Back End Developer

🔵 Freelance Backend Developer | Java / Spring | €350 per day | Fully Remote

I’m looking for an experienced Backend Developer to support a growing European fintech while they build out their permanent team.

You’ll join a small, hands-on development team working on a payments platform used by thousands of businesses. This needs someone who can take ownership from design through to production, with a real understanding of what happens when transactions fail, retry or arrive twice.

What you’ll work on:

• Building reliable payment processing services

• Developing APIs and integrations with banks and software partners

• Improving PostgreSQL queries, data models and processing performance

• Investigating production issues and putting lasting fixes in place

What you’ll need:

• Strong commercial Java and Spring experience

• Solid SQL/PostgreSQL knowledge, including transactions and indexing

• Experience with concurrency, retries and preventing duplicate processing

• Confidence owning production services and explaining technical trade-offs

• Fluent English

Go and payments/fintech experience would be a bonus.

💶 €350/day — freelancer rate

🌍 Fully remote — based within one hour of Central European time

🕒 No developer on-call requirement

Interested and available for an interim assignment? Send me your CV and earliest availability, or drop me a message for a chat.