Senior Backend Software Engineer

Quick Facts

• Role: Senior Backend Software Engineer (Remote)
• Salary: 1200–1360 PLN/day net + VAT (B2B)

Description

Join a mature, self-organised agile team building customer-facing tracking products. The project consolidates tracking channels into a single customer entry point, introduces new customer notifications, and scales event-driven APIs.

Responsibilities

• Design, develop, and optimize serverless, event-driven backend services on AWS
• Improve AWS architecture for cost, performance, scalability, and resilience
• Optimize event stream processing: throughput, latency, message ordering, retries, and error handling
• Improve PostgreSQL performance through query optimization, indexing, partitioning, and data modelling
• Implement observability: metrics, distributed tracing, alerting, and SLOs
• Ensure code quality with unit and integration testing, plus load and performance testing
• Participate in architectural discussions and evaluate technical trade-offs

Requirements

• 5+ years of back-end development experience with Python or Scala
• 5+ years of hands-on AWS experience in production
• Experience with AWS services: API Gateway, Step Functions, ECS/Fargate, SQS, SNS, EventBridge, Kinesis and/or Amazon MSK (Kafka)
• Knowledge of RDS/Aurora PostgreSQL, DynamoDB, and S3
• Strong event-driven architecture knowledge (idempotency, retries, dead-letter queues, schema evolution)
• Strong PostgreSQL optimization skills (query analysis, indexing, partitioning, connection pooling, replication)
• Experience with database migrations, backups, and point-in-time recovery
• Experience with Infrastructure as Code, especially CloudFormation
• Knowledge of unit, integration, load, and performance testing
• Excellent written and spoken English; proactive approach to architecture and technology

Benefits

• Flexible work organization
• International environment with daily interaction in English
• Integration meetings through the Jit community