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Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Senior Software Engineer, Backend (Card) - **Company:** Affirm - **Location:** Madrid, Spain (Remote available) - **Salary:** €86,000.0 - €122,000.0 - **Contract:** Permanent contract - **Skills:** Clean Code Principles, Amazon Web Services, Code Review, Python (Programming Language), MySQL, Transaction Processing (Computing), Backend, Kotlin, Kubernetes - **Published:** August 5, 2026 - **Apply:** https://es.indeed.com/viewjob?jk=598e8e093635c8d4 ## About the Role * You have a total of 4+ years of experience as a software engineer. * You are experienced in designing, developing and launching backend systems at scale technologies like Python, Kotlin, AWS, MySQL, and Kubernetes. * You have experience shipping front end applications * You have experience defining a technical plan for the delivery of a significant feature or system component with an elegant, simple and extensible design. You write high quality code that is easily understood and used by others. * You are proficient at making significant changes in a large code base, and have developed a suite of tools and practices that enable you and your team to do so safely. * Your experience demonstrates that you take ownership of your growth, proactively seeking feedback from your team, your manager, and your stakeholders. * You have strong verbal and written communication skills that support effective collaboration with our global engineering team. ## Description We are reinventing credit cards in the most transparent way possible. We are working directly with card issues to change how credit is used throughout the world, creating new types of cards that work for both their everyday lives and large purchases with extremely straightforward, flexible terms. You'll work across stacks and across the company, working both in just-in-time transaction processing that has to take place in milliseconds, along with our ledgering and reconciliation systems in post-transaction processing. This is some of the more difficult, exciting, experimental engineering work in Affirm. Join us and our team in Spain and Poland to help us revolutionize payments! What You'll Do * You will be responsible for owning and delivering quarterly goals for your team, leading engineers on your team through ambiguity to solve open-ended problems, and ensuring that everyone is supported throughout delivery. * You will support your peers and stakeholders in the product development lifecycle by collaborating with product management, design & analytics by participating in ideation, articulating technical constraints, and partnering on decisions that properly consider risks and trade-offs. * You will proactively identify project, process, technology or business issues, advocate for them, and lead in solving them. * You will support the operations and availability of your team's artifacts by creating and monitoring metrics, escalating when needed, and supporting "keep the lights on" & on-call efforts. * You will foster a culture of quality and ownership on your team by setting or improving code review and design standards for your team, and advocating for them beyond your team through your writing and tech talks. * You will help develop talent on your team by providing feedback and guidance, and leading by example. ## Related Videos - [Developing the Backend with Stefan Lingler, CTO at Shpock](https://www.wearedevelopers.com/videos/100360-developing-the-backend-with-stefan-lingler-cto-at-shpock) - [Inside Bitpanda's Tech Stack: Scaling a European Fintech Leader - Markus Dorner](https://www.wearedevelopers.com/videos/1979-inside-bitpanda-s-tech-stack-scaling-a-european-fintech-leader-markus-dorner) - [Kotlin Multiplatform - True power of native code reuse](https://www.wearedevelopers.com/videos/4-kotlin-multiplatform-true-power-of-native-code-reuse) - [MySQL Protocol Features You Should Be Aware Of](https://www.wearedevelopers.com/videos/100267-mysql-protocol-features-you-should-be-aware-of) - [Meet Your New BFF: Backend to Frontend without the Duct Tape](https://www.wearedevelopers.com/videos/682-meet-your-new-bff-backend-to-frontend-without-the-duct-tape) - [Back(end) to the Future: Embracing the continuous Evolution of Infrastructure and Code](https://www.wearedevelopers.com/videos/440-back-end-to-the-future-embracing-the-continuous-evolution-of-infrastructure-and-code) ## Related Articles - [Fully Remote Software Engineer Jobs](https://www.wearedevelopers.com/magazine/447-fully-remote-software-engineer-jobs) - [The 12 Best Jobs for Software Engineers](https://www.wearedevelopers.com/magazine/401-the-12-best-jobs-for-software-engineers) - [Is Software Engineering Over-Saturated?](https://www.wearedevelopers.com/magazine/418-is-software-engineering-over-saturated) - [Dev Digest 120 - Apple and peers](https://www.wearedevelopers.com/magazine/455-dev-digest-120-apple-and-peers) - [Navigating the AI Shift](https://www.wearedevelopers.com/magazine/629-navigating-the-ai-shift) - [Dev Digest 121 - AI goes offline](https://www.wearedevelopers.com/magazine/456-dev-digest-121-ai-goes-offline)