Senior Software Engineer (Backend)

Zevoy group; Helsinki; On-site; EUR 100,000 - 134,000; Full time

Benefits offered by this job

Brand-new Helsinki office desk (Erottä

Job summary

Zevoy is seeking a Senior Backend Engineer to own mission-critical backend systems that move real money for thousands of European businesses. Based in Helsinki, you’ll design, build and harden services beneath APIs used by frontend and mobile teams, with a strong focus on reliability and scale.

You’ll work on end-to-end ownership of integrations with accounting and banking systems, across REST/OAuth2 and legacy data flows, as the company expands into new markets. Helsinki office, 3 days on-site.

Qualifications

• 5+ years of backend engineering experience.
• Strong Go (or similar statically-typed language) and SQL fundamentals.
• Ownership of production systems end-to-end.
• Experience integrating with third-party systems, preferably financial data.
• Comfort with event-driven, cloud-native infrastructure (AWS; Azure/GCP ok).
• AI-augmented workflow usage and tooling.
• Product-minded ownership ensuring secure, scalable delivery.
• Excellent spoken and written English.
• Willingness to work on-site 3 days/week; no relocation or visa sponsorship.

Responsibilities

• Own backend features from architecture design through deployment and production monitoring.
• Develop, maintain, and scale core accounting and banking integrations (REST/OAuth2, legacy SFTP/SOAP/XML/CSV).
• Lead technical work to build integrations for new markets across Europe.
• Slice complex projects into high-value increments with business owners.
• Balance velocity with system health, improving tests, observability, and debt reduction.

Skills

Backend experience

Go

SQL

Ownership

3rd-party integrations

Event-driven

AWS

Azure/GCP

AI tooling

Product mindset

English fluency

On-site work

Tools

Go

REST/OAuth2

Job description

On-site: 3 days/week — this role is based out of our Helsinki office and is only open to candidates with an existing right to work in Finland. We are not able to offer relocation support or visa sponsorship for this position.

Reports to: CPO

About Zevoy

We are a fast-growing, regulated fintech (EMI) reshaping corporate expense management. We process real-time transaction data across 13 European markets, turning the chaos of corporate spending, receipts, and accounting into a seamless, automated flow. Our platform combines smart Visa payment cards, an intuitive mobile app, and a robust backend that integrates deeply with European banking and accounting systems. We are one of Finland's top 100 fastest-growing companies because we build pragmatic, high-quality tech that solves real pain points for our users.

Why this role matters

Our ability to integrate flawlessly with our clients' accounting and banking systems is one of the biggest levers we have for growth. Every new integration you build or harden can unlock an entire wave of clients in a market we couldn't previously serve well — you'll be the engineer who makes that expansion technically possible.

The Role

We are looking for a Senior Backend Engineer to take ownership of the systems that move real money for thousands of businesses across Europe. In a world where the "how" of writing code is increasingly accelerated by AI, your greatest asset is understanding the "why" — the business domain, the failure modes, and the architectural tradeoffs that matter when you're handling financial data at scale.

This is a backend-first role. You'll work closely with frontend and mobile engineers who consume your APIs, but your core job is designing, building, and hardening the services underneath — not shipping UI.

Key Responsibilities

• End-to-End System Ownership: Drive backend features from architecture design through deployment and production monitoring. You care about how your code behaves under real transaction load, not just locally.
• Deep Integration Ownership: Take full accountability for developing, maintaining, and scaling our core accounting and banking integrations — from modern REST/OAuth2 APIs to legacy SFTP/SOAP/XML/CSV data flows.
• New Market Entry: As we expand geographically across Europe, lead the technical work of building the integrations that make each new market possible.
• Pragmatic Problem Solving: You know that understanding the problem is 80% of the work. You're comfortable working directly with business owners to slice complex projects into shippable, high-value increments.
• Balance Velocity with System Health: You maintain standards while shipping — paying down technical debt, hardening test coverage, and keeping observability sharp (metrics, tracing, alerting).

Our stack

Go, GraphQL and REST APIs, event-driven serverless infrastructure on AWS (EventBridge, Lambda), with daily deployments and a modern CI/CD pipeline. Equivalent experience on Azure or GCP transfers directly.

What You Bring

Must-Haves:

• 5+ years of professional backend engineering experience, with strong command of Go (or a comparable statically-typed backend language) and solid SQL/relational database fundamentals.
• A track record of owning production systems end-to-end — design, deployment, incident response, and the operational maturity that comes with it.
• Hands-on experience integrating with third-party systems, ideally involving financial or accounting data — this is core to what we build, not a side skill.
• Comfort with event-driven, cloud-native infrastructure. We run on serverless architecture on AWS. Equivalent experience on Azure or GCP transfers directly.
• An AI-augmented workflow. You already use tools like Cursor or similar to multiply your output, and you understand AI handles the boilerplate while you own the architecture and the prompt context.
• Product-minded ownership. You don't just close tickets — you validate that what you ship is secure, scalable, and actually solves the problem.
• Excellent spoken and written English.
• Able to commit to on-site work 3 days/week. We cannot support relocation or visa sponsorship for this role.

Nice-to-Haves:

• Frontend exposure (React, TypeScript, GraphQL) — useful but not required for this role.
• Previous experience in expense management, payments, or fintech more broadly.
• Experience in startup or scale-up environments.
• Third-party integration experience spanning both modern APIs (REST/OAuth2) and legacy data transfer patterns (SFTP, SOAP, XML/CSV parsing).
• Familiarity with financial data patterns — double-entry bookkeeping, localized VAT/tax rules, or standardized payment file generation (e.g. SEPA).

What We Offer

• Direct, High-Scale Impact: Your code directly simplifies the financial workflows of thousands of users across 13 European markets. We value shipping real, pragmatic solutions over endless meetings.
• Transparent Compensation & Top-Tier Gear: A competitive monthly salary based on experience, plus the hardware and premium AI tooling you need to do your best work.
• Entrepreneurial Culture: An informal, professional, international team that supports autonomous decision-making.
• Prime Location & Team Connection: A dedicated desk at our brand-new office in Erottaja, Helsinki.