Senior Software Engineer (Backend) â?? Fraud

Senior Software Engineer (Backend) â?? Fraud Overview

The role

What you'll do

• Fraud platform development: Design, build and maintain secure, scalable backend services and APIs that power fraud detection, risk decisioning and controls.
• Real-time decisioning: Build low-latency services that assess risk and approve, decline or challenge activity in real time, including card authorisations and payments.
• Signal and data enrichment: Ingest and enrich device, session, behavioural and transaction data, and integrate it with third-party fraud and risk providers to build a full risk profile.
• Controls and friction: Build risk-based controls such as limits, velocity checks, blocks and step-up challenges (e.g. MFA or liveness) that stop fraud while keeping legitimate customers moving.
• Monitoring and alerting: Deliver the data pipelines, metrics and alerting that let the business measure fraud, tune rules and respond quickly to new attack patterns.
• ML and AI enablement: Work with data and ML colleagues to put machine learning models and AI-assisted workflows into production.
• Cross-domain collaboration: Work with Fraud Operations, Financial Crime, Cards, Payments and Data teams to deliver features end to end.
• Technical leadership: Contribute to architecture decisions, review code, mentor other engineers and help shape the engineering culture of a growing team.
• Operational excellence: Own your services in production, including monitoring, incident response and continuous improvement of reliability and performance.

What we need from you

• Backend expertise: Strong, proven experience as a backend engineer building production systems, in Java with Spring Boot.
• Distributed systems: Hands-on experience with microservices and event-driven architectures, ideally with Kafka or similar messaging platforms.
• Real-time, high-integrity systems: Experience building systems where low latency, correctness, idempotency and auditability really matter.
• Data-driven mindset: You’re comfortable working with large volumes of event and transaction data, and with building pipelines that turn raw signals into decisions and insight.
• Integration experience: Experience integrating with third-party APIs and webhooks, including handling failures, retries and data quality.
• Cloud and infrastructure: Experience with cloud platforms (preferably AWS), containerisation and CI/CD pipelines.
• Security awareness: A solid grasp of secure coding practices and of handling sensitive data in regulated environments.
• Ownership and communication: You take ownership of outcomes, communicate clearly with technical and non-technical stakeholders, and do well in a fast-moving environment where you’re building from scratch.
• AI-native mindset: You use AI tools and agentic workflows to speed up delivery and improve quality.
• Bonus: Fraud and risk domain: Experience building fraud detection, transaction monitoring, risk scoring or account takeover prevention systems.
• Bonus: Rules engines and ML: Experience with rules engines, or with putting ML models into production for real-time decisioning.
• Bonus: Cards and payments: Experience with card authorisation flows, 3DS, chargebacks or payment rails such as Faster Payments, SEPA or ACH.
• Bonus: Digital assets: Experience with stablecoins, crypto or blockchain-based payments.

What you can expect from us

• Fair and competitive salary at every stage of your growth
• Flexible working hours, with hybrid working at its heart
• A culture built on passionate, growth-minded people
• A flexible approach to holiday
• Opportunities to travel to our offices around the world
• An open and creative environment where you can help us define the future of BVNK, its culture, and its opportunity sets.

At BVNK, we are focused on building a diverse and inclusive team. While you may not meet all of our requirements, we’d encourage you to apply if you meet the majority of our expectations. You may be a great fit for this role or another role in our team.

Compensation packages are based on candidate experience and relevant certifications.

Bulgaria Salary Range

€70.000-€110.000 EUR

Spain Salary Range

€85.000-€110.000 EUR

Poland Salary Range

250 000 z?-480 000 z? PLN

Visa sponsorship: check with employer