Senior Software Engineer – Payments - Payments, Credit Card & Alternative Payments

RESPONSIBILITIES

Credit Card Payment Processing
Implement and maintain scalable, fault-tolerant services handling real-time authorization, batch clearing, and settlement workflows.
Build and maintain integrations with acquiring banks, card networks (Visa, Mastercard, Amex, Discover), payment gateways, fraud providers, and tokenization services.
Implement resilient routing logic, retry strategies, and failover mechanisms across card network connections.
Ensure transaction idempotency and correct state management across the full card payment lifecycle.
Support 3D Secure (3DS2) and Strong Customer Authentication (SCA) flows.
Implement and maintain card vaulting and tokenization solutions in line with PCI DSS requirements.
Alternative Payment Methods (APMs)
Build and maintain integrations with a broad range of APMs, including digital wallets (PayPal, Apple Pay, Google Pay), bank transfers (ACH, SEPA, instant bank pay), buy now pay later (BNPL) providers, prepaid and voucher methods, and regional local payment methods across key markets.
Design flexible, extensible integration patterns that allow rapid onboarding of new payment methods and providers.
Handle the unique lifecycle requirements of each payment method — including asynchronous notifications, delayed confirmations, refund flows, and currency/settlement nuances.
Collaborate with Product to evaluate and prioritize new APM integrations based on market coverage and player demand.
Reconciliation & Financial Integrity
Build and maintain automated reconciliation pipelines that match authorization, clearing, and settlement records across both card and APM payment rails.
Reconcile internal ledgers against acquirer, network, and PSP reports; detect and surface mismatches, duplicates, and missing transactions.
Develop safeguards to prevent revenue leakage and ensure ledger consistency at scale.
Ensure all financial systems are audit-ready and compliant with internal financial controls.
Reporting, Monitoring & Alerting
Build and maintain payment reporting systems covering authorization rates, settlement reconciliation, interchange and fee breakdowns, APM conversion rates, and chargeback/dispute metrics.
Implement threshold-based alerting for authorization rate drops, decline pattern anomalies, settlement mismatches, volume spikes, and chargeback ratio changes across all payment methods.
Contribute to internal financial dashboards supporting cost optimization, risk monitoring, and financial performance visibility.
Participate in on-call rotations and incident response for payment-critical systems.
Compliance & Security
Build systems compliant with PCI DSS, card network operating regulations, data encryption and tokenization standards, and regional mandates.
Contribute to secure handling of sensitive payment data across card and APM flows.
Support audit processes and financial compliance reviews as required.
Fraud & Dispute Management
Integrate with fraud detection and risk scoring systems across card and APM payment flows.
Implement chargeback and dispute workflow components, including evidence submission and representment support.
Build safeguards and monitoring for fraud pattern detection across payment methods.
Engineering Excellence
Write clean, well-tested, well-documented code with a strong focus on reliability, observability, and correctness.
Participate actively in code reviews, technical design discussions, and architecture decisions.
Contribute to best practices for distributed systems design, observability, incident response, and financial data integrity.
Mentor junior engineers and contribute to a high-trust, high-accountability engineering culture.

QUALIFICATIONS & SKILLS

5+ years of software engineering experience, with a strong focus on PHP and Go (Golang) tech stacks
at least 2+ years working on payment processing systems in production
Hands-on experience with card payment flows: authorization, clearing, settlement, reconciliation, and chargebacks.
Experience integrating with or building against one or more APM providers (wallets, bank transfers, BNPL, local payment methods).
Solid understanding of the four-party (Visa/Mastercard) and three-party (Amex/Discover) models, including interchange, BIN logic, MCC codes, AVS, CVV, and 3DS/SCA.
Strong understanding of distributed systems: idempotency, eventual consistency, fault tolerance, and high availability.
Proficiency in designing and consuming RESTful and/or event-driven APIs in a payments context.
Familiarity with PCI DSS and payment data security fundamentals.
Strong debugging and incident response skills in complex, high-volume financial systems.
 
NICE TO HAVE
 
Experience at a PSP, acquirer, issuer, payment gateway, or fintech platform.
Familiarity with global payments and cross-border processing, including FX, local settlement, and regulatory considerations.
Experience at high transaction volumes (10M+ monthly transactions).
Exposure to authorization rate optimization and intelligent payment routing.
Familiarity with the gaming, digital goods, or e-commerce payments landscape.
Experience with audit processes and financial compliance reviews.

WHAT SUCCESS LOOKS LIKE

In your first 6 months, you will have:
Delivered meaningful improvements to at least one area of the card or APM payment stack — whether a new integration, a reconciliation improvement, or a reliability/observability uplift.
Demonstrated deep ownership of a payment domain area, proactively identifying and resolving gaps in reliability, correctness, or coverage.
Built strong working relationships with the Tech Lead, PM, and cross-functional stakeholders across Finance and Risk.
Contributed to engineering practices that raise the quality bar for the broader payments team.