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# Mid-Level Backend Developer

- **Company:** Genki
- **Location:** Madrid, Spain (Remote available)
- **Salary:** €60,000.0
- **Contract:** Permanent contract
- **Skills:** Artificial Intelligence, Business Logic, Software Quality, Programming Tools, Backend, Kotlin, Event Driven Architecture, Heroku, Event Sourcing
- **Published:** August 21, 2026
- **Apply:** https://www.buscojobs.com.es/mid-level-backend-developer-en-madrid-ID-368475713

## About the Role

You should have some hands-on experience with these tools and a genuine drive to go deeper.ExperienceYou've worked on larger backend systems in production and understand the complexity they bring.You've worked in complex product domains and can ramp up quickly on business logic that isn't always obvious.You're comfortable with event sourcing, event-driven architecture, or similar patterns.You care about code quality: readable code, meaningful tests, and clean APIs.You have some experience with AI-agentic development tools (Claude Code, Codex, or similar) and want to go deeper.Our current tech stackLanguage: Kotlin with coroutinesFramework: Custom, built around event sourcingBilling: StripeInfrastructure: Heroku (migrating to Railway)AI-agentic development: Claude Code with custom pluginAPIs: GraphQLWorking styleYou pay close attention to the details and take pride in getting them right.You're curious and self-driven.

## Description

Genki means "healthy, energetic, and full of spirit".That's us.We're a fully remote, profitable startup of about 25 people, five years in and growing steadily.We build tailored health insurance for long-term travelers like digital nomads, serving over 75,000 people in 200 countries.Our vision is to help them stay healthy wherever they go, far beyond insurance.We're looking for a Mid-Level Backend Developer to help build and evolve the core system that powers our products and operations.You'll join as the second developer in our backend team, reporting to our Lead Backend Developer.Our backend runs on Kotlin with a custom framework built around event sourcing.It's not yet fully documented, so you'll need to be comfortable reading code, asking questions, and finding your way through a system that's still being shaped.You'll build new features, improve testability and reliability, and help evolve the architecture over time.The product is complex and spans multiple domains.You'll need to build deep understanding quickly and be comfortable making decisions with incomplete information.We're moving fast, increasingly with AI-agentic development tools.You should have some hands-on experience with these tools and a genuine drive to go deeper.ExperienceYou've worked on larger backend systems in production and understand the complexity they bring.You've worked in complex product domains and can ramp up quickly on business logic that isn't always obvious.You're comfortable with event sourcing, event-driven architecture, or similar patterns.You care about code quality: readable code, meaningful tests, and clean APIs.You have some experience with AI-agentic development tools (Claude Code, Codex, or similar) and want to go deeper.Our current tech stackLanguage: Kotlin with coroutinesFramework: Custom, built around event sourcingBilling: StripeInfrastructure: Heroku (migrating to Railway)AI-agentic development: Claude Code with custom pluginAPIs: GraphQLWorking styleYou pay close attention to the details and take pride in getting them right.You're curious and self-driven.You dig into unfamiliar code, ask good questions, and figure things out.You'd rather understand why something works than just make it work.You're comfortable making decisions when not all the information is there yet.You've worked in a startup or scaleup and know what that pace and ambiguity feels like.You thrive in a fully remote, async-first team and know how to communicate clearly without meetings for everything.You're as open to different ideas, opinions, and to people with different cultures, backgrounds, and interests as we are.Up to 5,000 EUR/month (depending on experience) with employee equity participation through a vesting programFully remote, from anywhere in the world & live as a digital nomad if you want to (the country list above are just examples)Flexible hours, startup atmosphereMost of the team is in Europe and Southeast Asia, with a few hours of daily overlap around German business hoursCompany-issued and managed MacBook, plus a desk in your favorite co-working space25 days paid annual leaveRegular team off-sites to connect in person#J-*****-Ljbffr


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