Full Stack Developer (Flutter & Backend)

About Klass Online

Klass Online is building a powerful marketplace for knowledge, skills, and expertise, connecting people with the individuals who can help them move further, faster.

Our vision is to transform the way knowledge is discovered, shared, and valued. We believe expertise should never be limited by geography or outdated models. Klass Online is creating a platform where talent can reach a wider audience, knowledge can create real opportunity, and people can access the right expertise when it matters most.

We are building with scale, ambition, and long-term impact in mind. Klass Online is driven by people who take ownership, challenge conventional thinking, and want their work to have a visible impact on the company they are helping to build.

We are not here to follow an existing model. We are building the one that comes next.

Learn more & download our app: https://www.klass.online/

https://apps.apple.com/qa/app/klassonline/id6751298173

https://play.google.com/store/apps/details?id=com.klass.online&hl=en_US

Role Overview

The ideal candidate will have solid experience in backend development while also being comfortable working with Flutter applications. You will be responsible for developing secure, scalable, and high-performance solutions, integrating APIs, and supporting both mobile and web applications.

Key Responsibilities

• Develop and maintain scalable backend services and RESTful APIs.

• Develop and maintain Flutter mobile and web applications.

• Integrate third-party APIs and external services. Optimize application performance, security, and database efficiency.

• Troubleshoot, debug, and resolve technical issues.

• Collaborate with designers, product owners, and the development team.

• Participate in testing, deployment, and production releases Requirements

• Minimum 5 - 6 years of experience as a Full Stack Developer.

• Strong experience with Flutter (Dart) for mobile and/or web development.

• Strong backend development experience with API design and integration.

• Experience with SQL/NoSQL databases. Experience with cloud platforms (Azure is an advantage). Knowledge of authentication, security, and performance optimization.

• Experience with Git and Agile development practices. Strong analytical and problem-solving skills.

Nice to Have

• Experience with Azure services.

• Experience in EdTech or SaaS platforms.

• Experience with AI/LLM integrations.

• Knowledge of CI/CD pipelines and DevOps practices.

Application Question(s):

• How do you structure state management, dependency injection, and clean architecture in a complex Flutter app to ensure optimal UI rendering performance across both mobile and web builds?

• How do you design a high-throughput backend API service to handle dynamic database reads/writes during peak traffic spikes without compromising transaction integrity or DB latency?

• Detail your security approach for integrating third-party payment gateways and backend webhooks, specifically addressing idempotency, payload verification, dynamic authentication tokens, and mitigating replay attacks.

• Describe a complex SQL query optimization or NoSQL database sharding/indexing strategy you designed to drastically reduce execution time on dynamic data operations

• How do you configure CI/CD pipelines, container orchestration, zero-downtime deployment strategies, and monitoring/alerting on cloud platforms (e.g., Azure)?

• If required to integrate AI/LLM functionality into a platform, how would you design the backend queue system, handle API latency asynchronously, manage prompt security, and stream real-time responses to the Flutter UI?

Education:

• Bachelor's (Required)

Experience:

• full-stack development: 6 years (Required)

• proven experience building apps with Flutter & Dart: 6 years (Required)

• hands-on cloud experience with Azure, AWS, or GCP: 6 years (Required)

Work Location: Hybrid remote in Doha (Doha)