Senior Backend Engineer (Go)

Kast
Kast

Software Engineering

Brazil

Posted on Aug 10, 2026
We're looking for a hands-on Senior Backend Engineer to help build and scale KAST's LATAM domestic payment rails.

You'll be a core contributor on the effort to onboard additional fiat payment providers as redundant, hot-swappable rails. You'll work closely with Product, Compliance/Risk, L3 production support, and provider partners to ship reliable, auditable payment systems that meet the LATAM Central Banks’ requirements.

Location: remote from Brazil.
Department
Engineering
Employment Type
Full Time
Location
Brazil
Workplace type
Fully remote

What You’ll Be Doing

  • Design and build production-grade backend microservices and APIs in Go
  • Implement resilient fallback and routing logic across providers (limits, uptime, KYC eligibility) with feature-flagged rollout and safe rollback paths
  • Partner with the fraud detection flow and onboarding/KYC integration to keep transaction and onboarding flows compliant and observable
  • Contribute to FSDs, technical design docs, and delivery estimates; break down work into forward-compatible increments and track open dependencies/pendencies
  • Design reliable, auditable, and secure systems with strong observability and operational workflows
  • Help raise the bar on backend engineering standards through code review, technical guidance, and mentorship of squad members

What You'll Bring

  • 5+ years of software engineering experience
  • Strong backend engineering expertise, particularly with Go
  • Experience building production-grade APIs and distributed systems, including event-driven / webhook-based integrations with third-party providers
  • Solid understanding of system reliability, security, and auditability, especially for money-movement or transactional systems
  • Ability to work through ambiguity: reverse-engineer existing flows, freeze interfaces early, and design for parallel delivery when dependencies aren't fully built yet
  • Comfortable working cross-functionally with product, compliance, operations, and external provider/partner teams
  • Startup mindset with strong ownership and execution ability
  • Experience with cloud infrastructure and modern engineering workflows (AWS, containers, relational databases, streaming/messaging)

Nice to have

  • Experience integrating payment providers / payment rails and reasoning about redundancy, provider failover, and reconciliation
  • Familiarity with PIX and the Brazilian payments landscape, including Central Bank regulatory requirements and named virtual accounts
  • Experience with KYC/KYB, AML, transaction monitoring, sanctions screening, or fraud/risk tooling
  • Experience in crypto, stablecoins, or Web3 infrastructure (e.g. BRL ↔ USDC / stablecoin conversion flows)
  • Experience decoupling tightly-coupled systems into provider-agnostic, adapter-based architectures
  • Spanish language skills to coordinate with local providers
  • Experience with AWS (ECS Fargate, Aurora/PostgreSQL), Kafka, Redis, Kubernetes, or Terraform

About KAST

KAST is redefining stablecoin banking for global citizens, crypto professionals, Web3-native businesses, and high-inflation markets hungry for USD-backed banking. Backed by top-tier global investors and led by the ex-APAC CEO of Circle, our leadership team spans Circle, Airwallex, Revolut, Wise, Grab, Zoom, AWS, and leading OTC desks. We’ve scaled from zero to nearly a million users at ridiculous speed.

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