> Markdown version of [/jobs/ext/2020638-backend-senior-developer](https://www.wearedevelopers.com/jobs/ext/2020638-backend-senior-developer). Every page supports `.md` or `Accept: text/markdown`. Links point to the HTML versions so they work for humans too. Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Backend Senior Developer - **Company:** Esims - **Location:** Spain (Remote available) - **Contract:** Permanent contract - **Skills:** Java (Programming Language), JavaScript (Programming Language), .NET Framework, Application Programming Interfaces (APIs), Agile Methodology, Amazon Web Services, User Authentication, Distributed Systems, OAuth, Data Streaming, Wireless Networks, File Transfer Protocol (FTP), ReactJS, Delivery Pipeline, SOAPAPI, Backend, Vue.js, Information Technology, Front End Software Development, Software Coding, Restful APIs, Golang, Programming Languages - **Published:** August 11, 2026 - **Apply:** https://es.trabajo.org/oferta-4021-dc4145295fb6e3f17f270fb885c6e283 ## About the Role designing even driven architectures using queues, streaming, etc. - Experience writing code in Golang programming language. - Experience working in AWS cloud environment. - Experience working in Agile environments. - Experience in some older technologies such as CLIs, SOAP services, FTP, etc. - Experience working in a multicultural, multidisciplinary environment. - Fluent in both written and spoken English. - Familiar with API and WebApps security standards and authentication methods (API key, JWT token, OAuth 2.0, etc). Preferred skills and experience: * Bachelor degree in Computer Science, Mathematics or equivalent. * Experience in other programming languages like Java, .NET or Javascript. * Experience writing IaC scripts and managing CI/CD pipelines. * Familiar with Frontend technologies such as Vue.js or React.js. * Experience communicating with stakeholders and/or customers. * Experience integrating with core Telecommunications platforms such as OCS, BSS, PGW, PCRF and equivalent across 3/4/5G generations as used by MNO/MVNOs * Extensive knowledge about mobile networks and telephon What we offer: * Full-time permanent role, based remotely * Competitive salary * Fast-growing international company * A great, supportive team to work with * The possibility to develop an innovative product in a new market within an international context * Private health insurance * English/Spanish classes * International experience * A comfortable office based in the city center of Valencia, next to the metro stop * Hybrid Work Model, flexible working hours combined with remote work * Nice social environment with a game room, joint lunches, drinks, and regular parties - Training budget 500€ per year and 700€ for referrals - Flexible remuneration Hybrid - Valencia, Comunidad Valenciana, Spain €35 - €55 per year IT All done Your application has been successfully submitted Other jobs You've already applied for this job We appreciate your interest in this position. Unfortunately, you have already applied for this job. ## Description Job description About our client A technology platform that enables companies (of any size) to offer digital connectivity services through eSIMs, with fast implementation, no initial investment, and global scalability through a unified technology. You'll be responsible for improving and maintaining our internal APIs and Supplier integrations. You'll be involved in the product lifecycle from ideation to deployment to maintenance, making sure we build a robust and scalable solution. You'll work closely with the Product and Reseller teams to build the underlying platform that powers our customer-facing APIs. You will be working in a multidisciplinary team where you'll be the driving force behind the backend tasks. Job requirements What we're looking for: - 3+ years of experience working as a Senior Backend Developer. - Strong computer science foundations, mostly working in distributed systems. - Extensive experience writing scalable APIs using REST architecture. - Extensive experience ## Related Videos - [Unlocking the potential of Digital & IT at Vodafone](https://www.wearedevelopers.com/videos/602-unlocking-the-potential-of-digital-it-at-vodafone) - [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) - [Lessons learned from building a thriving Vue.js SaaS application](https://www.wearedevelopers.com/videos/1666-lessons-learned-from-building-a-thriving-vue-js-saas-application) - [Go with the Flow: Stop the Leaks Before Your Memory's a Waterfall!](https://www.wearedevelopers.com/videos/100073-go-with-the-flow-stop-the-leaks-before-your-memory-s-a-waterfall) - [Migrating half a million users to a new payment service provider](https://www.wearedevelopers.com/videos/730-migrating-half-a-million-users-to-a-new-payment-service-provider) - [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) - [Spanish Business Culture and Etiquette](https://www.wearedevelopers.com/magazine/353-spanish-business-culture-and-etiquette) - [Top-Paying Tech Jobs (with Salaries)](https://www.wearedevelopers.com/magazine/372-top-paying-tech-jobs-with-salaries) - [Is Software Engineering Over-Saturated?](https://www.wearedevelopers.com/magazine/418-is-software-engineering-over-saturated) - [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)