Senior AWS Full Stack Engineer (Banking Core Systems)

About Infinitive
Infinitive is a data and AI consultancy that enables its clients to modernize, monetize and operationalize their data to create lasting and substantial value. We possess deep industry and technology expertise to drive and sustain adoption of new capabilities. We match our people and personalities to our clients' culture while bringing the right mix of talent and skills to enable high return on investment.

Infinitive has been named “Best Small Firms to Work For” by Consulting Magazine 8 times, most recently in 2025. Infinitive has also been named a Washington Post “Top Workplace”, Washington Business Journal “Best Places to Work”, and Virginia Business “Best Places to Work.”

Role Overview

We are seeking a high-caliber Senior AWS Full Stack Engineer with deep domain expertise in Core Banking and Card Management Systems. This is a mission-critical role responsible for designing, building, and maintaining the engine of our clients financial services platform.

You will bridge the gap between complex financial logic and scalable cloud infrastructure, ensuring that our ledger, payment, and credit systems are resilient, secure, and lightning-fast.

Key Responsibilities

In this role, you will lead the development and integration across the following core functional domains:

• Customer & Account Management: Build robust systems for KYC, customer onboarding, and multi-currency account lifecycle management.

• Transaction Processing & Deposits: Engineer high-throughput engines for real-time deposit processing, interest calculations, and transaction posting.

• Lending & Credit Management: Develop automated workflows for loan origination, credit scoring integrations, and repayment scheduling.

• Payments & Money Movement: Architect secure rails for ACH, Wire, and real-time payments, ensuring 100% data integrity and reconciliation.

• Card Management (Debit & Credit): Manage the full card lifecycle, including issuance, authorization, clearing, and fraud detection hooks.

• Financial Ledger: Build and maintain a double-entry General Ledger system that serves as the "source of truth" for all financial accounting.

• Orchestration & Integration: Design a seamless middleware layer to connect internal product engines with external banking channels and third-party APIs.

Technical Qualifications

• Cloud Infrastructure: Expert-level experience with AWS (Lambda, DynamoDB, Aurora, SQS/SNS, Step Functions, and EKS).

• Full Stack Proficiency: * Backend: Java, Go, or Node.js (highly optimized for financial transactions).

  • Frontend: React or Angular for building sophisticated internal administrative and customer portals.

• Banking Domain: Proven experience with Core Banking Systems  (CBS) and ISO 20022 or ISO 8583 messaging standards.

• Data Consistency: Deep understanding of distributed systems, ACID properties, and eventual consistency in a banking context.

• Security: Experience with PCI-DSS compliance, OAuth2, and mutual TLS (mTLS).

Experience Requirements

• 7+ years in software engineering, with at least 4 years focused on AWS cloud-native architectures.

• 3+ years of direct experience in Fintech or Traditional Banking Core systems.

• Experience building or migrating "Product & Pricing Engines" that allow for dynamic financial product configuration.

Preferred Attributes

• You understand that in banking, "almost correct" is a failure—you prioritize precision and testing above all.

• You have experience with event-driven architecture to handle high-volume "Money Movement" asynchronously.

• You are comfortable navigating the Integration & Orchestration layer, connecting legacy systems with modern microservices.