Senior Software Engineer (Backend) – Fraud

About us:

BVNK is the stablecoin-powered financial stack for enterprises. We're now part of Mastercard, and together we're building a network for every form of money – one that delivers more reach, more capability and more choice.

We enable 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, we empower enterprises worldwide to send, receive, convert, and settle stablecoins and fiat seamlessly through a single integration.

Our mission is to accelerate global money movement, and we're assembling a world-class team to make it happen.

Trusted by industry leaders like Corpay, Worldpay, Deel, and Flywire, we deliver the infrastructure that makes new forms of money usable within the financial systems customers already rely on today.

By combining Mastercard's global payment reach and trusted networks with BVNK's stablecoin infrastructure, we're building the trusted operating layer for the evolution of money movement, helping customers participate in emerging digital networks without having to rebuild their businesses around every new innovation.

We're a diverse team spread across EMEA, North America, and APAC, with a shared belief that stablecoins are the new infrastructure layer for financial services, and that BVNK is at the forefront of this shift.

We're incredibly honored to have been 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 as one of the Top 20 Startups in the UK (2025)

Location: We offer a Hybrid/Remote working policy. 

FUNCTION: Engineering

We're looking for a Senior Software Engineer (Backend) to join our Fraud engineering team. This is a chance to help build a fraud prevention capability from an early stage, at a company moving money across fiat, crypto and card rails at global scale.

You'll design and build the backend systems that detect and prevent fraud across the whole customer journey: onboarding, login and account activity, payments and card transactions. That means bringing device, behavioural and transaction signals together, powering real-time risk decisions, and giving our Fraud Operations team the data and tools they need to act quickly. Over time, this capability will also protect the businesses that build on BVNK.

You'll work closely with Fraud Operations, Financial Crime, Data, Product and other engineering teams. We work in small, autonomous squads that own their problem space. We value strong opinions, simple solutions and moving fast in a sustainable way.

Key Areas of Responsibilities:

• 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.