Senior Software Engineer | API at Deepl · LumiJobs · LumiJobs

Responsibilities

We are shifting gears from "Software-First" to "Product-First." We don't hire engineers to simply maintain legacy endpoints or close Jira tickets. We hire Missionaries—builders who obsess over the Why before the How . You will balance strategic platform architecture with tactical feature delivery, working across the stack to create delightful, frictionless experiences for both external developers and internal engineering teams.
Your responsibilities
Drive "DevEx Delight": You will own and transform the experience of developers using DeepL APIs. You will streamline the entire journey—from anonymous visitor to activated developer—by building intuitive self-service experiences, seamless onboarding flows, and advanced customization interfaces .
Platform Enablement & Scale: You won't just write endpoints; you will build the ecosystem. You will create reusable components, comprehensive documentation, starter templates, and client libraries (SDKs) that empower customers and ISVs to build AI-enabled products rapidly.
Cross-Functional Architecture: You will act as the API standard-bearer across DeepL. Partnering with Enterprise (BAT), Core Text, Voice, and Customization teams, you will drive continuous improvement and maintain the highest standards for the consistency, security, and reliability of all customer-facing APIs.
Guardianship of Quality & Compliance: You will implement automated quality gates, strict contract testing, and robust monitoring infrastructure. You will prevent breaking changes and security vulnerabilities before they hit production, shaping the API design standards and operational excellence practices for our growing platform .
Qualities we look for
A "Product-First" API Mindset: You treat developers as your primary users. You understand that a successful API relies on reducing cognitive load, creating clear abstractions, and providing stellar documentation, not just fast response times.
Backend Mastery & Full-Stack Capability: You have deep expertise in designing scalable backend systems, RESTful APIs, and distributed architectures (using Go, Python, Java, C#, or similar). You are also comfortable crossing the stack, using modern frontend frameworks (React/TypeScript) to build developer-facing dashboards, signup flows, and configuration UIs.
Extreme Ownership & Operational Excellence: You have a track record of owning services end-to-end. You don't just ship code; you own production operations, incident response, and continuous improvement. You write comprehensive tests, learn from incidents, and treat mature SLOs as a core engineering feature .
AI-Native Velocity: You leverage AI-powered tools (like GitHub Copilot or Claude) to accelerate your velocity and eliminate repetitive toil. You use AI for boilerplate code, test generation, and debugging, allowing you to focus your cognitive energy on high-value architectural decisions and complex problem-solving.

Senior Software Engineer | API

Responsibilities

Company

Deepl

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