Backend Engineer

About Monida

Monida is AI-native cross-border payments infrastructure built for cash-to-digital remittances in high-volume migrant corridors. Our customers are migrants in the U.S. sending money home to Mexico, Guatemala, and other countries every month, in cash, at retail locations they already trust, like 7-Eleven and Walmart. We turn that cash into a compliant, near-instant digital payout on the other end.

The Role

We're hiring a Backend Engineer to build and scale MonidaOS Core. You'll report to our CTO and work alongside him on the core backend. This is real infrastructure we're actively building out, not a mature, fully-staffed engineering org. You'll own meaningful pieces of the transaction pipeline directly, and your decisions will show up immediately in the mobile app our customers use to send money.

What You'll Do

· Money movement. Build and maintain core transaction logic, FX conversion, fee calculation, settlement, refunds, and reversals, on a double-entry ledger with optimistic concurrency control. Every write must be idempotent and safe to retry.

· Payment rail integrations. Integrate and maintain third-party partner APIs across ACH, debit card, cash-in retail networks, and cross-border payout providers (bank deposit and cash pickup), including signed webhooks, status polling, retries, and failure handling.

· Reconciliation. Build the jobs and tooling that match our ledger against partner and bank settlement files, and surface exceptions to Operations and Finance.

· Mobile-first APIs. Design versioned REST/JSON APIs for our Flutter app and web client, token auth and refresh, tolerance for flaky connections, backward compatibility across app releases.

· Security. Implement and harden authentication (OTP/MFA, device binding and recovery), rate limiting, encryption of sensitive data, and immutable audit logging.

· Compliance in code. Wire KYC, sanctions (OFAC) screening, transaction limits, and fraud rules into the transaction flow, and support the Compliance team with the data and admin tooling they need.

· Quality and production. Write tests, review code, document APIs, and share production support — including an on-call rotation, for a live system that moves real money.

What You Need

· 3+ years of professional backend development with PHP and Laravel.

· Hands-on experience building money-movement or transactional systems where correctness matters: ledgers or double-entry accounting, idempotency keys, database transactions, locking/concurrency control, and handling duplicate or out-of-order events.

· Proven experience integrating third-party payment, banking, or fintech APIs, including verifying signed webhooks (HMAC), handling retries and timeouts, and reconciling your records against theirs.

· Proven experience building and versioning REST APIs consumed by a mobile client (Flutter, React Native, or native iOS/Android), not only internal or web-only APIs. Be ready to talk through real trade-offs: payload size, sessions on unreliable networks, backward compatibility across app versions.

· Strong SQL and relational database skills (MySQL/MariaDB), including query optimization, replication, and schema migrations on live data.

· Experience with Redis and queue-based/async processing (Laravel Horizon or an equivalent like Sidekiq or Celery).

· Solid application security fundamentals: token-based auth, MFA, rate limiting, secrets management, encryption at rest and in transit, and the OWASP Top 10.

· Comfortable with Docker, CI/CD pipelines, and cloud infrastructure, plus logging and monitoring in production.

· Daily, productive use of AI coding tools (e.g., Claude, Copilot, Cursor), with the judgment to review and test what they produce.

· Professional-level English and Spanish, written and spoken.

Nice to Have

· Experience at a remittance company, money transmitter, payments processor, or neobank.

· Exposure to BSA/AML, KYC/CIP, OFAC screening, transaction monitoring, or PCI-DSS requirements.

· Experience with multi-tenant data isolation in Laravel (global scopes, tenant-aware queries).

· Experience with Filament or another Laravel-based admin panel framework.

· Experience with Laravel Reverb or WebSockets for real-time updates.

What We Offer

· Fully remote, flexible hours within the required U.S. time-zone overlap.

· A ground-floor seat at a fast-moving, AI-native fintech. You'll help shape the actual architecture, not inherit someone else's.

· Direct access to leadership. Decisions move fast here.

· Employee Stock Options.

How to Apply

Apply directly through this listing with your resume and, if you have one, a GitHub or portfolio link. In a few sentences, tell us about the most complex payment or money-movement integration you've built and one thing that went wrong in production.

Sueldo: A partir de $40,000.00 al mes

Beneficios:

• Horarios flexibles

Lugar de trabajo: Empleo remoto