Senior Backend Engineer – Payments, Go, TypeScript, Node.js

This is a fully remote position, open to applicants in Ukraine, +5 more countries.

📋 Description

• Become a part of a product team focused on developing payment infrastructure for merchants and partner platforms.

• Take ownership of comprehensive payment flows in TypeScript/NestJS services, covering authorization, capture, void, refund, dispute management, and payout initiation and confirmation.

• Create and sustain acquirer and processor integrations utilizing clean internal abstractions.

• Design embedded and hosted checkout experiences, incorporating hosted fields, iframes, and tokenization to reduce PCI scope.

• Execute fee calculation and rate logic, which includes tiers, interchange-plus, flat structures, rounding rules, special rates, and edge cases.

• Develop reconciliation and settlement layers that align processor reports and settlement files with internal records.

• Architect event handling using idempotency keys, out-of-order and duplicate webhooks, retries with backoff, and state machines.

• Integrate fraud detection, bank-account verification, and KYC providers, optimizing decision-making based on real outcomes.

• Manage ACH mechanics, including submission windows, returns, return codes, NOCs, and retry protocols.

• Ensure domain accuracy, maintain thorough audit trails, and provide reconciliation evidence.

• Serve as the team's payments authority, advising product on rail capabilities and reviewing payment-related code.

• Collaborate daily with a US-based team, ensuring 4–6 hours of overlap with US Central Time.

⛳️ Requirements

• Over 6 years of professional software engineering experience.

• Minimum of 3 years of direct experience with payment systems or payment processing.

• Solid backend engineering experience with Go, TypeScript, and Node.js.

• Proven track record of owning production payment flows rather than solely executing basic payment API integrations.

• Experience with payment processors, gateways, or acquirers such as Stripe, Adyen, Braintree, Checkout.com, Worldpay, Fiserv, or other similar providers.

• Deep understanding of the card payment lifecycle, encompassing authorization, capture, settlement, refunds, chargebacks, and disputes.

• Familiarity with bank payment rails, preferably with ACH/NACHA concepts, including returns and transaction timing.

• Experience in payment reconciliation and settlement.

• Strong grasp of webhooks, retries, idempotency, asynchronous processing, and distributed-system failure scenarios.

• Experience in designing relational data models for transaction-intensive systems.

• Knowledge of PCI DSS and payment-security practices such as tokenization and the isolation of sensitive payment data.

• Strong focus on accuracy and edge cases, particularly in financial systems.

• Proficiency with modern AI-assisted development tools.

• Excellent English communication skills and confidence in collaborating directly with a US-based team.

• Willingness to maintain 4–6 hours of daily overlap with US Central Time.

• Bonus: Experience with platform, marketplace, or facilitator models, including split payments, sub-merchant onboarding, and multi-party flows.

• Bonus: Familiarity with payouts and disbursement rails, such as bank-account collection, verification, and payout status management.

• Bonus: Experience with fraud and risk management tools, as well as bank-account validation services.

• Bonus: Background in e-commerce plugin or SDK development for platforms like WooCommerce, Shopify, or Magento.

• Bonus: Understanding of multi-currency, cross-border, or alternative payment methods.

• Bonus: Experience with event sourcing related to financial states and double-entry ledger design.

🏝️ Benefits

• Fully remote work opportunities available globally, or hybrid work from office hubs.

• Flexible work schedule.

• Consistent workload and reliable income.

• Performance evaluations and career development paths.

• Mentorship program.

• Personal development plans.

• Access to individual learning resources through the corporate library.

• Support for public speaking initiatives.

• Company-wide technology and cultural events.

• A supportive and flexible work environment that values collaboration, open communication, and mutual respect.

• Engaging CSR initiatives.