Sr Full Stack Software Engineer - Digital Banking

American Express•Sunrise, FL

About The Position

American Express is hiring a Senior Full-Stack Software Engineer for its Digital Banking technology team and Control Tower platform. Control Tower provides mission-critical tools that help payment platforms operate safely and efficiently, supporting the development and operation of American Express financial products. The engineer will design and deliver capabilities across backend services, APIs, developer tooling, and operational user interfaces for a shared platform serving multiple products and tenants with distinct data, configuration, access, and operational requirements. This hands-on role leads the technical design and delivery of complex initiatives, contributes to platform direction, mentors engineers, and improves team standards and tooling. The engineer partners with product, architecture, operations, security, business, and engineering stakeholders to deliver secure, scalable, resilient, and high-quality platform services throughout the software development lifecycle. Employment eligibility to work with American Express in the United States is required; the company will not pursue visa sponsorship.

Requirements

Track record of designing and delivering complex production systems as a senior engineer.
Strong experience with Java or Kotlin and the JVM ecosystem.
Experience with asynchronous, reactive, or event-driven programming.
Practical knowledge of domain-driven design, including bounded contexts, aggregates, domain services, domain events, and integration between domains.
Strong API design skills, including HTTP semantics, schema design, compatibility, idempotency, pagination, error models, and contract testing.
Sound understanding of distributed-systems concepts, including consistency, availability, partitioning, concurrency, ordering, retries, and failure recovery.
Experience building fault-tolerant and horizontally scalable services.
Experience with data modeling, transactions, caching, schema evolution, and safe data migrations.
Ability to benchmark systems, diagnose bottlenecks, and make evidence-based performance improvements.
Experience designing or operating systems serving multiple tenants, products, or business units.
Understanding of tenant-isolation models and trade-offs between shared, partitioned, and dedicated infrastructure.
Experience enforcing tenant context across APIs, data access, background processing, events, caches, logs, and metrics.
Knowledge of identity, authentication, authorization, least privilege, and auditable access in multi-tenant systems.
Experience designing tenant-aware configuration, feature enablement, quotas, and lifecycle management without creating tenant-specific forks.
Ability to balance shared platform capabilities with individual product needs.
Experience identifying and preventing cross-tenant data exposure, resource contention, and configuration leakage.
Understanding of how tenant boundaries affect deployment, migration, monitoring, support, and incident response.
Strong JavaScript or TypeScript, HTML, and CSS skills.
Experience building production applications with React or a comparable component-based framework.
Experience with client-side architecture, state management, data fetching, error handling, and frontend testing.
Knowledge of semantic HTML, accessibility, responsive and adaptive design, and browser performance.
Ability to turn complex operational data into clear and usable interfaces, including interfaces for real-time data, degraded states, partial results, and operational errors.
Hands-on experience with large language model-assisted development workflows and coding agents such as Codex, GitHub Copilot, Claude Code, or comparable tools.
Ability to give agents clear context, constraints, acceptance criteria, and verification steps for complex engineering work.
Experience using agents for implementation, testing, debugging, refactoring, documentation, code analysis, and repetitive development tasks.
Judgment to identify work suited to agent assistance and work requiring direct investigation or human decision-making.
Disciplined review of generated code for correctness, security, performance, maintainability, and alignment with system architecture.
Understanding of common large language model failure modes, including incomplete context, incorrect assumptions, insecure suggestions, and plausible but invalid output.
Experience protecting source code, customer data, credentials, and other sensitive information when using approved artificial intelligence development tools.
Ability to create repeatable agent workflows and share effective practices with other engineers.
Accountability for code and technical decisions produced with agent assistance.
Ability to lead technical design for complex initiatives while remaining directly involved in implementation.
Strong written and verbal communication skills.
Ability to make trade-offs visible and help a team reach decisions.
Experience mentoring engineers and improving the quality of designs, code, and operational practices.
Judgment to choose established approaches when appropriate and introduce new technology only when it offers a clear benefit.
Ability to work through ambiguity while balancing delivery, safety, and collaboration.
Experience documenting technical decisions so engineers outside the original discussion can understand the context and constraints.
Ability to identify risks early, challenge assumptions, and adjust an approach when evidence shows it is not working.
Eligibility to work with American Express in the United States; visa sponsorship will not be pursued.

Responsibilities

Lead the design and implementation of full-stack platform capabilities, including domain models, backend services, APIs, and operational user interfaces.
Apply domain-driven design to identify bounded contexts, define ownership, and separate business rules from infrastructure concerns.
Design APIs with clear contracts, consistent resource models, predictable error handling, idempotency, versioning, and backward compatibility.
Design multi-tenant capabilities with explicit boundaries for data, identity, configuration, workloads, and resource consumption; address tenant isolation, authorization, quotas, noisy-neighbor risks, observability, onboarding, and migration.
Build distributed and event-driven systems that account for concurrency, ordering, consistency, retries, backpressure, partial failure, and delivery semantics.
Create processing and visualization components for real-time operational analysis.
Build accessible, responsive, and performant interfaces for operators and internal platform users.
Own services in production, including instrumentation, service-level objectives, capacity planning, incident response, and remediation.
Define testing strategies across unit, integration, API contract, end-to-end, performance, and resilience testing.
Improve build, test, deployment, and release tooling through the continuous integration and delivery pipeline.
Use and improve large language model-assisted development workflows while maintaining engineering, security, and review standards.
Evaluate technology choices based on reliability, security, maintainability, developer productivity, and lifecycle cost.
Write technical proposals and explain architectural decisions, constraints, and trade-offs.
Mentor engineers through design reviews, code reviews, pairing, and technical guidance.
Partner with product, operations, security, and engineering stakeholders to turn business requirements into technical outcomes.
Take ownership of complex work and drive it to completion when requirements are incomplete or evolving.