Backend Engineer

Zaver; Stockholms kommun; On-site; SEK 900,000 - 1,200,000; Full time

Job summary

Zaver is building a core payments platform using a Java/Spring Boot monolith that processes checkout flows, real-time credit decisions, and multi-currency accounting across European markets. You will help ensure reliability, accuracy, and performance in production systems handling real money across borders.

We value engineers who can think about systems, anticipate failure modes, and ask what happens when a feature goes wrong.

Qualifications

• Must think in terms of edge cases and failure modes.
• Experience with payments or financial systems is a plus.
• Strong problem-solving and systems thinking mindset.

Skills

Java

Spring Boot

Systems thinking

PostgreSQL

SQL

Tools

Spring ecosystem tooling

Job description

The tech

You won’t be gluing COBOL together. Our core platform is a Java/Spring Boot monolith - deliberately so - that handles checkout flows, real-time credit decisions, bank clearing, AML compliance, multi-currency accounting, and direct integrations with European banks and payment providers.

Every line of code you write has consequences. It moves money. It approves or denies credit. It talks to regulators. This is engineering where the edge cases aren’t theoretical - they’re someone’s car purchase failing at 2pm on a Sunday.

What we’re really looking for

Here’s the thing. AI can generate code now. That’s not a secret. What it can’t do - what it won’t do for a long time - is think about systems. Anticipate the failure mode nobody asked about. See the race condition hiding behind a perfectly reasonable-looking feature request. We need people who look at a spec and immediately start asking “what happens when...” We don’t care about your years of experience. We care about how you think. If that sounds like you, let’s talk.

Bonus:

• Strong SQL and PostgreSQL instincts
• An obsession with edge cases, failure modes, and the question “what could go wrong here?”
• The ability to hold a large, complex system in your head and reason about it

Why Zaver

World’s most efficient guerilla group - tight team, real problems. No middle management. The best ideas win. You’ll work directly on infrastructure that handles real money in different countries, and you’ll see your decisions play out in production.

We’re building something that matters, with people who care about getting it right. Let’s challenge legacy solutions together and make some waves within payments