Senior Fullstack Engineer — Merchant Platform (Hybrid)

Wolt; Helsinki; Hybrid; EUR 90,000 - 120,000; Full time

Job summary

Wolt in Helsinki or Berlin seeks a Fullstack Engineer to contribute to merchant-focused products across onboarding, analytics, recommendations, menu and order management, and integrations.

You will build production software across backend and frontend, collaborating with product, design, and operations to turn business needs into practical technical solutions. You’ll own features end-to-end and apply AI-assisted tools where appropriate.

Qualifications

• AI-first mindset with experience leveraging AI tools to solve problems end-to-end.
• Proven experience building production software in backend, frontend, or fullstack environments end-to-end and at scale.
• Strong expertise in at least one area of the stack, with willingness to contribute outside that area when needed.
• Experience with a modern backend language such as Go, Kotlin, Java, or similar, and/or modern frontend technologies such as TypeScript and React.
• Good understanding of APIs, databases, testing, and software design fundamentals.
• The ability to work independently on well-scoped problems and collaborate effectively with others.
• Good communication skills and a pragmatic, collaborative mindset.

Responsibilities

• Build and maintain production software across backend services and user-facing applications.
• Work on areas such as merchant onboarding, analytics, recommendations, menu and order management, integrations, or merchant-facing tools.
• Develop reliable APIs, data models, services, and user-facing features.
• Collaborate closely with product managers, designers, operations, and other engineers to turn business needs into practical technical solutions.
• Own features from implementation through production and ongoing maintenance.
• Contribute to technical design discussions and improve the quality, scalability, observability, and maintainability of our systems.
• Use AI-assisted development tools effectively as part of your engineering workflow, while critically evaluating their output and taking ownership of the final solution.
• Be willing to work outside your primary area of expertise when needed to solve the problem end-to-end.

Skills

AI-first mindset

Production software

Fullstack experience

Go/Kotlin/Java

TypeScript/React

APIs & databases

Independent work

Communication

Tools

Kafka

PostgreSQL

MongoDB

Redis

AWS

Kubernetes

Docker

gRPC

Job description

Wolt in Helsinki or Berlin seeks a Fullstack Engineer to contribute to merchant-focused products across onboarding, analytics, recommendations, menu and order management, and integrations.

You will build production software across backend and frontend, collaborating with product, design, and operations to turn business needs into practical technical solutions. You’ll own features end-to-end and apply AI-assisted tools where appropriate.