Mohd. Hussain Ansari
Software Development Engineer 2 · Back-end Engineering
Real-time systems, payments, and the boring parts of money.
- Location
- Mumbai, Maharashtra, India
- Experience
- 4+ years
- Currently
- INK IN CAPS
- Contact
- mohd.hussainansari19@gmail.com
01 / Signals
02 / Profile
What I actually do
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.
Core competencies
- Back-end development & architecture
- Distributed & event-driven systems
- Real-time infrastructure
- API, webhook & third-party integration
- Payment & subscription lifecycle
- Database design & performance
- Multi-tenant platform engineering
- Wallet, ledger & transaction processing
- Cloud infrastructure (AWS)
- Background jobs & async workflows
- Production reliability engineering
- Code review, mentoring & ownership
- Stakeholder engagement
03 / Selected Work
Systems I've built and run
Five production systems — real-time infrastructure, payments and ledgers, a national commerce protocol, and an app built to work with no network at all. Each entry links to the architecture behind it.
04 / Experience
Where I've worked
Software Development Engineer 2
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)
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.
05 / Stack
What I build with
06 / Recognition
Awards, education & certs
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
07 / Contact
Let's talk
Open to back-end engineering roles, consulting, and interesting product conversations.