Blockchain Payments Engineer

Lead Blockchain Payments Engineer - Fiat Ramps & Financial Infrastructure

Location: Full-time, In-person — London, UK

Compensation: $250K - $300K

Join a team of elite builders and a high-growth software company redefining what is possible in the fintech and crypto space. We operate with a philosophy of speed, ownership, and talent density, driving towards a future where financial flows are seamless and instantaneous.

As the Lead Blockchain Payments Engineer, you will be a core architect and owner of our essential financial infrastructure. This high-impact role requires you to design and scale the core services that power seamless fiat ↔ crypto flows, real-time risk decisions, and rock-solid financial records for a high-volume, global platform.

You will act as a backend and onramp specialist, leading the development of high-throughput, low-latency distributed systems that manage the entire financial lifecycle from user deposit to on-chain settlement.

Payment Orchestration & Integrations

• Own the end-to-end payment orchestration for major bank rails (ACH/RTP/FedNow/SEPA/Open Banking) and card schemes (including Apple Pay/Google Pay).
• Design and implement idempotent, fault-tolerant APIs and robust webhook processing systems.
• Integrate and manage third-party providers for connectivity (Plaid/TrueLayer/Tink), card processing (Stripe/Checkout.com/Adyen), and on-chain risk/compliance (Chainalysis/TRM, Travel Rule networks).

Real-Time Risk & Compliance

• Build and scale a real-time risk engine ($\le 300$ms) combining ML scores, rules, device signals, sanctions/KYC hits, and payment intelligence to yield fast GREEN/AMBER/RED outcomes.
• Implement foundational KYC/AML primitives (CIP/CDD, sanctions/PEP screening, Travel Rule data plumbing) in close partnership with the Compliance team, ensuring audit-ready decision journaling.

Financial Integrity & Reconciliation

• Ship a double-entry ledger and automated reconciliation jobs that accurately tie together processors, bank statements, and on-chain balances.
• Develop daily break detection and automated remediation workflows to maintain absolute financial integrity.

Blockchain & Operations

• Ensure safe and rapid crypto delivery (e.g., USDC/SOL) to user wallets by managing hot-wallet flows, transaction creation, confirmations, and operational safeguards.
• Instrument everything with traces, metrics, and logs. Build internal operations and compliance dashboards and participate in the production on-call rotation for our 24/7 system.

Cross-Functional Collaboration

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

Requirements

• Fiat Onramp Expertise: Proven experience building fiat ramps end-to-end, including bank and card integrations.

• System Design & Scale: Deep experience designing and scaling high-throughput, low-latency distributed systems in payments, fintech, or risk platforms.
• Language Fluency: Fluent in one or more systems languages (Rust, Go), or strong systems chops in TypeScript/Node/Python.
• Database Mastery: Expert-level knowledge of Postgres (transactions, indexing, locking), with familiarity in Redis and event/OLAP stores (Kafka/Redpanda, ClickHouse).
• API & Webhook Craftsmanship: Mastery of gRPC/REST best practices (versioning, idempotency keys) and building rock-solid webhook consumers.
• Event-Driven Design: Experience designing systems with queues, outbox/inbox patterns, Sagas, and ensuring exactly-once-effective behavior for financial transactions.
• Security Mindset: Practical experience with key management (HSM/KMS), secrets hygiene, least privilege, and data auditability.
• Ownership & Ambiguity: Ownership-driven and comfortable operating in high-ambiguity environments—you move quickly, measure results, and iterate aggressively.

Nice to Have (Signal Boosters)

• Payments: ACH/NACHA returns, 3DS/SCA, AVS/CVV, BIN analysis, chargeback workflows, Apple/Google Pay.
• Compliance Plumbing: Experience with sanctions/PEP screening, Travel Rule networks (e.g., Notabene/TRISA), and SAR/STR workflow integration.
• Accounting: Experience with double-entry ledgers, reconciliation jobs, and data modeling for regulatory/tax reporting.
• Crypto Delivery: Solana RPCs, USDC flows, wallet operations, and Chainalysis/TRM integrations.
• Infra: Experience with AWS, Terraform, Docker/Kubernetes, and OpenTelemetry/Prometheus/Grafana.

Benefits

• Compensation: Competitive Base Salary

• Incentives: Token/Equity package for long-term alignment.
• Culture: High-impact role in a company driven by speed, ownership, and talent density.
• Location: Full-time, in-person role in London.

Due to the high volume of applications we anticipate, we regret that we are unable to provide individual feedback to all candidates. If you do not hear back from us within 4 weeks of your application, please assume that you have not been successful on this occasion. We genuinely appreciate your interest and wish you the best in your job search.

Commitment to Equality and Accessibility:

At MLabs, we are committed to offer equal opportunities to all candidates. We ensure no discrimination, accessible job adverts, and providing information in accessible formats. Our goal is to foster a diverse, inclusive workplace with equal opportunities for all. If you need any reasonable adjustments during any part of the hiring process or you would like to see the job-advert in an accessible format please let us know at the earliest opportunity by emailing [email protected].

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