Blockchain Payments Engineer

As a Lead Blockchain Payments Engineer at MLabs, you serve as a core architect of the firm's financial infrastructure. You design and scale the services powering seamless fiat-to-crypto flows, real-time risk decisioning, and immutable financial records. Based in London in a full-time, in-person role, you thrive in high-throughput, low-latency environments and are passionate about building the future of global value transfer.

What you'll do

• 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)
• Build and scale a real-time risk engine targeting latencies of 300ms or less, 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
• 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
• Manage hot-wallet flows, transaction creation, and operational safeguards to ensure safe, rapid delivery of crypto assets such as USDC and SOL
• 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
• Work closely with Product, Mobile, Compliance, Risk, and Finance teams to drive features from initial concept through production deployment and iteration

What you bring

• Proven experience building fiat ramps end-to-end, including bank and card integrations
• Deep experience designing and scaling high-throughput, low-latency distributed systems in payments, fintech, or risk platforms
• Fluency in one or more systems languages (Rust, Go), or strong systems expertise in TypeScript, Node, or Python
• Expert-level knowledge of Postgres including transactions, indexing, and locking, with familiarity in Redis and event/OLAP stores (Kafka/Redpanda, ClickHouse)
• Mastery of gRPC and REST best practices including versioning and idempotency keys, and the ability to build rock-solid webhook consumers
• Experience designing systems with queues, outbox/inbox patterns, Sagas, and ensuring exactly-once-effective behavior for financial transactions
• Practical experience with key management (HSM/KMS), secrets hygiene, least privilege, and data auditability
• Ownership-driven mindset and comfort operating in high-ambiguity environments, moving quickly, measuring results, and iterating aggressively

Nice to have

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

What we offer

• High-impact ownership, with every team member empowered to make significant architectural and business decisions
• Work alongside an elite group of engineers and builders in a high-performance environment
• Direct exposure to a modern stack including Rust, Go, Kafka, and AWS (EKS, RDS, KMS)
• An environment that values shipping and iteration over bureaucracy and perfectionism
• Competitive compensation including base salary plus equity and tokens

About MLabs

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