Job Description

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.

Key responsibilities

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