Senior Full-Stack AWS Engineer / Technical Lead — Fintech Lending Platform

Contract | 2–3 Month MVP Build | Remote
We are looking for a highly experienced Senior Full-Stack AWS Engineer / Technical Lead to rebuild an existing lending-platform proof of concept into a secure, scalable MVP running fully on AWS.
The current application is a functioning POC with the core workflows and business logic already defined. The goal is to rebuild it into a production-oriented architecture that can support future lender customers, integrations, stronger security controls, and continued product development.
The platform manages the loan lifecycle from customer intake and application management through age verification, amortization, servicing, payoff, delinquency treatment, collections, reporting, audit, and role-based access.
Current Product Scope
The existing LMS includes:
Customer and borrower profile management
Loan application management and lifecycle tracking
Inverite Age Verification integration
TValue-powered amortization and payment schedules
Versioned schedule revisions and reamortization
Loan servicing and installment management
Recording payments received externally
Partial and extra payments
Failed payments and reversals
Verified loan balances and Total Amount Owing
Fees and charges
Payoff quotes and payoff completion
Paid-Off and Closed account lifecycle
Delinquency and Days Past Due tracking
Collections queue and case management
Promises to pay, hardship, disputes, restrictions, arrangements and escalation
Role-based access for Admin, Staff and Reviewer users
Audit and activity history
Portfolio and operational reporting
Multi-tenant company isolation
The current servicing model includes verified balances, fees, Total Amount Owing, payoff, and closure controls.
What You’ll Do
You will take ownership of rebuilding the current POC into an AWS-based MVP.
Responsibilities include:
Review and reverse-engineer the existing Base44 application
Define the target AWS architecture
Rebuild the frontend and backend using a maintainable production stack
Design the multi-tenant data model
Implement secure authentication and authorization
Build APIs for frontend and external integrations
Rebuild customer, application, amortization, servicing, payoff, collections and reporting workflows
Integrate TValue APIs
Integrate Inverite Age Verify and webhook workflows
Implement webhook security, idempotency and retry handling
Implement financial event history and auditability
Build reporting and CSV export
Build development, staging and production environments
Implement CI/CD
Implement logging, monitoring and operational diagnostics
Build automated unit, integration and end-to-end tests
Document architecture, APIs, deployments and operational procedures
Support migration from the POC architecture into the MVP
Expected AWS Experience
We are open to strong architecture recommendations, but likely AWS services may include:
ECS/Fargate or Lambda
RDS PostgreSQL / Aurora PostgreSQL
S3
CloudFront
API Gateway or ALB
Cognito or equivalent authentication
Secrets Manager
KMS
CloudWatch
WAF
Route 53
IAM
Terraform, AWS CDK or CloudFormation
GitHub Actions, CodePipeline or equivalent CI/CD
We want someone who can recommend the simplest secure architecture that can scale, without over-engineering the MVP.
Required Experience
Senior-level full-stack development
AWS architecture and deployment
React or comparable modern frontend framework
Node.js / TypeScript backend development or comparable stack
PostgreSQL and relational data modeling
REST APIs
Multi-tenant SaaS architecture
Authentication and authorization
Role/capability-based access control
Third-party API integrations
Webhooks
Idempotency and retry handling
Transactional / financial system design
Automated testing
CI/CD
Infrastructure as Code
Observability and logging
Secure handling of secrets and sensitive customer data
You should be comfortable working on systems where financial records must be traceable and duplicate or unauthorized transactions are unacceptable.
Strongly Preferred
Experience in any of the following is a major advantage:
Fintech
Lending
Loan Management Systems
Loan servicing
Consumer finance
Collections platforms
Payment or transactional systems
Amortization engines
Banking integrations
Identity / age verification
Canadian financial services
PIPEDA / privacy controls
SOC 2 or comparable security controls
Important Product Boundaries
The current LMS records servicing activity and externally received payments. It does not currently process electronic funds, debit accounts, or move money.
Collections is also a manual workflow. The system records collection activity but does not automatically call, email or text borrowers.
What Success Looks Like
By the end of the engagement, we expect:
A working AWS-hosted MVP
Production-quality source code in our repository
Secure multi-tenant architecture
Core POC functionality successfully rebuilt
TValue and Inverite integrations operational
Loan servicing and collections functioning end-to-end
Reporting operational
Development, staging and production environments
CI/CD
Automated testing
Logging and monitoring
Technical and deployment documentation
A maintainable codebase another engineering team can continue developing
Engagement
Type: Contract / Project
Duration: Approximately 2–3 months
Commitment: Preferably full-time or substantial weekly availability
Location: Remote
Start: As soon as practical
There may be an opportunity for continued development after the MVP launch.
How to Apply
Please send:
A brief summary of relevant experience
Examples of fintech, lending, SaaS or financial systems you have built
Your AWS experience
Your preferred frontend/backend technology stack
Examples of API and webhook integrations you have implemented
Your availability over the next 2–3 months
Your hourly or project rate
GitHub, portfolio or relevant work samples
Please also answer:
How would you approach rebuilding a functioning low-code POC into a maintainable AWS application?
What AWS architecture would you recommend for this MVP, and why?
How would you design secure multi-tenant data isolation?
How would you prevent duplicate financial mutations and stale concurrent updates?
How would you structure servicing and audit event history?
What would you prioritize in the first two weeks of a 2–3 month rebuild?
We are looking for someone who combines hands-on engineering, AWS architecture experience, and strong technical judgment and can move quickly without compromising financial-data integrity.

Work arrangement
Yes