Location: London

On-site | Full-time

Compensation: Competitive

Our client is an elite team of builders operating at the intersection of fintech and high-scale crypto infrastructure. As a high-growth software organization, the company is responsible for developing the technology behind some of the largest crypto social networks and digital asset launchpads globally. The organization is defined by a philosophy of extreme talent density, rapid iteration, and technical ownership.

The Lead Blockchain Payments Engineer (Fiat Ramps) will serve as a core architect of the firm's financial infrastructure. This role is responsible for designing and scaling the services that power seamless fiat-to-crypto flows, real-time risk decisioning, and immutable financial records. Based in London, this is a full-time, in-person position for an engineer who thrives in high-throughput, low-latency environments and is passionate about building the future of global value transfer.

Key Responsibilities

Payment Orchestration & Integrations

• Own end-to-end orchestration for major bank rails (ACH, RTP, FedNow, SEPA, Open Banking) and card networks (Apple Pay, Google Pay).
• Design and implement idempotent, fault-tolerant APIs and robust webhook processing systems.
• Manage third-party provider integrations for connectivity (Plaid, TrueLayer), processing (Stripe, Adyen), and on-chain compliance (Chainalysis, TRM).

Real-Time Risk & Compliance

• Build and scale a real-time risk engine targeting latencies of $\le 300$ms, incorporating ML scores, device signals, and blockchain analytics.
• Implement foundational KYC/AML primitives and Travel Rule data plumbing in collaboration with the Compliance team to ensure audit-ready journaling.

Financial Integrity & Reconciliation

• Architect a double-entry ledger and automated reconciliation jobs to synchronize processors, bank statements, and on-chain balances.
• Develop automated break detection and remediation workflows to maintain absolute financial integrity.

Blockchain & Wallet Operations

• Manage hot-wallet flows, transaction creation, and operational safeguards to ensure safe, rapid delivery of crypto assets (e.g., USDC, SOL).

Reliability & Instrumentation

• Establish high standards for reliability using circuit breakers, dead-letter queues, shadow traffic, and canary releases.
• Instrument all high-risk financial flows with comprehensive traces, metrics, and logs using OpenTelemetry and Grafana.

Cross-Functional Collaboration

• Work closely with Product, Mobile, Compliance, Risk, and Finance teams to drive features from initial concept through production deployment and iteration.

Requirements

• Fiat Onramp Expertise: Proven track record of building fiat-to-crypto ramps from the ground up.
• System Design & Scale: Extensive experience in high-throughput, low-latency distributed systems, payments, or fintech risk platforms.
• Language Fluency: Professional proficiency in systems languages such as Rust or Go; alternatively, strong systems-level experience in TypeScript, Node.js, or Python.
• Database Mastery: Expert-level knowledge of Postgres (transactions, indexing, locking), Redis, and event/OLAP stores (Kafka, ClickHouse).
• API Craftsmanship: Mastery of gRPC/REST best practices, including versioning, idempotency keys, and secure authentication/authorization patterns.
• Event-Driven Design: Experience with queues, outbox/inbox patterns, and Sagas to ensure exactly-once-effective behavior.
• Security Mindset: Practical experience with KMS/HSM usage, secrets hygiene, and the principle of least privilege.

Preferred Signal Boosters

• Familiarity with ACH/NACHA returns, 3DS/SCA, and chargeback workflows.
• Experience with Open Banking transfer initiation (Plaid, TrueLayer, Tink).
• Knowledge of Solana RPCs and wallet operations.
• Experience in accounting data modeling for regulatory/tax reporting (1099-DA/DAC8).
• Hands-on experience with AWS (EKS, RDS, KMS), Terraform, Docker, Kubernetes, and CI/CD pipelines.

Benefits

• High-Impact Ownership: Every team member is empowered to make significant architectural and business decisions.
• Talent Density: Work alongside an elite group of engineers and builders in a high-performance environment.
• Cutting-Edge Tech: Direct exposure to a modern stack including Rust, Go, Kafka, and AWS (EKS, RDS, KMS).
• Speed & Autonomy: An environment that values shipping and iteration over bureaucracy and perfectionism.
• Competitive Package: A high-tier compensation structure including Base Salary plus Equity/Tokens.

Interview Process

1. Recruiter / HR Call: Initial screening and background alignment.
2. Technical Interview I: Deep dive into backend architecture and payment logic.
3. Technical Interview II: Advanced systems design and live problem-solving.
4. Final Interview: Comprehensive wrap-up with the leadership team focused on mission alignment and expectations.