Senior Software Engineer (Backend) - Global Marts

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

Berlin, Germany; Helsinki, Finland; Stockholm, Sweden

About Wolt

At Wolt, we create technology that brings joy, simplicity and earnings to the neighborhoods of the world. In 2014 we started with delivery of restaurant food. Now we’re building the delivery of (almost) everything and you’ll find us in over 500 cities in 30 countries around the world. In 2022 we joined forces with DoorDash and together we keep on dreaming big and expanding across the globe. Working at Wolt isn’t always easy, but it’s definitely exciting. Here you’ll learn more, build more, and ship more than in most other companies. You’ll be challenged a lot, but also have a lot of fun on the way. So, if you’re a self-starter with drive and entrepreneurial spirit, this could be the ride of your life.

Who We Are

Global Marts builds the technology behind DoorDash's own grocery and retail operations across DashMart, Wolt Market, and Deliveroo Hop.

Our systems decide what products our stores stock, how much inventory to purchase, which vendors to source from, how warehouses execute orders, and what prices customers see.

We build everything from forecasting and replenishment systems to vendor management, warehouse execution, labor scheduling, space optimization, and pricing. Our in-house forecasting platform has replaced third-party solutions and now powers production globally.

This isn't a traditional CRUD backend environment. Much of our work involves designing new systems that solve complex operational problems at global scale.

What You'll Do

As a Senior Backend Engineer, you'll work primarily with Go or Kotlin and take end-to-end ownership of production systems and complex technical initiatives.

You’ll:

• 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 sometimes ambiguous business problems into pragmatic, scalable technical solutions.
• Make and influence architectural decisions, balancing scalability, reliability, development speed, and long-term maintainability.
• Collaborate closely 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 technical discussions, code reviews, and knowledge sharing.
• Use AI-assisted development tools effectively while applying strong engineering judgment to validate their output, improve development velocity, and identify opportunities where AI can create additional leverage.

How We Work

• Autonomy & Ownership: Engineers have end-to-end responsibility for their services, from design and implementation to production and on-call.
• Collaboration: Architecture and technical direction are shaped together. Senior engineers are expected to contribute actively to decisions and help others arrive at strong solutions.
• Scalability & Simplicity: We value pragmatic solutions that solve today's problems while providing a sustainable foundation for tomorrow.
• Impact: We work closely with Product, Data Science, and Operations, connecting technical decisions directly to real-world retail and operational outcomes.

Our primary backend languages are Go and Kotlin.

We also use Kafka, PostgreSQL, MongoDB, Redis, Snowflake, AWS, Kubernetes, Docker, gRPC, GitHub Actions, and modern cloud infrastructure.

You don't need experience with every technology in our stack. We're more interested in strong backend and distributed systems fundamentals and your ability to learn and make sound technical decisions.

We're looking for engineers who:

• Have strong experience designing, building, and operating production backend systems.
• Have professional experience with Go, Kotlin, or another modern backend language.
• Have experience owning services end-to-end, including design, implementation, deployment, monitoring, reliability, and production operations.
• Have strong knowledge of backend and distributed systems fundamentals, including APIs, databases, asynchronous processing, failure handling, testing, and observability.
• Are comfortable working with data-heavy systems and technologies such as Kafka, Snowflake, or similar streaming and data infrastructure.
• Can navigate ambiguous problems, break them into actionable steps, make appropriate technical trade-offs, and deliver incrementally.
• Can influence technical decisions beyond their immediate tasks and collaborate effectively with engineers and cross-functional partners.
• Communicate technical concepts and decisions clearly and concisely.
• Use AI-assisted development tools effectively in their everyday engineering workflow while critically evaluating generated solutions and taking full ownership of the resulting code and technical decisions.
• Look for opportunities to use AI to improve engineering productivity and solve problems more effectively, while understanding where human engineering judgment remains essential.

Nice to Have

Experience in one or more of the following is a plus:

• Grocery, retail, logistics, supply chain, or warehouse technology.
• ERP, vendor management, procurement, or workforce management integrations.
• Replacing third-party or legacy platforms with internally built systems.
• High-throughput event-driven or streaming architectures.

Why Join Us?

You’ll help build the technology that powers DoorDash’s global grocery and retail business, solving complex operational challenges across inventory, forecasting, fulfillment, pricing, and supply chain.

You’ll have significant ownership over the systems you build and the opportunity to influence technical direction while working closely with experienced engineers, product managers, data scientists, and operations teams across multiple markets.

Our Commitment to Diversity and Inclusion

We’re committed to growing and empowering a more inclusive community within our company, industry, and cities. That’s why we hire and cultivate diverse teams of people from all backgrounds, experiences, and perspectives. We believe that true innovation happens when everyone has room at the table and the tools, resources, and opportunity to excel.