Senior Backend Engineer - ChainIT Pay

• ChainIT Pay - PayFac/ISO payment processing, merchant onboarding, disbursements, and regulated payment flows
• Pactvera - court-enforceable biometric smart agreements (1,000+ business rules)
• Sportafi - NIL payment automation and Title IX reporting for college athletics
• Age App - privacy-first age verification (no PII stored)
• ChainITX - physical-to-digital asset tokenization (ERC-721)
• Touch Audit - HIPAA-aligned zero-knowledge audit trails
• ChainIT SDK - launched at Consensus 2025

Customers include U.S. banks, mortgage lenders, and government agencies.

Our philosophy: Truth over Trust - nothing is assumed, everything is verified.

The Role

You will own and evolve the payments-focused backend services that power ChainIT Pay - our PayFac/ISO payment processing platform. Your work sits at the intersection of regulated payment flows, merchant lifecycle management, and the shared ChainIT platform layer.

This is not a greenfield role. You will inherit a production codebase that:

• Runs 25+ Nx-managed microservices using CQRS + hexagonal architecture
• Persists audit-grade records to Amazon QLDB (immutable ledger) alongside per-service Postgres
• Integrates with ~40 external systems including payment processors and rails (Paysafe, Plaid, ACH networks), AWS services (Cognito, KMS, S3), identity providers (Incode, IDScan, Regula), and more
• Communicates over dual transport (HTTP/REST + RabbitMQ quorum queues)

Unlike our product-assigned Full Stack Engineers, this role is payments-platform-first: you serve ChainIT Pay and its downstream consumers, ensuring payment processing, merchant onboarding, disbursements, and compliance flows are reliable, auditable, and scalable.

What You Will Own

• Architecture and implementation decisions across ChainIT Pay backend services (candidates include: payment processing, merchant onboarding, disbursement orchestration, settlement reconciliation, transaction monitoring, subscriptions, reports, notifications - scope assigned at onboarding)
• CQRS command/query handlers, domain aggregates, and RabbitMQ event flows for payment lifecycle events
• TypeORM schema design, migrations, and indexing for per-service Postgres databases
• QLDB ledger integration for immutable audit records (Validated Data Tokens)
• API versioning and OpenAPI / AsyncAPI contracts consumed by our new AI-Agent Contracts Hub - the cross-org source of truth for AI coding agents working across every BIT codebase
• Integration with payment processors and rails (Paysafe, Plaid, ACH, card-present, disbursement networks) - maintaining, extending, and hardening these integrations
• Test strategy rollout: schema-lockfile diff runners, service-level integration tests against real Postgres, contract tests
• Code review for Full Stack Engineers on product teams whose UIs consume your services
• Production on-call rotation (EKS / Helm / PM2 cluster), * Amazon QLDB or other immutable ledger systems (Immudb, Azure Confidential Ledger)
• Web3 integrations: ethers.js, Alchemy, AWS KMS signers, ERC-721 / ERC-20 interaction
• Experience introducing a test framework into a production codebase with little or no existing coverage
• Biometric / identity verification domain (IDV vendors, liveness detection, eKYC)
• OpenAPI / AsyncAPI tooling and contract-first API design
• PayFac/ISO operations - merchant underwriting, sponsor bank relationships, PCI-DSS compliance, chargeback management
• AML/KYC/KYB compliance engineering - building or integrating transaction monitoring, sanctions screening, or suspicious activity reporting systems

Stack You Will Work With

• Language / Runtime: TypeScript 5.1, Node.js 20.15, Yarn 1.x
• Framework: NestJS 10 (CQRS, Microservices / RMQ, TypeORM, Mongoose, GraphQL, Bull, Swagger)
• Monorepo: Nx 16 - 25+ apps + shared libraries
• Persistence: TypeORM 0.3 + Postgres (per-service DB), Mongoose 6, Amazon QLDB
• Messaging: RabbitMQ (quorum queues), Redis, Bull
• Cloud / Infra: AWS SDK v3 (S3, Cognito, Rekognition, KMS, SES v2, SNS, Route 53), AWS CDK, EKS + Helm, PM2 cluster in containers
• Observability: pino + Sentry
• Testing: Jest 29 (currently under-utilized - you will help change that)
• Auth: JWT + Passport + custom auth middleware
• Web3: ethers 6, Alchemy SDK, AWS KMS Web3 signers
• Payments: Paysafe, Plaid, ACH processing, card-present integrations

Why This Role Is Worth Your Time

• Real payments, real regulation. You’ll work with live payment rails, ACH flows, disbursement orchestration, and merchant onboarding - not sandboxed demos.
• You install the safety net. A production platform with zero test coverage is a rare opportunity to define what “done” means going forward.
• Platform leverage. ChainIT Pay rides on the shared platform. One well-designed change compounds across the entire product portfolio.
• AI-native engineering. We are building an agent-consumable contracts hub so AI coding agents across the org always ground in one current, versioned source of truth. You will help shape it.
• Patent-backed technology. 14+ U.S. patents on identity, tokenization, and verification primitives - you will be implementing the real thing, not a wrapper.

Do you have experience in SQL databases?, * 5+ years of production backend engineering, with 3+ years in TypeScript or another strongly-typed OO language (Java, C#, Kotlin)

• 2+ years of NestJS, or deep experience in an equivalent DI-first framework (Spring Boot, ASP.NET Core, Ruby on Rails)
• Strong relational database fundamentals: schema design, migrations, indexing, query tuning. Postgres preferred.
• Production experience with at least one queue/streaming system (RabbitMQ, SQS, Kafka, NATS)
• Comfortable operating in AWS: S3, IAM, Secrets Manager, ECR, and Kubernetes (EKS)
• Demonstrable habit of writing testable code. You know what good test coverage looks like even if prior codebases lacked it.
• Experience working in a monorepo (Nx, Turborepo, Bazel, Lerna, or similar)
• Payment industry experience - familiarity with payment rails, processors (e.g. Paysafe, Stripe, Plaid), or regulated payment flows (ACH, card-present, disbursements). We already integrate with Plaid and Paysafe; prior exposure here shortens the learning curve.
• Prior work in a regulated industry (FinTech, HealthTech, GovTech, gaming), * Back-end development: 3 years (Required)
• Next.js: 2 years (Required)
• AWS: 3 years (Required)

Pulled from the full job description

• 401(k)
• 401(k) matching
• Paid time off, * Integration tests hit a real Postgres. We never mock the database - a past mock/prod divergence masked a broken migration.
• Zero raw PII exported from production. Ever.
• AWS roles used by agent-reachable services are read-only and may never have secretsmanager:GetSecretValue. Names yes, values no, forever.
• Breaking contract changes require a code-owner approved PR with the breaking-approved label. No auto-merge.
• Code-freeze boundaries on certain parts of the platform are enforced - new work happens in designated extension directories. Your tech lead will walk you through this during onboarding.
• Payment-related data handling must comply with PCI-DSS requirements. No cardholder data in logs, no PAN storage outside approved vaults.

Pay: $80,000.00 - $115,000.00 per year, * 401(k)

• 401(k) matching
• Paid time off

Application Question(s):

• Describe a payment or financial integration you built or maintained in production. What processor/rails were involved, and what was the hardest engineering problem you solved?
• Tell us about a time you inherited a production codebase with significant technical debt or missing test coverage. What was your approach, and what did you prioritize first?