Senior Software Engineer | Fortunate Partners
Jan 2026 - Apr 2026 | Full-timeDelivered RoundUp end-to-end - a regulated real-money digital lottery platform spanning five game types (round-up, instant-win, mega-jackpot, mystery-box, and subscription draws) across user-web, admin, kiosk, and mobile channels.
- Architected a 29-module NestJS 11 backend (32 TypeORM/PostgreSQL entities) split into five purpose-built AWS Lambdas - API, async processing, notifications, webhooks, migrations - for independent scaling and deploys.
- Engineered an event-driven draw lifecycle (EventBridge + SQS) that keeps exactly one draw open at a time and auto-allocates prizes on close - eliminating manual draw operations.
- Authored lpfy, a zero-dependency Lazy Partial Fisher-Yates library for CSPRNG-backed winner selection with rejection sampling to eliminate modulo bias, in O(m) memory across billion-scale ranges.
- Shipped three React 19 clients (player, admin, kiosk-operator) on Vite/Tailwind 4/Zustand/TanStack Query, plus a React Native app (RN 0.79) with biometric auth, QR scanning, and push.
- Hardened the platform for regulated real-money play - AML/KYC, MFA (SMS/Email OTP + TOTP), play/deposit/session limits, and six-role RBAC via AWS Cognito.
- Integrated Stripe payments/webhooks with the internal wallet, plus Firebase push, SendGrid email, and QR kiosk cash-in.
- Provisioned multi-region AWS (eu-west-1/2, us-east-1) from 22 reusable Terraform modules across 58 Terragrunt stacks; guarded by SonarQube static analysis and 110+ Playwright end-to-end test cases with Mailosaur OTP verification.
Projects: RoundUp - Digital Lottery & Gaming Platform
Stack: NestJS 11, TypeScript, TypeORM, PostgreSQL (Aurora), Stripe, AWS (Lambda, Aurora RDS, S3, CloudFront, Cognito, SQS, KMS, Secrets Manager, SES, EventBridge), Terraform, Terragrunt, React 19, Vite, Tailwind CSS 4, Zustand, TanStack Query, Radix UI, React Native 0.79, Firebase, SendGrid, OpenAPI (Orval-generated typed clients), Playwright, Mailosaur, accessibility testing (axe-core), Lighthouse CI, Sentry, Jest, lpfy