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Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Software Engineer - **Company:** Raisin - **Location:** Madrid, Spain - **Contract:** Permanent contract - **Skills:** Clean Code Principles, ASP.NET, HTML, Java (Programming Language), JavaScript (Programming Language), .NET Framework, Application Programming Interfaces (APIs), Artificial Intelligence, Architectural Patterns, User Authentication, Automation of Tests, Software Bug Management, Code Review, Relational Databases, Software Design Patterns, Microsoft SQL Server, MongoDB, Node.Js, NoSQL, Nunit, OAuth, Performance Tuning, Web Applications, ReactJS, Spring-boot, Solid Principles, Graphql, React Testing Library, Api Design, Data Pipelines, Web Api, Golang - **Published:** July 26, 2026 - **Apply:** https://www.adzuna.es/contact-us.html ## About the Role We are looking for a versatile Senior Full-Stack Engineer with a deep, rock-solid foundation in the .NET and SQL Server ecosystem, who has the architectural maturity to adapt to other layers and the drive to learn the rest of our stack. Required: + Designing, optimizing, and maintaining robust enterprise APIs using .NET Web API. + Building and structuring web applications with .Net + Strong relational database design, complex querying, and performance tuning in SQL Server. + Design Patterns: A deep understanding of SOLID principles and a proven track record of writing Clean Code. + Structural Strategy: Practical experience working within modern architectural patterns, specifically Clean / Onion Architecture, to keep codebases decoupled and testable. + Fast Learner: You don't mind stepping out of your .NET comfort zone to touch a React component or a Go microservice. + Problem Solver: Highly analytical with a strong focus on detail and quality. + Collaborator: A team-first peer who thrives on open communication and cross-layer collaboration. Desired: + Experience building user interfaces with React JS, JavaScript, and HTML, accompanied by testing tools like Jest or React Testing Library. + Exposure to, or curiosity about environments like Node.js, GoLang, or Java / Spring Boot, and building APIs + Experience with GraphQL. + Working knowledge or conceptual familiarity with MongoDB or NoSQL Databases + Familiarity with NUnit for automated testing + Familiarity with secure authentication via OAuth and ASP.NET Identity. ## Description The US Payments & Partner Operations (PPO) team owns the core money-movement stack for the Raisin US' platform: ACH payment initiation, reconciliation, returns, and cut-off scheduling, plus the customer accounts lifecycle - bank linking, fraud signal integration, and identity verification. Beyond payments, the team manages the B2B layer: onboarding and configuring Deposit-taking Banks, service banks, and custodians, including their user/role management. It also covers invoicing data pipelines for Deposit taking banks, escheatment workflows for dormant accounts and visibility for operations and customer support through our internal platform portal. Your Responsibilities + Own and deliver features and bug fixes end-to-end with minimal guidance. + Identify and address bottlenecks in the team's delivery flow, from design to deployment. + Utilize AI tools intensively for increasing our ability and pace to deliver software. + Promote best practices around our core stack. + Transfer knowledge proactively, lead by example in learning and mentoring. + Contribute to improving how we program, test, review, and ship code. + Flag process gaps and propose pragmatic improvements. + Elevate engineers in growing their technical skills. + Provide constructive code review and solve complex problems together. + Quickly build practical depth in PPO's domains. + Contribute meaningfully to new feature design and implementation. + Bring engineering perspective into domain discussions alongside other team roles like Product Manager, Tech Lead and Engineering Lead. ## Related Videos - [The Resilience of the World Wide Web](https://www.wearedevelopers.com/videos/1281-the-resilience-of-the-world-wide-web) - [Keeping applications secure by evolving OAuth 2.0 and OpenID Connect](https://www.wearedevelopers.com/videos/100152-keeping-applications-secure-by-evolving-oauth-2-0-and-openid-connect) - [Build and Deploy a Fullstack App with Open Source Tooling](https://www.wearedevelopers.com/videos/775-build-and-deploy-a-fullstack-app-with-open-source-tooling) - [NoLoJS - Avoiding JavaScript Cruft with HTML and CSS - Aaron T. Grogg](https://www.wearedevelopers.com/videos/1806-nolojs-avoiding-javascript-cruft-with-html-and-css-aaron-t-grogg) - [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) - [Delay the AI Overlords: How OAuth and OpenFGA Can Keep Your AI Agents from Going Rogue](https://www.wearedevelopers.com/videos/1637-delay-the-ai-overlords-how-oauth-and-openfga-can-keep-your-ai-agents-from-going-rogue) ## Related Articles - [Fully Remote Software Engineer Jobs](https://www.wearedevelopers.com/magazine/447-fully-remote-software-engineer-jobs) - [Where To Find Software Engineering Jobs](https://www.wearedevelopers.com/magazine/396-where-to-find-software-engineering-jobs) - [Find a Developer Job: 12 Best Job Sites For Developers](https://www.wearedevelopers.com/magazine/165-find-a-developer-job-12-best-job-sites-for-developers) - [Where to Find Entry-Level Software Engineering Jobs](https://www.wearedevelopers.com/magazine/397-where-to-find-entry-level-software-engineering-jobs) - [16 Best Free React UI Libraries in 2025](https://www.wearedevelopers.com/magazine/148-16-best-free-react-ui-libraries-in-2025) - [The 12 Best Jobs for Software Engineers](https://www.wearedevelopers.com/magazine/401-the-12-best-jobs-for-software-engineers)