Senior Software Engineer (Backend) – Fraud
Level inferred from job title
Job description
Senior Software Engineer (Backend) in BVNK's Fraud engineering team, building a fraud prevention capability from an early stage across fiat, crypto and card rails. The role designs and builds secure, scalable backend services and real-time risk decisioning systems.
At a glance
- Work mode
- Hybrid · Bulgaria · Spain · Poland
- Pay
- EUR 70,000 – 110,000 / year
What you'll do
- Design, build and maintain secure, scalable backend services and APIs that power fraud detection, risk decisioning and controls
- Build low-latency services that assess risk and approve, decline or challenge activity in real time, including card authorisations and payments
- 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
- 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
- Deliver the data pipelines, metrics and alerting that let the business measure fraud, tune rules and respond quickly to new attack patterns
- Work with data and ML colleagues to put machine learning models and AI-assisted workflows into production
- Work with Fraud Operations, Financial Crime, Cards, Payments and Data teams to deliver features end to end
- Contribute to architecture decisions, review code, mentor other engineers and help shape the engineering culture of a growing team
- Own your services in production, including monitoring, incident response and continuous improvement of reliability and performance
What we're looking for
- Strong, proven experience as a backend engineer building production systems, in Java with Spring Boot
- Hands-on experience with microservices and event-driven architectures, ideally with Kafka or similar messaging platforms
- Experience building systems where low latency, correctness, idempotency and auditability really matter
- Comfortable working with large volumes of event and transaction data, and with building pipelines that turn raw signals into decisions and insight
- Experience integrating with third-party APIs and webhooks, including handling failures, retries and data quality
- Experience with cloud platforms (preferably AWS), containerisation and CI/CD pipelines
- A solid grasp of secure coding practices and of handling sensitive data in regulated environments
- 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
- You use AI tools and agentic workflows to speed up delivery and improve quality
Nice to have
- Experience building fraud detection, transaction monitoring, risk scoring or account takeover prevention systems
- Experience with rules engines, or with putting ML models into production for real-time decisioning
- Experience with card authorisation flows, 3DS, chargebacks or payment rails such as Faster Payments, SEPA or ACH
- Experience with stablecoins, crypto or blockchain-based payments
Your team
Fraud engineering team
Small, autonomous squads that own their problem space; works closely with Fraud Operations, Financial Crime, Data, Product and other engineering teams.
Benefits
- 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
Apply
Direct apply at BVNK
Opens the job posting at BVNK
About BVNK
The stablecoin-powered financial stack for enterprises
BVNK enables businesses to build financial products, unlock new markets, and move money in seconds across 130+ countries, with 40+ licenses for fiat and digital assets globally. Processing billions annually, it empowers enterprises worldwide to send, receive, convert, and settle stablecoins and fiat seamlessly through a single integration. BVNK is now part of Mastercard.
Mission
To accelerate global money movement
Key facts
- Stablecoin-powered financial infrastructure / payments
- Part of Mastercard
- Enables money movement across 130+ countries
- 40+ licenses for fiat and digital assets globally
- Processing billions annually
- Team spread across EMEA, North America, and APAC
- Recognized by CNBC World's Top Fintech Companies (2026)
- FXC Intelligence Top 100 Cross-border Payment Companies (2026)
- Newsweek's The Top 100 Global Most Loved Workplaces (three years running, most recently 2025)
- LinkedIn Top 20 Startups in the UK (2025)
Partners & customers
What they value
- Strong opinions
- Simple solutions
- Moving fast in a sustainable way
- Diverse and inclusive