Piotr W.

Senior Software Engineer

Łódź, Poland

Experience

Sep 2023 - Present
2 years 2 months
United States

Senior Software Engineer

Iron Mountain

  • Developed microservices-based backend systems for fintech, food delivery, and SaaS platforms using Go (Golang), Node.js (Express.js), and Python (Flask), focusing on performance, scalability, and reliability.
  • Achieved sub-100ms response times in a fintech platform by implementing gRPC for inter-service communication and optimizing PostgreSQL schemas for transaction-heavy operations.
  • Designed event-driven architectures using Apache Kafka and RabbitMQ, supporting real-time fraud detection, notification systems, and dashboard updates across high-volume environments (1M+ daily events).
  • Built serverless components with AWS Lambda for use cases including transaction alerts, payment status updates, file transformations, and real-time notifications.
  • Leveraged Redis and DynamoDB to optimize data access and caching across order management, user settings, and restaurant menu systems, significantly reducing backend load and improving API response times.
  • Deployed containerized services on AWS ECS Fargate and Kubernetes (EKS) for auto-scaling, fault-tolerant infrastructure capable of handling peak loads in production environments.
  • Configured AWS SNS for real-time push notifications to customers, drivers, and end-users, enabling responsive user experiences across web and mobile.
  • Implemented CI/CD pipelines using GitHub Actions, streamlining automated testing, secure deployments, and infrastructure updates across environments.
  • Automated infrastructure provisioning using Terraform, cutting setup time by 60% and improving consistency across staging and production.
  • Monitored system health and performance using Prometheus, Grafana, and the ELK stack, ensuring visibility across all services and enabling quick incident response.
  • Designed and executed disaster recovery strategies using AWS Backup and cross-region replication, ensuring data resilience and business continuity.
Jan 2016 - Aug 2023
7 years 8 months
Denmark

Backend Engineer

Unity Technologies

  • Built a GraphQL API to eliminate over-fetching and improve client-side performance by 30%, enabling real-time interactions like likes, comments, and messages via WebSockets.
  • Designed a high-performance microservices backend using Go (Golang), leveraging Apache Kafka for event-driven updates to user feeds and notifications.
  • Stored user-generated content in MongoDB to support flexible schema evolution and high-volume writes.
  • Implemented secure user authentication using OAuth2 and JWT tokens.
  • Deployed services on Kubernetes (EKS), ensuring seamless scaling during traffic spikes.
  • Integrated Datadog for full-stack observability and rapid issue diagnosis.
  • Developed a low-latency backend for a mobile gaming platform using Go (Golang), supporting real-time multiplayer gameplay.
  • Modeled real-time game state in DynamoDB, optimized for speed and scalability.
  • Set up Apache Kafka to handle player events and game logic updates asynchronously.
  • Delivered game assets globally with AWS CloudFront CDN for faster load times.
  • Used AWS Lambda to handle in-game purchase processing and receipt validation.
  • Implemented centralized logging with the ELK stack for streamlined monitoring and debugging.
  • Monitored backend health with Prometheus and Grafana, enabling proactive alerting and performance tuning.
  • Built a disaster recovery strategy using AWS Backup with cross-region replication for high availability.

Summary

Senior Backend Engineer with over 10 years of experience in building robust, high-performance systems for both startups and large-scale enterprises. Specialized in backend development, distributed systems, and DevOps, with a strong focus on reliability and scalability.

Highly proficient in Go (Golang), and well-versed in Python, Java, and Node.js. Skilled in designing microservices architectures, implementing event-driven systems, and optimizing backend services for speed and resilience. Experienced in site reliability engineering, CI/CD automation, and infrastructure-as-code using AWS and Terraform. Passionate about writing clean, maintainable code and delivering backend platforms that enable rapid product iteration and long-term technical stability.

Languages

Danish
Advanced
English
Elementary

Education

Oct 2017 - Jun 2019

EK – Erhvervsakademi København

Master’s Degree · Computer Science · Denmark

Oct 2014 - Jun 2017

EK – Erhvervsakademi København

Bachelor’s Degree · Computer Science · Denmark

Need a freelancer? Find your match in seconds.
Try FRATCH GPT
More actions