Senior / Staff Software Engineer (New Product) - Greenstep Espoo

Greenstep; Espoo; Hybrid; EUR 100,000 - 160,000; Full time

Benefits offered by this job

Together bonus

Flex benefit

Lunch discount

Job summary

Greenstep in Espoo is hiring a hands-on Staff Software Engineer to own system architecture for a new multi-tenant SaaS product. You will work across Go core, Python layer, and front-end with React, ensuring correctness, documentation, and auditable changes.

The role emphasizes architecture influence, high standards, and collaboration within a small, senior team. The position is hybrid, with at least 50% in the office.

Qualifications

• 10+ years building production backend systems, including several years operating them.
• Distributed systems in depth with networked services and fault tolerance.
• Multi-tenant SaaS design with tenant isolation and data residency concerns.
• Deep Postgres design, indexing, transactions and isolation levels.
• Postgres at scale, partitions, read replicas, and sharding concepts.
• Strong TypeScript or Python skills; Go is a plus.

Responsibilities

• Own the architecture of the system and define boundaries between services.
• Design and build end-to-end services across Go core and Python layer.
• Own multi-tenancy model and data residency considerations.
• Shape the product architecture with a senior, evidenced approach.
• Review peers' work and document decisions with clear writings.

Skills

Distributed systems

Go

Python

TypeScript

PostgreSQL

Kubernetes

AI coding tools

Software architecture

Multi-tenant SaaS

Testing & QA

Tools

React

CI/CD

SQL

Job description

Do you want to build something new from the first commit, with people who hold the bar as high as you do? We are a small senior team building a new product that has not been announced yet, and we are looking for one more engineer at the same level.

Greenstep is a Finnish, family-owned growth company founded in 2010 that provides high-quality technology and back-office services to support its clients' growth and success. Today we are a community of more than 800 experts working in the Nordics and across Europe. We have grown organically, and today Greenstep has people in Finland, Åland, Sweden, Norway, Estonia, Denmark and the Netherlands. We share one goal: to help growth companies become leaders in their fields.

Alongside our services we build our own software. BI Book already serves thousands of clients in several countries, Bezala 100t+ active users and several other good success stories. Now we are building our next product, and we are hiring the people who will build it.

The Role

You join a small team building a new multi-tenant SaaS product from day zero. We cannot say much publicly yet. We will tell you everything in the first conversation. What we can say now:

• The stack is modern and deliberate. Go for the deterministic core, Python for AI and reporting services, React and TypeScript on the front end, Postgres with row-level security underneath, and an event-driven architecture.
• We are spec driven. Every feature gets a product spec and a build spec before code. Schema changes ship with documentation. Decisions become architecture decision records.
• Correctness is non-negotiable. The product works in a domain where every change must be exact and auditable. Tests and reviews are not optional.
• AI is part of the workflow. You will use AI coding agents every day and hold their output to the same standard as any other code. As a Staff Software Engineer you will:
• You will own the architecture of the system, not just the services in it. You set the boundaries between services, the contracts between them, and the failure model that holds when one of them is down.
• You’ll design and build services end to end, from schema to API to tests to production, across the Go core and the Python layer. This is a hands-on role and stays hands-on.
• You will own the multi-tenancy model. Tenant isolation, data residency, noisy-neighbour behaviour and the blast radius of any single tenant are your call, and you make that call explicit in writing.
• Own the data layer's long game. Schema design, partitioning strategy, and a defensible answer to when the system needs to scale horizontally and what it costs when it does.
• Own how the system runs. Kubernetes topology, resource and scaling behaviour, rollout and rollback strategy, and the observability that makes an incident diagnosable in minutes rather than hours.
• Turn specs into working software and push back on the specs when they are wrong.
• Raise the bar for everyone. You review other people's work, write the decision records the team argues with, and make the engineers around you better. At this level your impact is measured through the team, not only through your own commits.
• Shape the product. In a team this size your view on architecture and direction carries real weight.

Greenstep works in a hybrid model: at least 50% of working time is at the office.

What We're Looking For

You are a hands-on staff engineer who has owned a distributed production system from design to operation, carried the pager for it, and lived with the consequences of your own architecture decisions. You want to do it again on a clean slate. You are precise about details, you see the whole system, and you can explain your reasoning in writing well enough to change other people's minds.

What we expect you to bring:

• 10+ years building production backend systems, including several years operating them, not only shipping them.
• Distributed systems in depth. You have designed and run services that communicate across a network and you are fluent in what that costs: partial failure, retries and idempotency, ordering and exactly-once claims, consistency trade-offs, and backpressure. You can explain a real outage you caused or fixed and what you changed afterwards.
• Multi-tenant SaaS in depth. You have designed a tenant isolation model and lived with it. You have clear opinions on shared-schema versus schema-per-tenant versus database-per-tenant, how tenant context is carried and enforced end to end, and how you keep one tenant from degrading everyone else.
• Deep Postgres. Schema design, indexing, query planning, transactions and isolation levels, connection pooling, locking and long-running migrations on live tables. Row-level security for tenant isolation is a strong plus.
• Postgres at scale. Declarative partitioning and a worked understanding of horizontal scaling: read replicas, logical replication, tenant placement and rebalancing, cross-shard queries and the operations they break. What matters most to us is the judgment: knowing when a system genuinely needs to shard, what it costs once it does, and how to keep that door open without walking through it too early. Hands-on experience running a sharded or Citus-style fleet is a significant plus, not a hard requirement.
• Strong TypeScript or Python, and comfort working in both. Go is a plus.
• Event-driven or event-sourced systems, or a clear understanding of why they are hard to get right.
• A high standard for correctness and testing. You have worked where a bug is a compliance issue, not just a ticket.
• Daily, deliberate use of AI coding tools, and your own opinions about where they fail.
• Clear written communication. Specs, decision records and pull request descriptions are part of the job, and at this level they are how most of your influence travels.
• Genuine curiosity about the business domain. You want to understand what users do, not just what the ticket says.
• The working language is English. Finnish is not required.

You join Greenstep's product and technology organisation. More than 60 data, analytics and AI specialists work across three countries, alongside the BI Book product team and Greenstep's internal development teams. The new product team is small and senior by design. Its first users are Greenstep's own experts, so you get honest feedback from people who use what you build every day.

Why Greenstep?

Greenstep Oy is a family company founded in 2010 that provides high-quality services to support its clients' business and growth. Every Greenstepper matters to us, and alongside interesting work we want to offer excellent employment for everyone. You join a community where expertise, responsibility and caring for each other show in everyday work. Across Greenstep we are already a network of more than 800 experts. Together we move forward while building our own professional expertise.

Support for your well-being. For us, everyone's well-being and well-being at work are top priorities. Our occupational health is comprehensive, and our offices are ergonomically designed. The Flex benefit and lunch discount offered through Epassi are available to you. However, the number one thing that supports your well-being at work is a sustainably built resource budget.

A salary model that matches your responsibilities and experience. All Greenstep employees are also included in our Together bonus, through which we share 10% of the annual operating profit among all employees, regardless of role.

Support and time for development and strengthening your skills. At Greenstep, continuous learning is at the core of what we do. Our own Greenstep Academy offers training in various topics almost weekly!

Career opportunities in a growing family-owned company. We grow organically primarily with a few small exceptions where the culture has been 100% on par with ours. Because, we want to grow in a controlled manner, profitably and without compromising on quality. For us, growth means new opportunities: we can make a more positive impact on society, create new jobs, invest in the development and skills of our personnel, and enable business continuity. Our culture has developed together over the years, and our values are reflected in our everyday work.

This role is located in our Espoo office. With our hybrid work model, we are at least 50% of the work time at the office with our colleagues! Please note that Greenstep doesn't sponsor work visas, so to work with us, you need to hold a full-time work permit and live close to mentioned location.