MERN Full-Stack Technical Lead Needed

Senior Full-Stack Integrator / Technical Lead

JOB TITLE: Senior Full-Stack Integrator / Technical Lead

LOCATION: Remote

EMPLOYMENT TYPE: Independent Contractor (3-month contract, with extension to 12 months)

START DATE: ASAP (April 2026)



ABOUT THE PROJECT

We have built three high-fidelity, custom-built modules:

Module A: React/TypeScript Frontend (15 screens, 40+ components, complete UI)

Module B: Python-based Matching Engine (AI/ML - Levenshtein, credit scoring, fraud detection)

Module C: Node.js API Gateway (database schemas, endpoints, security framework)

These modules are currently SILOED - they exist independently and need to be integrated into a unified, secure, and scalable financial platform.



YOUR MISSION: Serve as the "Lead Integrator" mapping these independent assets into a working system.



KEY RESPONSIBILITIES



1. SYSTEM ORCHESTRATION (30%)

Connect the AI/ML matching output to the UI dashboard via secure RESTful APIs

Ensure real-time data flow between all three modules

Implement proper error handling and retry logic

Set up message queues for async processing

Create unified logging across all services



2. API HANDSHAKING (25%)

Finalize the "pipes" between internal gateway and external Telco APIs

Implement bank webhook handlers (Finacle/Oracle - read-only)

Set up HMAC signature verification for payment callbacks

Configure Africa's Talking SMS gateway integration

Create fallback mechanisms for API failures



3. SECURITY HARDENING (20%)

Implement OAuth 2.0 / JWT authentication across all services

Apply AES-256 encryption for all PII fields at rest

Ensure TLS 1.3 for all data in transit

Set up role-based access control (6 user roles)

Configure audit logging for all system actions

Prepare for security audit and penetration testing



4. PERFORMANCE TUNING (15%)

Optimize communication between the "Brain" (Python) and the "Face" (React)

Ensure real-time data updates for bank officers (<500ms response)

Implement caching strategy (Redis)

Load test the system (target: 10,000 records/min)

Optimize database queries and indexes



5. TECHNICAL DOCUMENTATION (10%)

Maintain the "Master Blueprint" - architecture diagram, data flow, API specs

Document all integration points

Create deployment runbooks

Write setup guides for future developers

Ensure system is audit-ready for institutional partners



TECHNICAL REQUIREMENTS

MANDATORY SKILLS (The "Generalist" Mastery):

Expert-level React (TypeScript) - 4+ years

Expert-level Node.js (NestJS/Express) - 4+ years

Expert-level Python (FastAPI) - 3+ years

PostgreSQL or MongoDB - Advanced proficiency

REST API design and implementation

Docker and Kubernetes (basic to intermediate)

Git and CI/CD pipelines

Linux server administration

Strong English communication



NON-NEGOTIABLE REQUIREMENT:

Fintech Experience: Previous work with payment gateways, reconciliation tools, or banking middleware. You must have built or integrated systems that handle financial transactions.

│ This is critical - banking partners will audit this experience.

│ Examples of acceptable experience:

│ ├── Worked on mobile money integrations (MTN MoMo, Orange Money, M-Pesa)

│ ├── Built bank API connectors (Finacle, Oracle, Temenos, or similar)

│ ├── Developed reconciliation engines for payments

│ ├── Implemented fraud detection systems

│ └── Deployed systems in regulated environments (finance, healthcare, government)



NICE TO HAVE:

├── Experience with Africa's Talking SMS gateway

├── Knowledge of Levenshtein distance or fuzzy matching algorithms

├── Experience with ML model deployment (TensorFlow, PyTorch)

├── Previous work with microservices architecture

├── Experience with Elasticsearch, Kibana (ELK stack)

├── Familiarity with banking regulations (data protection, PCI-DSS)

└── Existing relationships with telco or bank technical teams



WHAT WE ALREADY HAVE (The Assets You'll Integrate)

We are NOT starting from scratch. The following assets are already built and ready:



MODULE A: FRONTEND (React/TypeScript) - 8,000+ lines

· 15 complete screens (Login, Dashboards, Identity Center, Heat Maps, etc.)

· 40+ reusable components (Storybook)

· 20+ charts (Recharts, D3.js)

· Complete TypeScript types and interfaces

· Tailwind CSS with dark mode

· Role-based rendering (6 roles)

· WebSocket client for real-time updates

· CSV upload wizard with validation



MODULE B: MATCHING ENGINE (Python/AI) - 3,000+ lines

· Levenshtein distance algorithm (identity matching)

· Credit scoring model (XGBoost - trained)

· Fraud detection engine (SIM swap, geo, multiple loans)

· Freeze optimizer (success prediction)

· Travel detector (roaming detection)

· Mock data generator

· FastAPI endpoints ready



MODULE C: API GATEWAY (Node.js) - 5,000+ lines

· Database schema (15 tables with encryption)

· 50+ REST endpoints defined

· OAuth 2.0 framework

· RBAC middleware (6 roles)

· Audit logging service

· WebSocket server

· Docker configuration

· Bank/telco connector placeholders (ready for your keys)



YOUR JOB: Connect these pieces into ONE working system.


HOW TO APPLY


1. Resume/CV

2. GitHub/GitLab profile with relevant code

3. Brief description of a fintech or integration project you've led

4. Your availability (hours per week, start date)

5. Your expected rate (monthly or total)

6. Confirmation that you have fintech experience



USE SUBJECT LINE: "Lead Integrator Application - [Your Name]"



NOTE TO APPLICANTS



This role is for a "system integrator" - you will NOT be building from scratch.

You will be taking three high-quality, already-built modules and making them work together.



If you enjoy:

· Connecting systems

· Solving integration puzzles

· Making complex things work simply

· Working with pre-existing code

· Building for regulated environments



...this is the perfect role for you.

If you prefer:

· Building from scratch

· Working alone on one technology

· Avoiding documentation

· Quick prototypes



...this role may not be a good fit. Show More