Senior Full-Stack DeveloperBuilding Scalable Solutions

Architecting and delivering high-performance web applications with measurable business impact. Specialized in React, Next.js, Node.js, Python, and AWS, with a proven track record of reducing latency by 84%, improving conversions by 28%, and processing 500K+ records/min.

Key Achievements

84%
Latency Reduction
p95 from 1,200ms to 187ms
28%
Conversion Improvement
Through UX optimization
500K
Records/Min Processing
Real-time analytics pipeline
1.2M
Monthly Active Users
Served at scale

About Me

Senior Full-Stack Developer with extensive experience building scalable, user-centric web applications. I specialize in architecting robust systems that deliver measurable business impact through performance optimization, modern development practices, and cloud-native solutions.

My expertise spans the entire stack—from crafting responsive React/Next.js frontends to building high-throughput Node.js/Python backends, implementing event-driven architectures, and optimizing cloud infrastructure on AWS and GCP.

I'm passionate about engineering excellence, championing comprehensive testing strategies (95% unit, 85% E2E coverage), observability with OpenTelemetry and Prometheus, and infrastructure-as-code with Terraform to ensure reliability and maintainability.

Core Competencies

  • Full-stack development with React, Next.js, Node.js, and Python
  • System architecture and microservices design
  • Cloud infrastructure (AWS, GCP) and DevOps practices
  • Performance optimization and scalability engineering
  • Testing strategies and quality assurance (Jest, Playwright, Pytest)
  • API design (GraphQL, REST) and real-time systems (WebSockets)

Experience

Senior Full-Stack Developer

Webxkey
Oct 2024 – Present
Onsite, Sri Lanka

Platform Architecture & Performance

Architected multi-tenant, event-driven SaaS platform serving 1.2M MAU using React, Next.js 14, and Node.js microservices on AWS EKS with SQS, Lambda, RDS Aurora, and ElastiCache Redis.

84% latency reduction (1,200ms → 187ms)62% error rate reduction28% conversion improvement

Data Engineering & Analytics

Developed Python-based real-time data processing pipeline using FastAPI and Pandas, processing 500K records/min with 99.8% accuracy and reducing dashboard refresh times by 45%.

500K records/min throughput99.8% accuracy

Quality Engineering & Testing

Migrated 12 Node.js services to TypeScript and implemented comprehensive testing pyramid with Jest (95% unit), Playwright (85% E2E), Pact (contract tests), and Pytest (90% coverage).

92% code coverage73% fewer production regressions

Technology Stack:

TypeScriptReactNext.js 14Node.jsPythonFastAPIAWS EKSLambdaSQSRDS AuroraRedisJestPlaywrightPytest

Full-Stack Developer

FoxIO
Oct 2020 – Jun 2024
Remote, US

API Architecture & Integration

Built GraphQL Federation layer over 18 legacy REST microservices using Apollo Server, enabling typed client queries and reducing frontend network roundtrips by 67% (from 14 to 4 calls per page).

67% fewer network calls18 services unified

Performance Optimization & SEO

Implemented Next.js ISR with Vercel Edge Network and React Server Components, improving Largest Contentful Paint by 45% and increasing organic search traffic by 38% within 3 months.

45% LCP improvement38% organic traffic increase

Real-time Collaboration & Scalability

Built real-time collaboration features using AWS AppSync GraphQL subscriptions and WebSocket connections, supporting 15K concurrent users with 99.97% uptime.

15K concurrent users99.97% uptime

Experimentation & Feature Management

Designed LaunchDarkly feature flag system with custom experiment framework, enabling 24 A/B tests per quarter across checkout, pricing, and onboarding flows with <0.1% false positive rate.

Technology Stack:

GraphQLApollo ServerNext.jsReactNode.jsPythonDjangoCeleryAWS AppSyncWebSocketsLaunchDarklyVercel

Featured Projects

Antique Arena Auction Platform

antiquearena.com →

Real-time auction platform supporting 100+ auctions annually for thousands of concurrent users with 99.9% uptime. Features dynamic auction listings, scheduling, and real-time bidding.

Built with React, Next.js, TypeScript, Node.js, and MongoDB
Redis caching and MongoDB indexing for 30% faster page loads
GraphQL APIs with AWS SES integration for 15% retention boost
Full observability with OpenTelemetry, Prometheus, and Grafana
CI/CD with GitHub Actions and Terraform for zero-downtime deployments
ReactNext.jsTypeScriptNode.jsMongoDBRedisGraphQLAWS SESOpenTelemetryTerraform

Business Management System

Luxury Watch Retailer | Webxkey

Comprehensive business management platform handling 5,000 daily transactions with sub-200ms response times and 99.95% availability for a luxury watch retailer.

Built with React, Next.js, Tailwind CSS, Node.js, NestJS, PostgreSQL
Kafka for event streaming and Redis for caching
Real-time dashboards improving operational productivity by 30%
Secure GraphQL and REST APIs with Stripe and ERP integration
Python ETL pipeline processing 10TB data, 40% faster ingestion
ReactNext.jsNestJSPostgreSQLKafkaRedisGraphQLPythonPandasAirflowDocker

Technical Skills

Languages

JavaScript / TypeScript
Python
SQL
HTML5 / CSS3

Frontend

React.js
Next.js (App Router, ISR)
Redux / Zustand
Tailwind CSS
Server Components
Responsive Design

Backend

Node.js / Express
Python / FastAPI / Django
GraphQL / Apollo Server
REST APIs
WebSockets
Microservices

Databases & Caching

PostgreSQL / MySQL
MongoDB
Redis / ElastiCache
Google BigQuery
RDS Aurora
Database Optimization

Cloud & DevOps

AWS (EKS, Lambda, SQS, S3, RDS)
Google Cloud Platform
Docker & Kubernetes
Terraform (IaC)
GitHub Actions CI/CD
Vercel Deployment

Testing & Observability

Jest / Vitest (Unit Testing)
Playwright (E2E Testing)
Pytest (Python Testing)
Pact (Contract Testing)
OpenTelemetry
Prometheus & Grafana

Data & Messaging

Apache Kafka
AWS SQS
Google Pub/Sub
RabbitMQ
Pandas / NumPy
ETL Pipelines

Architecture & Practices

System Design
Event-Driven Architecture
API Design (REST, GraphQL)
Performance Optimization
Security Best Practices
Agile / Scrum

Tools & Platforms

Git / GitHub
Postman / Insomnia
LaunchDarkly
Stripe Integration
AWS AppSync
VS Code

Education

Bachelor of Engineering

London Metropolitan University
Computer Software Engineering

BSc in MIT

South Eastern University of Sri Lanka
Computer Science

Let's Work Together

I'm always interested in hearing about new opportunities, challenging projects, and innovative teams. Let's connect!

Phone: +94 75 903 7101

WhatsApp: +94 78 284 3470

Email: maleensaman@gmail.com

Location: Vavuniya, Northern Province, Sri Lanka