Senior Backend Engineer - Global Marts (Go/Kotlin)

wolt; Helsinki; On-site; EUR 90,000 - 120,000; Full time

Job summary

Wolt in Helsinki seeks a Senior Backend Engineer to own production systems, mainly using Go or Kotlin, and drive end-to-end technical initiatives.

You will design, build, and operate backend systems that support inventory, purchasing, and fulfillment, collaborating with product, data science, and operations teams to deliver scalable solutions.

Strong fundamentals in APIs, databases, and observability, plus comfort with data-heavy platforms like Kafka and Snowflake, are essential.

Qualifications

• Experience designing, building, and operating production backend systems.
• Professional experience with Go, Kotlin, or another modern backend language.
• Experience owning services end-to-end, including design, implementation, deployment, monitoring, and production operations.
• Strong knowledge of APIs, databases, asynchronous processing, failure handling, testing, and observability.
• Comfort with data-heavy systems and technologies such as Kafka, Snowflake, or similar streaming and data infrastructure.
• Ability to navigate ambiguous problems, break them into actionable steps, and deliver incrementally.
• Excellent communication and collaboration across teams.

Responsibilities

• Design, build, and operate backend systems that support inventory, purchasing, warehouse operations, pricing, and fulfillment.
• Own technical solutions from problem definition and design through implementation, deployment, monitoring, and production operation.
• Work on data-heavy systems where software engineering meets forecasting, optimization, and operational decision-making.
• Turn complex and ambiguous business problems into pragmatic, scalable technical solutions.
• Make architectural decisions balancing scalability, reliability, development speed, and long-term maintainability.
• Collaborate with engineers, product managers, data scientists, and operations teams to shape solutions and technical direction.
• Improve the reliability, observability, scalability, and operational excellence of the systems you own.
• Support and raise the engineering standards of the team through code reviews and knowledge sharing.
• Use AI-assisted development tools effectively while applying strong engineering judgment to validate output.

Skills

Backend design

Go/Kotlin

End-to-end ownership

Distributed systems

APIs & DBs

Observability

Data-heavy systems

Tools

Kafka

PostgreSQL

MongoDB

Redis

AWS

Kubernetes

Docker

gRPC

Job description

Wolt in Helsinki seeks a Senior Backend Engineer to own production systems, mainly using Go or Kotlin, and drive end-to-end technical initiatives.

You will design, build, and operate backend systems that support inventory, purchasing, and fulfillment, collaborating with product, data science, and operations teams to deliver scalable solutions.

Strong fundamentals in APIs, databases, and observability, plus comfort with data-heavy platforms like Kafka and Snowflake, are essential.