Lead Developer Senior Software Engineer Python AWS React

Lead Developer / Senior Software Engineer (Python, AWS, React) Rate: 1000-1200 PLN/month B2B (Senior), 1200-1400 PLN/month B2B (Lead) Work mode: Remote About the position We are looking for a Senior Software Engineer to join a team developing a cloud-native platform standardizing clinical trial data to the CDISC SDTM model at scale. You will work on both a Python and AWS-based backend and a React frontend, being responsible for end-to-end functionalities – from designing data processing pipelines to a mapping specification creation tool used by analysts. This is a hands-on engineering role with a real impact on the industry – the data generated by your code is used in regulatory submissions, safety analyses, and clinical trial outcome assessments. Scope of responsibilities Designing and developing a data transformation engine to the SDTM standard – orchestration using AWS Step Functions, AWS Lambda functions, and Databricks write paths. Creating and developing a GraphQL/AppSync-based API and a React frontend application, which analysts use to create data mapping specifications. Responsibility for Infrastructure as Code changes using Terraform, both in service stacks and shared infrastructure. Participation in code reviews, architectural discussions, and on-call duties. Mentoring less experienced engineers in applied technologies or in the clinical data domain. Requirements Minimum 5 years of commercial software engineering experience 8+ years of experience for a Lead Developer position English language proficiency at B2/C1 level Very good knowledge of Python – fluent work with Lambda Powertools, pytest/pytest-bdd and writing clean, testable code in a monorepo environment. In-depth knowledge of AWS, in particular: We expect not only the ability to run solutions but also an understanding of costs, latencies, and failure scenarios. Lambda, Step Functions, S3, DynamoDB, IAM. Nice to have Experience with GraphQL / AWS AppSync – designing schemas, resolvers, and integrating AppSync with a React application. React + TypeScript – willingness to work on an SPA application based on Vite and Cloudscape, without needing to be a frontend specialist. Experience with Terraform – creating, developing, and diagnosing configurations spanning multiple infrastructure stacks. Knowledge of Databricks or similar big data processing platforms. Knowledge of clinical data standards (CDISC SDTM, ADaM) or experience in developing software for regulated industries (e.g., GxP, 21 CFR Part 11). Good knowledge of event-driven architecture patterns and distributed systems, such as: fan-out / fan-in, idempotency, at-least-once delivery.