented a disaster recovery plan using AWS Backup and cross-region replication.
Sep 2011 - Oct 2014
3 years 2 months

Software Developer

University of Information Technology and Management

  • Developed a GraphQL API for a social media app, reducing over-fetching and improving client-side performance by 30%.
  • Implemented WebSocket-based real-time notifications for user interactions (likes, comments, messages).
  • Designed a microservices architecture using Go (Golang) for high-performance backend services.
  • Utilized Apache Kafka for event-driven updates to user feeds and notifications.
  • Set up MongoDB for storing user-generated content, ensuring scalability and flexibility.
  • Implemented OAuth2 and JWT-based authentication for secure user access.
  • Deployed the application on Kubernetes (EKS) for seamless scaling during peak traffic.
  • Configured Datadog for end-to-end observability, enabling quick troubleshooting of performance bottlenecks.
  • Developed a high-performance backend for a mobile gaming app using Go (Golang), achieving low-latency gameplay.
  • Implemented Redis for caching frequently accessed game data, reducing API response times.
  • Designed and optimized DynamoDB tables for storing real-time game data.
  • Set up Apache Kafka for event-driven updates to game state and player interactions.
  • Deployed the application on Kubernetes (EKS) for high availability and scalability.
  • Configured AWS CloudFront for CDN to improve game asset delivery times for global users.
  • Implemented AWS Lambda for processing in-game purchases and receipts.
  • Set up centralized logging using the ELK stack for troubleshooting and analytics.

Summary

Senior Backend Engineer with over 12 years of hands-on experience delivering robust backend systems and infrastructure for both startups and large-scale platforms. Focused on building reliable, maintainable services using Go, and also well-versed in Python, Java, and Node.js. Skilled in architecting microservices and event-driven systems, with a strong emphasis on performance tuning and operational stability. Experienced in DevOps practices including CI/CD pipelines, infrastructure provisioning, and cloud-native deployments on AWS. Brings a systems-thinking mindset to backend engineering—designing solutions that are efficient, scalable, and easy to evolve.

Skills

  • Backend Development: Graphql, Grpc, Rest Apis, Java, Go (Golang), Python, Node.js (Typescript, Javascript), Apache Kafka, Rabbitmq, Prometheus, Grafana, Datadog, Elk
  • Aws: Ec2, Ecr, Ecs, Cks, Fargate, Api Gateway, Eventbridge, Sqs, Sns, Lambdas, Cdk, S3, Dynamodb, Rds
  • Devops: Docker, Kubernetes, Github Actions, Ci/cd Designing, Aws Ec2, Ecr, Ecs, Eks, Terraform
  • Database: Postgresql, Mongodb, Mysql, Redis, Dynamodb, Cassandradb, Neo4j

Languages

Polish
Native
English
Advanced

Education

Oct 2011 - Jun 2012

University of Information Technology and Management

Master’s degree, Computer Science · Computer Science · Rzeszów, Poland

Oct 2007 - Jun 2011

University of Information Technology and Management

Bachelor’s degree, Computer Science · Computer Science · Rzeszów, Poland

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