Senior Software Engineer - Payment Processing - Contract

finalsite; Glastonbury (CT); Hybrid; USD 150,000 - 210,000; Full time

Job summary

Finalsite is hiring a senior backend engineer to modernize the payment reconciliation engine and scale fraud detection for a high‑volume fintech platform. This remote role supports US operations, focusing on end‑to‑end transaction tracking and automated reconciliation.

You will work with dual processor integrations, build a unified payments layer, and apply AI-assisted tools to navigate a large codebase while maintaining PCI‑DSS compliance.

Qualifications

• 8+ years backend engineering with reconciliation/transaction-processing experience
• PCI-DSS experience in transaction processing and reconciliation
• Bachelor's degree in CS/Engineering or equivalent
• Comfort with large monolithic codebases without modern service boundaries
• Ability to trace data across disconnected systems
• Independent backend architecture decisions: service boundaries and data modeling
• Experience with two parallel payment integrations
• Proficiency with .NET/Java/Python and SQL Server environments

Responsibilities

• Design and build automated, end-to-end transaction lifecycle tracking
• Help build fraud detection and chargeback management features
• Work across two parallel engine versions and processor integrations
• Collaborate with storefront team to expose data and close reconciliation gaps
• Prioritize quality, stability, and scalability as volumes grow
• Contribute to a unified payments layer across platforms
• Leverage AI-assisted tools to navigate a large multi-repo codebase

Skills

Backend engineering

PCI compliance

Data tracing

System design

SQL Server

Azure

Observability

AI tooling

Education

Bachelor's degree in CS/Engineering

Tools

Claude Code

Codex

Azure

Datadog

New Relic

Job description

WHO WE ARE

Finalsite is the most valued partner for K-12 schools to build trust, strengthen community, and grow enrollment. Ranked among the best EdTech Companies in America, Finalsite supports more than 7,000 schools and districts worldwide with an integrated platform for websites, communications, mobile apps, enrollment, and marketing services.

Headquartered in Glastonbury, Connecticut, Finalsite is a global company with employees working remotely across nearly every U.S. state, as well as throughout Europe, South America, and Asia.

We believe people do their best work when they feel supported, connected, and empowered to grow. That’s why we invest in our employees through competitive benefits, professional development opportunities, and a collaborative culture built on partnership and purpose. Whether you're looking to expand your skills, take on new challenges, or make a meaningful impact in education, Finalsite offers the opportunity to grow your career while helping schools thrive.

At Finalsite, every interaction matters - with our clients, with each other, and with the schools and families we serve. Join us and help shape stronger school communities around the world

SUMMARY

Finalsite's payment processing engine is the reconciliation and transaction-processing layer behind its payments business, and it carries some of the most consequential technical debt in the portfolio: no end-to-end transaction tracking, largely manual reconciliation, and two parallel versions of the engine running against separate processor integrations. Reaching baseline automated reconciliation is a substantial, multi-quarter effort already underway.

This is foundational, high-visibility work: closing a real reconciliation gap and helping build the engine into a modern platform, with real reconciliation, fraud detection, and chargeback management, that can scale with a growing payments business.

LOCATION

100% Remote - Anywhere in LatAm

RESPONSIBILITIES

• Design and build toward automated, end-to-end transaction lifecycle tracking, replacing today's manual reconciliation process
• Help build out fraud detection, chargeback management, and other automated payment functions the platform doesn't have today
• Work across the engine's two parallel versions and processor integrations to resolve mismatches and reconciliation gaps
• Partner with the storefront team to expose data that closes reconciliation gaps
• Focus on quality, core-flow stability, and scalability as transaction volume grows
• Help plan, and contribute to, a shared payments-unification layer across the payment processing engine, storefront, and events platform
• Use AI-assisted development tools (Claude Code, Codex, or comparable) to navigate a large, undocumented, multi-repository codebase

QUALIFICATIONS AND SKILLS

• 8+ years of overall engineering experience, including strong backend engineering experience, ideally including financial reconciliation, ledger, fraud, or transaction-processing systems
• Hands-on PCI compliance experience: familiarity with PCI-DSS requirements as they apply to transaction processing and reconciliation
• Bachelor's degree in Computer Science, Engineering, or a related field, or equivalent practical experience
• Comfort working in a large, non-microservices codebase spanning many repositories without modern service boundaries
• Demonstrated ability to trace and reason about data across disconnected systems
• Comfort making backend architecture decisions independently: service boundaries, data modeling, and system-design trade-offs
• Experience with third-party payment processor integrations, including running two integration versions in parallel
• Strong backend engineering fundamentals with a .NET / SQL Server-based stack, or a demonstrated ability to ramp quickly in one
• Working knowledge of relational database design and operations (SQL Server): schema design, query-performance tuning, and locking behavior at production scale
• Familiarity with running and debugging a production service in a cloud environment (Azure preferred)
• Demonstrated expertise in at least one programming language, ideally .NET, Java, or Python
• Experience with at least one observability platform (Datadog, New Relic, Honeycomb, or comparable)
• Deep experience with automated testing frameworks
• Proficiency with Claude Code, Codex, or comparable AI-assisted development tools

PREFERRED

• Experience with .NET or Java specifically
• Deep experience with Azure
• Experience building reconciliation, ledger, fraud-detection, chargeback, or other payment-operations systems specifically
• Prior work consolidating or migrating between two parallel versions of the same system
• Background in payments or fintech, particularly high-volume environments

RESIDENCY REQUIREMENT

Finalsite offers 100% fully remote employment opportunities, however, these opportunities are limited to permanent residents of the United States. Current residency, as well as continued residency, within the United States is required to obtain (and retain) employment with Finalsite.

DISCLOSURES

Finalsite is proud to be an equal opportunity workplace and is an affirmative action employer. We are committed to equal employment opportunity regardless of race, color, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender identity or Veteran status. We also consider qualified applicants regardless of criminal histories, consistent with legal requirements. EEO is the Law. If you have a disability or special need that requires accommodation, please contact Finalsite's People Operations Team. Finalsite is committed to the full inclusion of all qualified individuals. As part of this commitment, Finalsite will ensure that persons with disabilities or special needs are provided a reasonable accommodation. Ensure your Finalsite job offer is legitimate and don't fall victim to fraud. Ask your recruiter for a phone call or other type of verbal communication and ensure all email correspondence is from a finalsite.com email address. For added security, where possible, apply through our company website at finalsite.com/jobs.