Mohd. Hussain Ansari

Software Development Engineer 2 · Back-end Engineering

Mumbai, Maharashtra, India · mohd.hussainansari19@gmail.com · linkedin.com/in/mohd-hussain-ansari · github.com/Mohd-Hussain-Ansari · hussainansari.dev

At a glance

Looking for
SDE 3, Senior Backend Engineer, Backend Engineer
Availability
30-day notice period
Work mode
Mumbai (on-site / hybrid) or remote
Experience
4+ years; currently Software Development Engineer 2 at INK IN CAPS
Core stack
Node.js, NestJS, TypeScript, MongoDB, PostgreSQL, Redis, AWS

Summary

Back-end engineer with over four years designing and running production systems in Node.js, NestJS and TypeScript. My work sits where correctness matters most: payment and subscription lifecycles, wallet and ledger mechanics, and real-time infrastructure that has to stay consistent across many servers at once.

  • I design real-time WebSocket infrastructure on Socket.IO and Redis Pub/Sub, fanned out across multiple servers, currently carrying 3,000+ concurrent connections for messaging and notifications.
  • I work on payment and transaction processing — gateway workflows moving roughly $462K USD a month across about 7,700 transactions for 30K+ users, alongside subscription lifecycle, idempotency, retry, wallet and ledger functionality.
  • I take ownership of performance and migrations: 800+ sellers moved with zero data loss, schema and indexing reworked across 2.7 million records, and a 25% improvement in query latency.
  • I have led a 10-member cross-functional team of back-end and QA engineers, running requirement gathering, feature discussion, and product demos with founders and clients across London, Dubai and Canada.

Experience

Software Development Engineer 2 — INK IN CAPS

Dec 2025 — Present · Mumbai

Back-end engineering on a creator subscription platform: real-time messaging infrastructure, the subscription and wallet money paths, and the async job layer behind them.

  • Designing real-time WebSocket infrastructure on Socket.IO and Redis Pub/Sub across multiple servers for live messaging and notifications.
  • Managing the end-to-end subscription lifecycle — activation, renewal, expiry, invoicing, retries and failure recovery — with idempotency mechanisms that prevent duplicate charges.
  • Building wallet and ledger functionality for credit, debit and balance tracking with atomic, consistent transactions.
  • Running Redis-backed BullMQ queues so renewals, notifications and invoicing happen outside the request path.
  • Developing signature-validated webhooks and push notification pipelines on AWS EC2, ALB, Route 53, Lambda, SES and S3.
  • Redesigned a slow home-feed endpoint, cutting load time by ~75% and data transfer by up to 90% under typical usage.

Product Developer (Back-end) — AppOctet Technologies

May 2022 — Oct 2025 · Mumbai

Progressed from mobile app developer to product developer — shipping React Native apps before taking ownership of back-end architecture, third-party integrations, code review, mentoring, and production releases across several products.

  • Led back-end development across product engagements, owning architecture, reusable APIs, integrations, reviews, mentoring, production systems and releases.
  • Drove back-end reliability by identifying recurring failure scenarios and strengthening error handling across production applications.
  • Improved deployment through Docker-based automation — deploys following code push and a green test run, with less manual intervention.
  • Led the technical migration of 800+ sellers with zero data loss, and optimised schema and indexing across ~2.7 million records for a 25% query latency improvement.
  • Recognised as Star Performer in both 2024 and 2025.

Selected projects

  • Creator Subscription & Wallet Platform (INK IN CAPS, Dec 2025 — Present): Real-time messaging, subscription lifecycles, and a multi-provider wallet and ledger, run across a horizontally scaled NestJS monorepo. Outcomes: 3,000+ concurrent WebSocket connections; $462K/mo processed across ~7,700 transactions; 30K+ users served; −75% home-feed load time; −90% home-feed payload size.
  • Multi-Tenant Seller Marketplace (AppOctet Technologies, 2022 — 2025): Seller operations, order management, and Shopify synchronisation for a multi-tenant marketplace, rebuilt on NestJS with a migration of 800+ sellers and zero data loss. Outcomes: 800+ sellers migrated, zero data loss; 2.7M records re-indexed; −25% query latency.
  • Events & Booking Platform (AppOctet Technologies, 2022 — 2025): Event creation, participant management, and payouts for a bookings platform, with identity verification and real-time admin alerting. Outcomes: −40% admin response time; 5 notification channels from one backend; 3 clients served: web, native, admin.
  • ONDC Logistics Network Integration (AppOctet Technologies, 2022 — 2025): Protocol-compliant order, fulfillment, and grievance APIs certifying a logistics provider onto India's Open Network for Digital Commerce. Outcomes: 5+ partner organisations certified; 16 protocol services across 4 domains; 100% of order lifecycle stages audited.
  • Offline-First Rider App (AppOctet Technologies, 2022 — 2025): A React Native delivery app for riders working without reliable connectivity, built on a local SQLite source of truth and a sync engine that routes each shipment by type and outcome. Outcomes: 100% of a shift capturable offline; 4 shipment flows, 8 settlement routes; 4 locales shipped.

Skills

Languages
TypeScript, JavaScript (ES6+), Java
Runtime & Frameworks
Node.js, NestJS, Express.js
Data
MongoDB, MySQL, PostgreSQL, Redis, Mongoose, TypeORM, Prisma
Async & Real-Time
BullMQ, Redis Pub/Sub, Socket.IO, WebSockets, Agenda, Delayed jobs, Retry strategies
Cloud & Infra
AWS EC2, ALB, Route 53, Lambda, SES, SQS, S3, CloudFront, Docker, Git
Architecture
REST APIs, Webhooks & signature validation, Event-driven systems, Idempotency & retries, Wallet & ledger design, Subscription lifecycle, RBAC / CASL policies
Integrations
Razorpay, Cashfree, Centrobill, Shopify, Onfido, Delhivery, Shiprocket, ONDC, Firebase, WhatsApp API, Slack
Testing & Observability
Jest, Supertest, OpenTelemetry, Signoz, New Relic, Winston, Pino, Swagger
AI-Assisted Development
Claude, GitHub Copilot, ChatGPT

Achievements

  • Star Performer — 2024 & 2025, AppOctet Technologies. Recognised in consecutive years for product delivery and back-end performance work.
  • First Rank — B.Sc. Computer Science, Mumbai University. Graduated first in the Computer Science programme at Ismail Yusuf College.
  • ONDC Network Certification, Open Network for Digital Commerce. Led a logistics integration through ONDC protocol certification with 5+ partner organisations.

Education

  • B.Sc. Computer Science, Ismail Yusuf College, Mumbai University (2019 — 2022). First Rank.

Certifications

  • Generative AI Mastermind, OutSkill
  • Problem Solving (Basic), HackerRank
  • Algorithm Essentials, HackerRank
  • AI Tools Workshop, Be10x