Ahmed Kamel
Backend Developer | Oct 2024 - Present
- About E-VasTel
- My Role & Responsibilities
- Technical Skills & Technologies
- Projects & Products
- Overall Impact Summary
- Notes
E-VasTel is a leading software services provider delivering high-quality IT solutions for enterprise-level clients as well as small to medium organizations. With over 10 years of industry experience, E-VasTel focuses on enabling organizations to stay competitive in a rapidly evolving digital landscape.
The company highlights a strong record of success and a broad portfolio of services spanning cybersecurity, networking, business applications, and more.
Duration: Oct 2024 - Present | 1 year 2 months
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System Architecture & Design: Designed and implemented secure, maintainable, and high-performance backend systems.
- Developed a complete cloud platform from scratch, integrating multiple external tools and third-party services.
- Led the migration of a monolithic application to a microservices architecture, making key architectural decisions.
- Ensured system scalability, reliability, and security through best practices, design patterns, and sound architectural principles.
- Evaluated and selected the most suitable technologies and tools for projects, making decisions based on performance, scalability, and maintainability.
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Team Mentorship & Leadership: Guided junior developers through code reviews, knowledge sharing, and best practice enforcement.
- Collaborated with team members across different functions to deliver projects effectively.
- Worked closely with infrastructure engineers to build and maintain the cloud platform.
- Mentored junior developers by providing guidance, code reviews, and knowledge sharing.
- JavaScript, TypeScript
- Node.js, NestJS, Express.js, Fastify
- REST API, GraphQL, gRPC
- MySQL, PostgreSQL
- MongoDB
- Redis
- Apache Kafka
- Outbox Pattern
- Distributed Transactions
- Event-Driven Architecture
- Microservices Architecture
- Clean Architecture
- Repository Pattern, Unit of Work Pattern
- Design Patterns, Architecture Patterns
- Monorepo Architecture
- Third-Party Integrations
- JWT Authentication
- RBAC (Role-Based Access Control)
- Docker
- Git, GitLab
Role: Lead Backend Engineer Duration: + 1 year Team Size: 2 members
Overview: Sky Gate Cloud is a distributed cloud management platform offered as both a public SaaS for individual users and a private/on-premise solution for enterprise datacenters. It provides secure user management, integrations, operational automation, and multi-tenant capabilities built for high reliability and scalability.
My Contributions:
- Designed and built the entire backend ecosystem and core services from scratch.
- Migrated the system from a monolith to a microservices-based architecture aligned by business domains.
- Designed a deployment model supporting public cloud hosting and self-hosted datacenter installations.
- Implemented multi-tenant authentication, RBAC, and access control layers.
- Mentored a junior developer and enforced clean code, architectural patterns, and best practices.
Technical Implementation:
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Architecture:
- Distributed microservices running inside a NestJS monorepo, each following Clean Architecture.
- Clear separation of domain, application, and infrastructure layers.
- Applied CQRS where appropriate for performance and scalability.
- Implemented Repository and Unit of Work patterns for domain-driven persistence.
- Supported both SaaS and private/on-prem deployments with environment-driven configurations.
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Inter-Service Communication:
- gRPC for synchronous, strongly-typed communication.
- Kafka for asynchronous event streaming and distributed workflows.
- Enforced secure inter-service communication with JWT service tokens.
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Data & Consistency:
- Outbox Pattern to ensure reliable event publishing.
- Transaction management using Unit of Work + DB transactions.
- Distributed transaction safety handled through event choreography, sagas, and idempotency.
- Optimized SQL queries with functions, triggers, and materialized views.
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Caching & Performance:
- Redis for caching, rate-limiting, and precomputed usage metrics.
- Caching read-heavy GraphQL resolvers and cross-service computed fields.
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API Layer & Federation:
- Used Mercurius Federation for GraphQL at the API Gateway.
- Separate GraphQL schemas for admin vs user operations.
- Queries/mutations mapped to CQRS commands and domain-driven services.
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Services Implementation:
- Each microservice contains its own domain, repositories, migrations, and gRPC interfaces.
- Shared libraries for DTOs, configurations, helpers, and common domain contracts.
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Background Tasks:
- Scheduled jobs for cleanup, metrics calculation, periodic events, and synchronization.
Impact & Results:
- Enabled both public SaaS and private on-premise deployments, expanding product reach.
- Improved maintainability and scalability through microservices and Clean Architecture.
- Achieved high reliability with event-driven pipelines and outbox-based consistency.
- Reduced operational overhead with caching, optimized DB queries, and distributed processing.
Technical Highlights:
- Clean Architecture + Repository Pattern + Unit of Work
- Kafka + Outbox Pattern for reliable event publishing
- gRPC microservices with secure JWT-based communication
- Redis caching layer for performance and aggregated metrics
- GraphQL Federation via Mercurius
- Distributed transactions using event choreography and idempotent workflows
- Fully supported public SaaS and private/on-prem installations
- Self-hosted NPM registry for sharing internal packages across all services
- ~2 projects delivered successfully
- ~5 team members collaborated with
- ~2 years of experience gained
- +10 features launched
- All information shared here respects confidentiality agreements and NDAs
- Specific client names and sensitive technical details are omitted where appropriate
- This documentation represents my personal experience and contributions
Thank you for taking the time to learn about my journey at E-VasTel!
Last Updated: Nov 2025