Backend Software Development Engineer; Fiat Job London England UK,Software Development

Position: Backend Software Development Engineer (Fiat Payments)
Location: Greater London

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
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
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
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, Cloud Watch); 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
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

Benefits

Team environment:
Transak operates on a hybrid work model, with team members across the world. We have a culture of trust and autonomy, with a focus on communication and collaboration
Career development:
At Transak, we believe that learning is a lifelong pursuit. We provide opportunities for our team members to learn and grow, with a focus on personal and professional development
Health & Wellness Benefits:
At transak, your wellbeing is our priority. Enjoy a comprehensive healthcare package, regular wellness programs, mental health support, flexible working hours, and work‑from‑home options
Work/life balance:
Non‑linear workdays are encouraged support our team members to take ownership of their time and schedule in a way that keeps them balanced in life and able to have the impact they want at work

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
Solid understanding of CI/CD pipelines, with hands‑on experience using Jenkins (pipeline-as-code, multi‑stage builds, automated test gates)
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
Track record of owning a…