Senior Python Engineer

Back to all rolesSenior Python Engineer -FinCrimeApplyJob detailsEngineeringMilan, StockholmFull-time€63,236 EUR - €70,825 EURWhat you will doYou will own Python services end-to-end — designing, building, shipping, and operating Lambdas and APIs that Klarna's investigation agents depend on around the clock. Working within a distributed system of Python Lambdas, Kafka streams, REST APIs, Elasticsearch clusters, and DynamoDB tables, you will reason across a fleet of services and keep a current understanding of how dozens of components hand off work via SNS topics, SQS queues, and API calls. You will debug across service boundaries, tracing individual orders or banking events through multiple layers to pinpoint issues using CloudWatch Logs and Datadog. A key part of your contribution will be translating between business and engineering, absorbing requirements from risk, product, and CX stakeholders, turning them into concrete designs, and communicating outcomes clearly to non-technical audiences. You will also master the messaging patterns that underpin the platform, including SNS fan-out, SQS with DLQs, idempotency, and back-pressure handling.Who you areProficient in Python 3.11+, with production experience in async code and typed models using Pydantic.Experienced with FastAPI or an equivalent Python web framework, including authentication, validation, and operating behind API Gateway.Hands-on with AWS serverless technologies including Lambda, SNS, SQS with DLQs, API Gateway, CloudWatch, IAM, and DynamoDB.Skilled in operating Elasticsearch at scale, including query DSL, index lifecycle management, and cluster tuning.A strong communicator who can work directly with non-technical stakeholders, understand their needs, and explain technical outcomes in plain language.Awesome to haveFamiliarity with TypeScript and React, with the ability to trace bugs into a frontend codebase and make small changes.Working knowledge of Java, enabling cross-team debugging with upstream services.Experience with Kafka streams and event-driven architecture patterns.Background in platform or infrastructure engineering within a distributed systems environment.Please include a CV in EnglishCurious to learn more about Klarna and what it's like to work here? Explore our career site!Upload your resume to autofill the applicationUploadFirst name *Last name *Email *Dial codePhone numberLinkedIn profile *Please upload your resume (preferably as a PDF file) *Click or drag file to uploadSupported file format: .PDF; Maximum file size: 10.49 MB; Maximum file: 1;AI disclaimerThis application process may use AI-enabled systems to support candidate evaluation based on factors such as experience, technical skills, and qualifications. All processing is carried out in accordance with applicable data protection, AI governance, and labour laws. Human oversight is maintained at all stages, and final hiring decisions are made by people. Personal data submitted as part of this application is not used to train AI models.I have read and understood the privacy policy and acknowledge that my personal data will be processed as part of this application.ApplyApplyHire withPrivacy Policy