Senior Full-Stack FinTech Engineer / Solution Architect – B2B & B2C Investment Platform

Project Overview We are looking for an experienced Senior Full-Stack Developer / FinTech Engineer / Solution Architect to design and develop a secure, scalable B2B + B2C investment and wealth management platform. The platform will support approximately 200 concurrent users initially, with an architecture designed to scale further. It will serve B2C customers, distributors/vendors, relationship managers, operations teams and platform administrators. The system will cover: Customer registration and onboarding KYC / PAN / identity verification Mutual Funds, SIP, SIF and other investment products Portfolio management Investment transactions Payment integration Financial planning and calculators Distributor/B2B management Customer, product and portfolio analytics Historical and trend analysis Customer, distributor and admin reporting External integrations with financial-data/KYC providers Secure cloud deployment, CI/CD, monitoring and disaster recovery Core Technical Scope Frontend The proposed frontend stack is: Next.js React TypeScript Tailwind CSS Shadcn UI TanStack Query Apache ECharts The application will contain separate dashboards and workflows for customers, distributors, relationship managers and administrators. Backend The proposed backend stack is: NestJS TypeScript REST APIs Background workers Redis RabbitMQ/BullMQ initially The backend must implement strong authentication, authorization, RBAC, tenant/distributor-level data isolation and audit logging. Database & Analytics The proposed architecture uses: PostgreSQL – transactional/OLTP database ClickHouse – analytical database and historical reporting Redis – caching Python + Apache Airflow – ETL/ELT dbt – optional analytical transformation layer DigitalOcean Spaces – raw/source data storage FinTech / Investment Features The system will include: Mutual Fund product discovery SIP setup and tracking SIF information and eligibility Portfolio holdings Investment transactions Current value and invested amount Profit/loss XIRR/annualized returns Asset/product allocation Historical investment information Purchase, SIP registration, additional investment, redemption and switch/cancellation where supported by providers. KYC & Onboarding The developer will work on integration with approved KYC/verification providers, potentially including: PAN verification CKYC/eKYC Identity verification Document verification KYC status management Rejection/resubmission workflows Analytics & Reporting The platform requires substantial reporting capabilities. Examples include: Customer onboarding analytics KYC completion/pending Customer activity and retention AUM and AUM growth SIP book and growth Product popularity Product-wise AUM Subscription trends Historical portfolio analysis Monthly/quarterly/yearly/FY analysis Distributor performance Product trends Custom date-range comparisons Customer/distributor/admin reports PDF/Excel exports External Integrations Potential integrations include: CAMS NSE BSE KYC/CKYC providers PAN verification eKYC Payment gateway SMS Email WhatsApp Licensed market/product-data providers Actual integrations will depend on API documentation, commercial agreements, credentials, sandbox access and required approvals. Cloud & DevOps The proposed infrastructure includes: Docker GitHub Actions DigitalOcean Managed PostgreSQL Redis DigitalOcean Spaces VPC Firewall Container Registry Load Balancer Cloudflare Prometheus Grafana Loki The project will have separate development, staging and production environments with automated CI/CD, monitoring, backups and disaster recovery procedures. Security Requirements Security is a major component of this project. The developer should have practical experience with: JWT/refresh-token authentication MFA/OTP RBAC Multi-tenant data isolation API security Encryption Rate limiting Secrets management Private networking Firewall configuration Audit logging Secure data export Financial transaction security The backend must enforce authorization and ensure that one distributor cannot access another distributor's customers or data. Testing & Performance The system will require: Unit testing API testing Integration testing Regression testing Performance testing Security testing UAT support Load/stress testing Initial capacity target is approximately 200 concurrent users, with final production sizing to be determined through performance testing. Ideal Candidate We are looking for someone who has real-world experience building production FinTech, wealth-management, investment, banking, payment or other financial applications. Strong experience in the following areas is preferred: 7+ years of software development Senior-level Node.js/TypeScript experience NestJS React/Next.js PostgreSQL Redis Python Airflow Data pipelines / ETL ClickHouse or another analytical database REST API architecture Third-party API integrations Cloud infrastructure Docker CI/CD Security and RBAC Multi-tenant SaaS architecture Experience with Mutual Funds, SIP, portfolio management, KYC, brokerage, wealth management, payments or investment platforms will be a significant advantage. We are open to your recommendations and would prefer the best practical technology/architecture for the project rather than blindly following a predefined stack. Please Answer These Questions in Your Proposal Please describe your most recent FinTech/financial-services project. What was the business domain, your role, team size and technology stack? Have you previously built a Mutual Fund, SIP, wealth-management, portfolio-management, brokerage or investment platform? Please explain exactly what you built. Have you integrated with CAMS, NSE, BSE, KFintech, CKYC, PAN/KYC providers or similar financial APIs? Please specify which APIs and what functionality you implemented. Please provide 2–3 relevant production projects that demonstrate your experience. Include links/screenshots where confidentiality permits. Have you implemented multi-tenant B2B SaaS architecture where each distributor/tenant can only access its own customers and data? Explain your approach to tenant isolation. Have you designed systems using PostgreSQL + ClickHouse or another OLTP + analytical database architecture? How did you synchronize transactional data with the analytical layer? What experience do you have with Python + Apache Airflow? Please describe one real ETL/data pipeline you implemented. Have you handled financial transaction processing and reconciliation? If yes, explain how you handled transaction status, callbacks/webhooks, failures, idempotency and reconciliation. What approach would you use to ensure financial calculations such as XIRR, CAGR, SIP returns and portfolio P&L are accurate and auditable? What is your experience with RBAC, data security, audit trails and sensitive financial/customer data? Have you implemented CI/CD and production infrastructure on DigitalOcean, AWS, Azure or GCP? Please describe the architecture. What monitoring/logging tools have you used? Have you worked with Prometheus, Grafana and Loki? How would you design this system to scale from approximately 200 concurrent users to 5,000–10,000+ users without a major architectural rewrite? What would you identify as the three biggest technical risks in this project? If you were responsible for the architecture, what would you change or improve in our proposed technology stack and why? How would you approach integration when an external financial provider has limited APIs, unreliable APIs, delayed callbacks or incomplete documentation? Please provide your availability per week, expected project duration and preferred engagement model. What part of this project do you consider your strongest area, and which part would you prefer another specialist to handle? Important We are looking for someone who can contribute beyond writing code. The selected developer should be capable of understanding the financial domain, challenging architectural decisions when necessary, designing scalable solutions and taking ownership of production implementation. Please do not submit a generic proposal. Your proposal should specifically address the questions above and demonstrate relevant experience with FinTech, financial data, investment platforms, portfolio management, KYC, analytics and secure financial systems.