Software Development Engineer III, Fiat Payments (Backend)

• 6+ years of professional software engineering experience, with a significant portion building backend/distributed systems; prior experience in fintech, payments, on-and-offramp provider, 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, 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, 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 - comfortable authoring design docs/RFCs and explaining trade-offs to engineers and non-technical stakeholders (Risk, Ops, external partners).

• 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.

Transak's Fiat/Payments team builds and operates the rails that move money between traditional banking systems and crypto - ACH, SEPA, Faster Payments, wires, virtual accounts, and card rails. 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 regulatory 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.

1. Payment Systems Ownership & 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.
2. Banking & 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, Compliance on KYC, AML, and fraud-control touchpoints in the payment flow.
3. Infrastructure, CI/CD & Operations
   • Build and maintain CI/CD pipelines (Jenkins) - 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.
4. Technical Leadership & Collaboration
   • Lead technical roadmaps - break down large, ambiguous payments initiatives into shippable milestones; write design docs/RFCs; drive consensus across Engineering, Product, Risk, and Operations.
   • Mentor and raise the bar - review code and designs, 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.