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Job Description: ABOUT NYMBUS Nymbus (https://nymbus.com/) is not just a leader in fintech; we are a community of innovators passionate about reimagining banking. Our modern core platform and cloud based technology serve as the backbone for financial institutions eager to modernize and excel. Nymbus is building the next generation of fintech platforms and that requires a new kind of delivery leader. This role is the quality and release backbone of the squad — the person who ensures what gets built actually reaches production reliably, correctly, and on cadence. You will own delivery, validation, and operational readiness using AI-first methodology, working hand-in-hand with your Builder and Architect to ship outcomes end-to-end. WORK ENVIRONMENT: We are a remote first company, with occasional travel required for team collaboration or client engagement. POSITION SUMMARY: The AI Product Builder — Payments will help define and build the next generation of payment capabilities at Nymbus, including support for multiple payment rails, networks, message standards, settlement models, and integration patterns. At the heart of this role is a straightforward but demanding mandate: help us build sophisticated, extensible payment capabilities that financial institutions can depend on. You will own the transformation of complex payment-domain problems into working, production-ready software. You will design system behavior, author implementation-ready specifications, shape APIs and data models, prototype solutions, and participate directly in implementation using AI-assisted development workflows. You must understand how money moves—not only at the feature or requirements level, but at the system, message, transaction, settlement, and operational levels. You should be able to trace a payment from initiation through validation, routing, clearing, settlement, posting, reconciliation, and exception handling. You understand that the difficult parts of payments live in timeouts, duplicate messages, reversals, returns, cutoffs, partial failures, unavailable endpoints, liquidity constraints, and ambiguous transaction states. This is not a traditional product owner or requirements-writer role. You will not simply maintain a backlog and hand requirements to an engineering team. You are the primary product maker and payments-domain builder within the squad. Hands-on software development experience is strongly preferred. We will also consider an exceptionally technical payments expert who has demonstrated the ability to design buildable software systems, reason at the code and data-model level, and work directly with engineers through implementation. The ideal candidate may have previously operated as a principal engineer, payments architect, payment-platform builder, technical product leader, or deeply technical payments operator. Regardless of title, you have personally helped build or substantially shape sophisticated payment infrastructure. THE SQUAD TRIAD MODEL You will operate as one-third of a high-autonomy squad: Builder — This Role: Owns payment-product intent, detailed system behavior, specification, and implementation. You are the primary creator, translating payment-domain problems into working software and using AI tools to accelerate design, development, and iteration. Architect — Your Partner: Owns system architecture, technical integrity, and cross-squad consistency. You will collaborate daily on service boundaries, payment state models, API contracts, data architecture, integration patterns, security, scalability, and resilience. Shipper — Your Partner: Owns delivery discipline, quality assurance, release management, and operational readiness. You will collaborate on acceptance criteria, automated testing, rail certification, observability, deployment, production validation, and incident readiness. Together, the triad owns the complete outcome—from problem definition through production operation. ESSENTIAL JOB FUNCTIONS AND RESPONSIBILITIES Payments Vision and Domain OwnershipHelp define and execute the product vision for modern, extensible payment capabilities supporting multiple payment rails.Translate payment strategies, client needs, network rules, operational realities, and regulatory constraints into buildable platform capabilities.Design payment flows spanning initiation, validation, enrichment, authorization, routing, clearing, settlement, posting, notification, reconciliation, returns, reversals, disputes, and investigations.Define common payment concepts and patterns while preserving the scheme-specific behavior required by individual payment networks.Design canonical payment models, transaction state machines, message transformations, lifecycle events, and exception taxonomies.Make informed product and technical tradeoffs involving speed, cost, finality, liquidity, risk, customer experience, operational complexity, and network availability.Develop a cohesive vision for how payment capabilities should work together rather than treating each rail as an isolated integration.Build with extensibility in mind so new rails, networks, message versions, clients, and payment use cases can be added without redesigning the underlying capabilities. Payment Processing and OrchestrationDesign and build capabilities for payment initiation, routing, orchestration, message validation, enrichment, transformation, and delivery.Define behavior for synchronous and asynchronous payment flows, including long-running and indeterminate transaction states.Design controls for idempotency, duplicate detection, sequencing, retries, timeouts, reversals, compensating actions, and replay.Define how the platform manages acknowledgments, network responses, status changes, rejects, returns, cancellations, and exception repair.Build APIs and event-driven interactions that expose clear, predictable payment behavior to internal and external consumers.Ensure payment status and transaction history remain explainable and traceable across services, integrations, and payment rails.Design operational tooling that enables support and payment-operations teams to inspect, understand, repair, and resolve transactions safely. Payment Standards, Rails, and Connectivity Apply deep expertise across payment networks, standards, and integration patterns, including:ISO 8583, including message types, data elements, network-specific variants, authorization flows, reversals, advice messages, and clearing interactions.ISO 20022, including relevant pain, pacs, and camt message families; message mapping; scheme-specific extensions; version management; and end-to-end transaction identification.ACH, including origination, file- and API-based processing, settlement windows, returns, notices of change, reversals, same-day processing, and exception handling.Domestic and international wires, including applicable Fedwire and SWIFT concepts, cutoffs, acknowledgments, settlement, repair, and investigations.Real-Time Payments, including The Clearing House RTP network, immediate payment confirmation, request-for-payment capabilities, message sequencing, and irrevocability.FedNow, including instant payment processing, network messages, liquidity considerations, operating controls, and exception scenarios.Payment APIs, including secure initiation, status, account validation, callbacks, webhooks, event delivery, versioning, idempotency, and client-facing error handling.Card and payment-network flows, where applicable, including authorization, clearing, settlement, reversals, and network message processing. You will also help establish repeatable patterns for payment-rail connectivity, message transformation, certification, configuration, and client onboarding. Settlement and Liquidity ManagementDesign product behavior supporting settlement positions, funding requirements, prefunding, intraday balances, transaction limits, queues, cutoffs, and liquidity controls.Understand the relationship between payment processing, account balances, core posting, general ledger activity, settlement accounts, and reconciliation.Define how the platform should behave when funding is insufficient, limits are reached, settlement endpoints are unavailable, or liquidity conditions change.Partner with banking, treasury, finance, risk, and operations stakeholders to translate liquidity and settlement requirements into automated platform behavior.Provide transparency into current and projected payment positions, queued transactions, settlement obligations, and operational exposure. Product Design and SpecificationOwn end-to-end product design from problem definition through system behavior, implementation, and production validation.Author clear, testable, implementation-ready specifications using AI-assisted, spec-driven workflows.Create API contracts, event definitions, message maps, state-transition models, sequence diagrams, data models, validation rules, error models, and operational scenarios.Define requirements with enough technical and domain precision that they can be implemented and tested without losing critical payment behavior.Model both the happy path and the difficult paths, including duplicate messages, late responses, out-of-order events, inconsistent statuses, network outages, timeouts, retries, and manual interventions.Prototype and validate solutions before committing to full implementation.Push through ambiguity by investigating, proposing, prototyping, and building to learn rather than waiting for complete requirements. AI-First Building and ImplementationUse AI-assisted development tools, including Kiro and Claude, as primary components of the product-development workflow.Use AI to explore designs, challenge assumptions, identify edge cases, generate specifications, develop prototypes, write and review code, create tests, and accelerate iteration.Build reusable domain context, prompts, examples, test fixtures, and specifications that improve the quality of AI-generated outputs.Critically evaluate AI-generated designs and code for correctness, security, maintainability, performance, and payment-domain accuracy.Participate directly in implementation. Depending on your background, this may include writing production code, modifying services, creating prototypes, reviewing pull requests, inspecting logs and traces, or working alongside engineers at the code level.Treat AI as a force multiplier—not as a substitute for payments expertise, technical judgment, or accountability. Squad CollaborationPartner daily with the Architect on system boundaries, API design, data models, event models, resilience patterns, security, and platform architecture.Coordinate with the Shipper on acceptance criteria, test strategy, certification requirements, release readiness, observability, rollback approaches, and operational support.Participate directly in technical design discussions and make informed tradeoff decisions with the full triad.Collaborate with clients, payment operations, compliance, finance, treasury, engineering, and other domain experts without becoming dependent on committee-driven decision-making.Surface risks, blockers, assumptions, and cross-squad dependencies early.Maintain shared context through specifications, decision records, working software, test scenarios, message examples, and product demonstrations. Quality, Resilience, and Production OwnershipDesign payment capabilities for correctness, availability, auditability, security, scalability, and operational resilience.Define test scenarios that reflect real payment behavior rather than only validating basic functional requirements.Build or help build automated tests for payment state transitions, message transformations, network responses, failure conditions, and exception scenarios.Ensure sufficient logging, tracing, metrics, alerting, and transaction-level observability are designed into every capability.Participate in diagnosing production issues through transaction traces, payment messages, events, data records, and code.Remain accountable after release. You do not hand off a feature and walk away; you stay engaged until the capability works reliably in production. QUALIFICATIONS Payments ExperienceSeven or more years of experience building, designing, operating, or leading sophisticated payment systems within fintech, banking, financial services, payment networks, or payment technology.Demonstrated experience with payment switches, gateways, orchestration platforms, payment engines, processors, core-payment services, or similarly complex transaction-processing systems.Deep understanding of payment lifecycles, including initiation, authorization, clearing, settlement, posting, reconciliation, returns, reversals, rejects, and exception handling.Substantial experience with several of the following: ISO 8583, ISO 20022, ACH, wires, RTP, FedNow, payment APIs, card-network processing, settlement, and liquidity management.Ability to explain not only how a payment rail works, but how its rules and behavior should be represented in software.Experience shipping payment capabilities into production and supporting them through real operational conditions.Strong understanding of the correctness, control, security, auditability, and resilience expectations associated with regulated financial systems. Technical FluencyAbility to reason deeply about software architecture, service interactions, data models, APIs, event flows, transaction boundaries, and distributed-system failure modes.Ability to read code, API definitions, database schemas, logs, traces, and payment messages and use them to diagnose system behavior.Strong understanding of REST APIs, asynchronous messaging, event-driven systems, data persistence, versioning, authentication, authorization, and integration patterns.Working knowledge of distributed-system concepts such as idempotency, ordering, retries, eventual consistency, concurrency, duplicate processing, timeouts, and compensating transactions.Proven ability to create system specifications that are technically implementable and operationally complete.Hands-on production software-development experience is strongly preferred.Candidates without recent hands-on coding experience must demonstrate exceptional technical depth and a history of directly shaping software at the architecture, data-model, API, workflow, and implementation levels. AI-First MindsetActive, hands-on experience using AI-assisted development tools for product design, specification, prototyping, coding, testing, analysis, or technical documentation.Demonstrated ability to use AI to accelerate delivery while maintaining strong independent judgment.Willingness to experiment continuously with AI-augmented workflows and improve how the squad designs and builds software.Comfort working in a spec-first, AI-first development model in which specifications, code, tests, and implementation evolve together. PREFERRED EXPERIENCEDirect experience designing or building system