Senior Backend Software Engineer

Quick Facts

• Salary: 1200–1360 PLN/day net + VAT (B2B)

• Work model: Hybrid (1 day per week from the Gdańsk office)

Description

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

Responsibilities

• Design, develop and optimise serverless and event-driven backend services on AWS

• Improve AWS architecture for cost, performance, scalability and resilience

• Optimise event stream processing: throughput, latency, message ordering, retries and error handling

• Improve PostgreSQL performance through query optimisation, indexing, partitioning and data modelling

• Implement observability solutions: metrics, distributed tracing, alerting and SLOs

• Ensure code quality with unit and integration testing, plus load and performance testing

• Contribute to architectural discussions and evaluate technical trade-offs

Benefits

• Flexible work organization

• International environment with daily English usage

• Integration meetings and a supportive “Jit community”

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 understanding of event-driven architecture and message processing (idempotency, retries, dead-letter queues, schema evolution)

• Strong PostgreSQL optimisation skills (query analysis, indexing, partitioning, connection pooling and replication)

• Experience with database migrations, backups and point-in-time recovery

• Experience with Infrastructure as Code, particularly CloudFormation

• Knowledge of unit, integration, load and performance testing

• Excellent communication skills, proactive approach to architecture and technology, and proficiency in written and spoken English