Rizon Kumar Rahirizon__kumar

Architected a multi-tenant, enterprise-grade SaaS platform that helps software engineers prepare for interviews. It is a Turborepo + pnpm monorepo with a NestJS backend organized into 19 domain modules following strict Domain-Driven Design + Clean Architecture (Domain → Application → Infrastructure → Presentation). Two Next.js 16 (App Router) frontends sit on top of it: a candidate portal and an independently deployable Super-Admin backoffice, both served behind a single origin. The centerpiece is a harness-based, Dockerized code-execution sandbox that grades DSA submissions across JavaScript, Python, and C++ in isolated containers, with a synchronous run path and a BullMQ-queued submit path. Around that sandbox sits a 2,700+ problem bank, daily challenges with solving streaks, timed coding contests, achievement badges, an in-app notification center, spaced-repetition review, per-problem discussions/bookmarks/notes/lists, a Kanban job tracker, community forums with moderation, and timeframe leaderboards. Underpinning all of it are RBAC, JWT access/refresh rotation, feature flags, and immutable audit logging for SOC 2 / ISO 27001 compliance.

A personal finance workspace built on Next.js 16 (App Router, React 19), with the entire backend living in the same deployable. A Hono app is mounted on a catch-all route handler, and its fluent chain exports an AppType, so the frontend gets a fully typed RPC client through hc<AppType>() with zero codegen. Types run end to end without a single hand-written DTO. The Drizzle schema is the single source of truth, drizzle-zod derives the validators from it, and those same Zod schemas back the react-hook-form resolvers, so changing a column surfaces as a compile error in the component that renders it. Twelve feature modules cover accounts across nine types (savings, cash, wallet, investment, fixed deposit, PPF, EPF, credit and loan), transactions with CSV import and bulk operations, categories, budgets over four period types, savings goals with a contribution ledger, debt payoff with snowball versus avalanche projection, transfers, a holdings and trade ledger with weighted-average cost, a balance forecast, and a command palette. Two design decisions carry most of the weight. Recurring transactions materialise lazily on read rather than through a cron or a queue, so a monthly SIP or a loan EMI enters itself with no extra infrastructure. And net worth is computed from real account balances as of any date rather than inferred from cash flow, which keeps assets, liabilities and the daily trend honest. Every colour is a CSS variable on a Geist-derived OKLCH scale, so Recharts themes with the app across light and dark.