Technical Assessment · Completed · Solo ProjectTechnical Assessment
FinTech Core API
Transaction APIs with mutex locking, idempotency protection, and auditability — built as a backend engineering assessment.
Node.jsExpressPostgreSQL
2 min read
Backend Engineer
Hi, I'm Lakshay
Building APIs, authentication systems, and payment workflows with Node.js & AWS
Introduction
Hi, I'm Lakshay — a Backend Engineer focused on building reliable systems.
I specialize in authentication architecture, payment integration, and event-driven services using Node.js, Express, MongoDB, and AWS.
What I Work On
- Payment security and transaction processing
- Authentication system reliability
- Asynchronous workflow design
- Database architecture and optimization
My approach: understand the root cause, design clear architecture, implement with proper observability.
Top Projects
Engineering case studies — technical decisions, tradeoffs, and debugging stories.
Personal Tool · Active · Solo ProjectActive Project
Resource Hub
Centralized platform for managing resource links with pre-signed URL uploads and Auth Service integration.
Node.jsExpressMongoDB
1 min read
Personal Tool · Active · Solo ProjectActive Project
Auth Service
Centralized authentication service with asymmetric JWT, local token verification, and async email delivery via AWS.
ExpressMongoDBAWS SNS
3 min read
Personal Tool · Active · Solo ProjectActive Project
IdeaHub
Centralized platform for capturing product ideas and thoughts, with soft delete and Auth Service integration.
Next.jsDrizzle ORMPostgreSQL
3 min read
Experience
Where I've applied backend engineering in production.
Backend Engineer
InternWare
Backend systems powering event registration platforms, authentication, payment workflows, and administrative tooling for real users.
At InternWare, I worked on authentication, payment workflows, coupon management, and admin tooling for production event-registration systems handling real users and transactions.
Read full experience →Skills & Technologies
Backend Development
Node.jsExpress.jsMongoDBREST APIsJWTOAuth 2.0WebhooksCashfree
Cloud & AWS
LambdaSQSSNSCloudWatchIAM
DevOps & Deployment
DockerGitHub ActionsLinux
Development Tools
GitPostmanESLint
Latest Articles
Technical insights on web security, authentication, and modern software engineering
PaymentsArchitecture
Payment Architecture Evolution: From Client-Side Risks to Reliable Webhooks
How payment gateway architecture evolves from insecure client-side flows to server-side order creation, webhooks, and reconciliation — and how we applied it at Internware.
4 min read
Applied AIAI Engineering
My Evolution Towards Becoming an Applied AI Engineer
Reflections from building my first AI application and learning what it really takes to ship production-ready AI — guardrails, human-in-the-loop, context management, and the difference between SDKs and Agent SDKs.
3 min read
AuthenticationJWT
Access and Refresh Tokens: A Practical Guide
Learn why single long-lived tokens create UX and security problems, how access and refresh tokens solve them, and the key implementation decisions you need to make.
3 min read
Contact
Open to Backend Engineer opportunities in authentication infrastructure, payment systems, or distributed services. Reach out via email or connect on social platforms.
dev@lakshaymahajan.com