MohsenMirzaei

Jul 2026 – Nov 2026

Alexander's Antiques

Lead Full-Stack Engineer · Freelance

Built a Manhattan gallery's own platform end to end — Next.js storefront, Vite staff workbench, and NestJS API — and launched it at alexanderantiques.com with 939 pieces migrated from 1stDibs.

• Delivered ~130K LOC across storefront, admin, and a 138-route NestJS API, authoring 89% of commits behind a 4,300+ test quality gate.
• Shipped both apps on fixtures first, then cut over to the API through 16 repository ports; a parity suite proved all 83 methods before launch.
• Ran a report-first 1stDibs migration of 917 pieces into a four-level, 124-category taxonomy — idempotent, and refusing to write on a count mismatch.
• Built inquiry-not-checkout selling: phone-OTP collectors, six inquiry types, two-way threads with images, and staff letters logged with their trace.

Apr 2026 – Oct 2026

Smart School · Maktabsoft

Lead Frontend Engineer · Freelance

Rebuilt a school platform's mobile app from zero — one React codebase serving students and teachers on the web, as a PWA, and on Android, replacing an app with 180,000 installs.

• Architected a 60K LOC feature-sliced app where the router assigns the role: 20 live student and teacher sections, frozen student URLs, no role branching in UI.
• Wrapped 99 legacy backend methods with 69 typed mappers and a ranked contract-exceptions record, where live probes overrode wrong documentation.
• Shipped silent auto-update across web, PWA, and a Capacitor Android shell, so web deploys reach Android with no store release.
• Built adaptive motion — a frame-rate probe assigns full, lite, or minimal per device — with 587 tests across mappers, hooks, and stores.

Sep 2025 – Mar 2026

Restaurant Reservation Platform

Full-Stack Engineer · Freelance, Part-Time

US-client reservation platform unifying event hall, catering, and table bookings into a 4-app monorepo with self-service booking flows and production observability.

• Unified 3 booking channels into a 4-app monorepo with 21 customer/admin screens, replacing phone-based intake with self-service flows.
• Designed the reservation core — an 8-state lifecycle with transactional slot locking — preventing double-bookings and invalid transitions.
• Enforced single-source API contracts via 77 shared Zod schemas and 72 automated tests across auth, booking, and audit paths.
• Set up async BullMQ notifications (Twilio/Resend) off the HTTP path and a 9-service observability stack targeting p95 <500 ms.

Aug 2025 – Apr 2026

RcoinX

Senior Frontend Software Engineer

Architected the frontend platform for a pre-launch crypto exchange, from monorepo foundations to real-time Spot Trading and account-security flows.

• Architected the frontend from scratch — Turborepo monorepo with 8 shared packages and strict Feature-Sliced Design import boundaries — authoring 61% of commits in a 3-engineer team.
• Delivered Spot Trading end-to-end (~9.5K LOC): order book, charts, order management, 9 REST integrations, and 3 WebSocket streams.
• Built a centralized WebSocket layer with ref-counted subscriptions, auto-reconnect, and 200–300ms throttled cache patching for market data.
• Shipped Account & Security with TOTP, WebAuthn, MFA-gated flows, RTL/LTR Storybook components, and Vitest + MSW tests in Docker CI.

Apr 2025 – Jul 2025

Isopoll

Frontend Software Engineer

Frontend engineer on a fully RTL Persian B2B SaaS platform spanning surveys, recruitment, consultation booking, and digital commerce.

• Engineered a 35K+ LOC, 41-page Next.js enterprise platform across 6 business modules in 4 months.
• Structured the data layer with 85 React Query hooks, 86 typed services, and 18 API domains, cutting new-endpoint work to one hook.
• Standardized 23+ production forms on 41+ Zod schemas, with hybrid SSR and tag-based revalidation across 31+ modules.

Apr 2025 – Jul 2025

Propx

Frontend Engineer · Freelance, Part-Time

Bilingual hedge fund platform — multi-step KYC onboarding, role-based dashboards, and a support ticketing system for customer verification workflows.

• Developed an 11-step KYC wizard with in-browser ID capture and video recording, completed in a single web session.
• Delivered 18 role-gated screens across public, user, and super-admin areas, integrating the API through 30 typed hooks.
• Implemented a bilingual EN/FA interface with 633 strings in each language and 6 Zod-validated forms shared across auth, KYC, and ticket flows.

Oct 2024 – Mar 2025

Chatomatic

Co-Founder & Full-Stack Engineer

Co-founded and launched an AI assistant SaaS, then rebuilt the platform end-to-end with dashboard, playground, RAG retrieval, and a Shadow DOM embed.

• Co-founded and launched to 100+ users; rebuilt it end-to-end solo in 2026 (~25K LOC) across dashboard, playground, and Shadow DOM embed.
• Built a greenfield Fastify API with 7 modules, 27 Result-typed use-cases, 11 tables, public embed routes, and per-assistant OpenAI/Ollama routing.
• Designed 2-phase streaming chat: pgvector top-5 retrieval, token stream, then post-stream citation persistence.
• Implemented hybrid RAG: IVFFlat top-5 retrieval with full-context fallback, inline numbered citations, and a 5-format ingestion pipeline.

Feb 2024 – Sep 2024

IT Barbod

Full-Stack Engineer

Led frontend delivery across three products in an on-site product team — a no-code app builder, a full-stack form builder, and an RTL markdown editor.

• Built a drag-and-drop app builder enabling non-technical teams to ship React Native screens without engineering, cutting screen delivery from multi-day dev cycles to hours.
• Architected an RTL-first Markdown editor on Monaco with 24+ authoring commands.
• Created a schema-driven UI system with a Draft → Merge → Publish → Rollback lifecycle and a form builder with 11 field types on Next.js, Prisma, and PostgreSQL.

2023 – 2024

HeidaryHa

Frontend Engineer · Contract

Mobile banking PWA serving 14,000+ customers, with multi-factor auth and high-reliability financial transaction workflows.

• Launched a production mobile-banking PWA serving 14,000+ customers, building its authentication and transaction flows.
• Contributed to a 40% increase in monthly loan applications, shipping PWA + Android from a single React/TypeScript codebase.

2021 – 2023

Motion Desk

Software Engineer

Collaborated with motion and product designers to build and publish two commercial Adobe After Effects extensions on aescripts.com.

• Shipped 2 commercial cross-platform After Effects (CEP) extensions on aescripts.com.
• Reached 3,000+ downloads and 1,000+ sales by translating designer workflows into optimized extension UIs.