Lead Kotlin Backend Engineer

• Do you enjoy designing and owning backend systems where correctness, consistency and domain modelling matter?
• Do you want to work in a Kotlin-first environment that takes functional programming seriously?
• Are you a lead backend engineer who prefers clarity, strong abstractions and explicit trade-offs over accidental complexity?
• And do you want to work remote-first while shaping a core platform used across multiple countries and millions of users?

Then this role is built for you.

Your employer: a large-scale digital marketplace with deep operational complexity

You will join a well-established European digital platform operating at significant scale, used daily by customers across many regions. Behind the scenes sits a complex operational backbone that supports everything the business does.

Engineering here is deliberate. The organisation favours Kotlin-first backend development, strong domain modelling and functional principles to keep complexity manageable as the platform grows. Decisions are made for long-term maintainability. They combine product-driven development with real operational responsibility.

Engineering teams are trusted to make decisions, improve systems incrementally and take ownership over critical domains. There is little hierarchy, minimal bureaucracyand a strong focus on pragmatism and long-term maintainability.

The company operates remote-first, with only two office days per month in Amsterdam.

Your team: Platform / Back-office (business-critical systems) This team forms the operational heart of the platform. These systems are absolutely critical to the business.

The team is responsible for:

• complex business workflows
• integrations with systems such as ERP, CRM and internal tooling
• API-heavy services with many dependencies
• correctness, data consistency and long-term stability

The landscape consists of roughly 8-10 core backend services with deep domain logic and many integrations. These systems are mission-critical: when they fail, the business feels it immediately.

The team is currently being strengthened with permanent senior engineers to reduce dependency on externals and build a stable internal core.

Your role: Lead Kotlin Backend Engineer Amsterdam

In this role as Lead Kotlin Backend Engineer Amsterdam, you take ownership over a complex backend domain. You are not expected to rewrite everything. Instead, you bring structure, calm and technical judgement.

You work hands-on in Kotlin-based backend services and help evolve the platform incrementally. You influence architecture through experience, not dogma. You understand trade-offs and know when stability matters more than elegance.

You lead by example:

writing clear, maintainable backend code

improving service boundaries and data models

• 7+ years of professional backend engineering experience on the JVM
• Strong experience with Kotlin, Java or Scala with a passion for FP
• Experience working on complex, business-critical backend systems
• Strong understanding of data consistency, integrations and failure modes
• Experience designing and maintaining APIs
• Experience with event-driven and distributed systems
• Experience working in cloud-native environments
• Ability to bring structure to complex domains
• Strong communication skills and technical clarity
• Experience mentoring or guiding other engineers is a big plus
• Nice to have
• Deep Kotlin production experience
• Experience with Arrow, Ktor or similar FP-oriented tooling
• Experience with platform evolution or legacy modernisation

• Salary between €85.000 and €100.000 per year + 8% bonus
• Fully remote working from within the Netherlands
• Only 2 office days per month (Amsterdam)
• 25 vacation days
• Modern hardware and tooling
• High ownership role within a core platform team
• The opportunity to shape long-term backend stability and quality