SDE III

As an SDE 3 you will own critical, high-throughput payment microservices end-to-end: design, build, scale, and operate systems that move real money for users across multiple currencies and jurisdictions, with US, UK/EU, and global banking-partner requirements as a core part of the job. This is a senior individual-contributor role calibrated against SDE 3 / Senior Engineer, driving architecture decisions, mentoring engineers, and being the go-to owner for a payments domain, while staying hands-on in code daily.

The core responsibilities for the job include the following:

Payment Systems Ownership and Architecture:

• Own payment microservices end-to-end design, build, deploy, and operate Node.js services (orders, payment, reconciliation, virtual accounts, payout orchestration) handling real-time financial transactions at scale.
• Design for correctness and failure: idempotent, retry-safe, reconciliable systems where every transaction is traceable, auditable, and recoverable (partial failures, webhook replays, duplicate detection, distributed state machines).
• Architect for scale and resilience across a distributed microservices architecture; make service-boundary and build-vs-buy decisions; address root causes rather than symptoms.

Banking and Partner Integrations:

• Drive integrations with banking and payment partners (e. g., banking and card providers/risk providers), API contracts, webhook handling, sandbox-to-production rollout, and reconciliation logic across multiple rails (ACH, SEPA, Faster Payments, wires).
• Work with Risk and Compliance on KYC, AML, and fraud-control touchpoints in the payment flow.

Infrastructure, CI/CD, and Operations:

• Build and maintain CI/CD pipelines (Jenkins) for automated testing, blue/green or canary deployments, and rollback strategies for services that cannot tolerate downtime or data loss.
• Operate infrastructure on AWS (ECS/EKS, Lambda, SQS/SNS, RDS, CloudWatch); contribute to infra-as-code, monitoring, alerting, and on-call runbooks for payment-critical systems.
• Optimize the data layer: schema design and query performance in MongoDB, caching and rate-limiting strategies with Redis, and safe migration patterns for high-volume transactional collections.
• Participate in on-call for payment-critical services, including incident response and postmortems.

Technical Leadership and Collaboration:

• Lead technical roadmaps; break down large, ambiguous payment initiatives into shippable milestones; write design docs/RFCs; drive consensus across engineering, product, risk, and operations.
• Mentor and raise the bar on code and design reviews, coach mid-level engineers, and help hire and grow the team.
• Uphold security and compliance best practices for handling PII/financial data in a regulated, PCI-DSS-adjacent environment.

Requirements:

• 5+ years of professional software engineering experience, with a significant portion building backend/distributed systems; prior experience in fintech, payments, on-and-offramp providers, or banking infrastructure strongly preferred.
• Strong hands-on expertise in Node.js (TypeScript preferred) for performant, production-grade backend services.
• Deep experience with MongoDB schema design, aggregation pipelines, indexing strategy, and performance tuning at scale.
• Proficiency with Redis caching, distributed locks, rate limiting, and pub/sub patterns.
• Proven experience designing and operating microservices architectures, including inter-service communication (REST/gRPC/event-driven via SQS/Kafka, ELK, New Relic, and Mixpanel), service discovery, and API contract design.
• Solid understanding of CI/CD pipelines, with hands-on experience using Jenkins (pipeline-as-code, multi-stage builds, automated test gates).
• Working knowledge of AWS infrastructure (ECS/EKS/Lambda), VPC networking basics, IAM, S3 RDS, and CloudWatch; infra-as-code (Terraform/CloudFormation) is a plus.
• Strong grasp of distributed systems fundamentals: idempotency, eventual consistency, retries/backoff, circuit breaking, and failure isolation.
• Track record of owning a service or domain end-to-end in production, including on-call responsibility.
• Excellent written communication and comfortable authoring design docs/RFCs and explaining trade-offs to engineers and non-technical stakeholders (Risk, Ops, external partners).

Nice-To-Haves:

• Experience with payment rails (ACH, SEPA, Faster Payments, SWIFT/wires) or card processing.
• Familiarity with banking partner integrations, webhook-driven reconciliation, or ledger/double-entry accounting systems.
• Exposure to KYC/AML/fraud tooling.
• Experience at a fintech/crypto-native company, payments processor, or Big Tech payments org.
• Prior experience operating in a regulated environment (FCA, EMI/PI licensing context), given the UK/EU banking scope of this role.