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I'm a seasoned Full Stack Engineer with 7+ years of experience building scalable web applications. I design intuitive front-end experiences using React and JavaScript, and I build robust back-end services with Python and microservices. I enjoy collaborating with remote teams, applying Kanban and Agile practices to deliver value incrementally. I'm passionate about AdTech and cloud-native architectures, focusing on reliability, security, and performance. I thrive in fast-paced environments and love mentoring teammates to grow their skills and share knowledge across distributed teams.…I'm a seasoned Full Stack Engineer with 7+ years of experience building scalable web applications. I design intuitive front-end experiences using React and JavaScript, and I build robust back-end services with Python and microservices. I enjoy collaborating with remote teams, applying Kanban and Agile practices to deliver value incrementally. I'm passionate about AdTech and cloud-native architectures, focusing on reliability, security, and performance. I thrive in fast-paced environments and love mentoring teammates to grow their skills and share knowledge across distributed teams.

Zeynal Calis

Back-End Developer, Full Stack Developer, Web Developer, +3

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I'm a seasoned Full Stack Engineer with 7+ years of experience building scalable web applications. I design intuitive front-end experiences using React and JavaScript, and I build robust back-end services with Python and microservices. I enjoy collaborating with remote teams, applying Kanban and Agile practices to deliver value incrementally. I'm passionate about AdTech and cloud-native architectures, focusing on reliability, security, and performance. I thrive in fast-paced environments and love mentoring teammates to grow their skills and share knowledge across distributed teams.…I'm a seasoned Full Stack Engineer with 7+ years of experience building scalable web applications. I design intuitive front-end experiences using React and JavaScript, and I build robust back-end services with Python and microservices. I enjoy collaborating with remote teams, applying Kanban and Agile practices to deliver value incrementally. I'm passionate about AdTech and cloud-native architectures, focusing on reliability, security, and performance. I thrive in fast-paced environments and love mentoring teammates to grow their skills and share knowledge across distributed teams.

Available to hire

I’m a seasoned Full Stack Engineer with 7+ years of experience building scalable web applications. I design intuitive front-end experiences using React and JavaScript, and I build robust back-end services with Python and microservices. I enjoy collaborating with remote teams, applying Kanban and Agile practices to deliver value incrementally.

I’m passionate about AdTech and cloud-native architectures, focusing on reliability, security, and performance. I thrive in fast-paced environments and love mentoring teammates to grow their skills and share knowledge across distributed teams.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Intermediate

Language

English

Fluent

Turkish

Advanced

Work Experience

Software Engineer at Trustate

January 1, 2023 - January 1, 2025

Led modernization of a legacy estate management system by migrating to a scalable architecture with NestJS, PostgreSQL, and GraphQL; refactored core backend into modular, domain-driven structures aligned with Clean Architecture using monorepos (Nx). Built automated workflows for estate handling with event-driven architecture using AWS SQS, Lambda, and Trigger.dev; designed resilient task pipelines with retries and deduplication; developed internal tools with Retool; enhanced observability with CloudWatch and custom dashboards; provisioned infrastructure with Terraform and managed serverless deployments across AWS; strengthened authentication with OAuth2 and JWT; conducted code reviews and mentored teams on backend and cloud patterns; contributed to DevOps best practices. Initiated cross-functional collaboration with product, design, and operations to deliver scalable backend solutions.

Software Developer at JN Tech Solutions Ltd

January 1, 2021 - January 1, 2023

Developed modular backend features using NestJS and integrated PostgreSQL with TypeORM; leveraged AWS Lambda for image transformation and PDF generation triggered via SQS/SNS; managed file uploads and secure access via AWS S3 with pre-signed URLs; implemented real-time features using NestJS Gateway via EC2-managed Docker containers; maintained CI/CD workflows with GitHub Actions and deployed to AWS ECS (Fargate) and Elastic Beanstalk; configured CloudFront and Route 53 for API gateway routing; set up health checks and log dashboards with CloudWatch; collaborated across product and DevOps to ensure security, scalability, and uptime for AWS-hosted services.

Junior Software Developer at Epigra

January 1, 2020 - January 1, 2021

Developed CRUD endpoints with Express.js and MySQL via Knex.js; implemented simple authentication with JWT; refactored routes into services and middleware for modularity; assisted with Docker-based local development; participated in daily standups, code reviews, and pair programming to grow engineering skills.

Senior Full Stack Engineer at Trustate

February 1, 2024 - March 1, 2026

Designed and implemented scalable front-end web applications using React and modern JavaScript, enhancing user experience and performance in healthcare portals. Led back-end development leveraging Python and microservices to create secure REST APIs for claims processing, improving data retrieval speeds by over 30%. Collaborated with cross-functional, remote teams using Kanban to deliver iterative improvements aligned with business objectives. Defined scalable cloud architecture with AWS for high availability and fault tolerance; established rigorous QA processes including unit, integration, and end-to-end testing with Jest. Optimized cloud resources with serverless components (AWS Lambda) to reduce costs and increase scalability. Mentored junior developers, and refactored legacy Angular components to React, achieving 25% faster load times and improved accessibility.

Full Stack Developer at BitStake

September 1, 2021 - December 1, 2023

Developed dynamic React applications with Redux for data visualization dashboards in marketplace environments. Implemented back-end services using Python and Node.js, integrating with AWS services (S3, EC2, RDS) to support scalable microservices. Led cloud infrastructure management and CI/CD pipelines, improving deployment frequency and reducing downtime. Worked in a fully remote Kanban-driven team to deliver features rapidly while maintaining high code quality. Contributed to architecture decisions focusing on scalability, security, and performance. Integrated third-party APIs and internal services for seamless data flow; conducted code reviews and enforced best practices in JavaScript, React, and Python. Implemented OAuth2 and JWT authentication to safeguard user data. Facilitated cross-team communication and English-language documentation to align stakeholders.

Software Engineer Intern at Epigra

March 1, 2020 - September 1, 2021

Contributed to front-end development with React, delivering production-ready components and improving responsiveness. Supported back-end API development using Node.js and Python, enabling full-stack feature delivery and integration with cloud services. Participated in agile ceremonies, practiced Git workflows and code reviews, and assisted in migrating legacy UI components to modern React frameworks. Implemented unit and integration tests with Jest to ensure robustness. Collaborated with remote teams and stakeholders, communicating technical concepts in English to drive project progress.