Full Stack Engineer

Job Summary

• Tongston is seeking a Full Stack Engineer (Back-End Focus) to help build and scale T-World and the product backend for T-Cell as a standalone AI product.
• T-Cell may serve T-World and approved external applications or institutions through defined interfaces.
• This role covers T-Cell, T-World and other current and future Tongston products, services and approved integrations, as assigned within its remit.
• This role is ideal for a backend-leaning engineer who can own APIs, data models, integrations, reliability, and application connections to AI services—while remaining comfortable delivering lightweight React web UI when needed to support product flows and internal tools.
• You will Participate in Agile ceremonies: planning, execution, review, and iteration.

Roles and Responsibilities

Back-End & Architecture (Primary):

• Build and maintain server-side services and APIs using Node.js and Express
• Design, implement, and optimize MongoDB schemas, indexes, and query patterns
• Own backend integrations including:
• Authentication (Firebase)
• Media storage (Cloudinary, AWS S3)
• Environment configuration and secrets management
• Logging and monitoring
• Define modular product service boundaries for T-World and standalone T-Cell. Keep T-Cell’s accounts, organisation configuration, access controls and application APIs independent of T-World-specific widgets or database structures, while reusing appropriate shared Technology services.
• Ensure backend reliability, performance, and scalability
• Implement T-Cell product APIs, authorised client integrations, user/organisation isolation, configuration and usage records as required by approved scope. Define contracts for context, permitted actions, structured outputs and errors with AI Engineering.
• Implement deterministic product validations, calculations and workflow rules in application services. Enforce permissions and validate all requested writes or actions even when they originate from an AI agent.

Front-End Support (Secondary):

• Ship or support React components required to validate backend APIs, AI flows, or admin/internal tooling
• Collaborate with frontend engineers to ensure clean API contracts and smooth UI ↔ backend interactions
• Maintain code quality via pull requests, documentation, and shared standards

AI Enablement:

• Integrate Technology-owned interfaces and application APIs with the T-Cell AI services supplied by AI Engineering, including connections to T-World and approved external systems.
• Support AI-powered experiences such as:
• Assistants
• Search
• Content generation
• Ensure safe and reliable AI integrations, including:
• Error handling and fallbacks
• Latency and timeout management
• Rate limiting and caching
• Storage, access controls and release support for versioned prompts and configurations; Data owns prompt creation and optimisation, and AI Engineering owns runtime prompt assembly
• Traceable outputs for debugging and evaluation
• Provide shared observability, controlled test environments and traceable API responses for Data’s evaluation and Education’s output review. Own interface/API, access-control, data-isolation and application reliability tests; AI Engineering owns agent, retrieval and model execution tests.

Delivery, Security & Operations:

• Support CI/CD pipelines using GitHub Actions
• Follow secure practices for:
• Secrets and key management
• Access control and offboarding hygiene
• Build and maintain the application deployment, monitoring and operational arrangements for T-World and standalone T-Cell, coordinating infrastructure work with the Technology team and deploying AI packages supplied by AI Engineering.

Knowledge, Skills & Attitude Requirements

Technical Knowledge & Skills:

• Strong experience with Node.js and backend design patterns
• Strong experience with MongoDB (schema design, indexing, aggregation, performance tuning)
• Solid working knowledge of Express.js
• Comfort working with React for integration-level UI tasks
• Familiarity with REST APIs, server-side architecture, and environment configuration

Soft Skills & Attitude:

• Strong analytical and problem-solving skills
• Clear communication and collaboration across teams
• Ability to prioritize, execute, and deliver with attention to detail
• Ownership mindset and comfort working in a fast-paced environment
• Strong alignment with Tongston’s mission, values, and culture. Learn more about Tongston’s culture: https://tongston.com/about

Nice-to-Have Knowledge & Skills:

• Exposure to AI integrations (LangChain or similar)
• Familiarity with Web3 integration workflows (wallets, signing, token flows)
• Experience with background jobs, queues, or serverless patterns
• Exposure to cloud infrastructure (AWS)

Core Stack

Back-End (Primary Focus)

• Node.js with Express (API services / serverless routes where applicable)
• MongoDB (Atlas & Compass)

Front-End (Supportive)

• React (Web)
• Vite
• Tailwind CSS
• State & data: TanStack Query, Zustand

Platform & Infrastructure

• Authentication: Firebase (synced with MongoDB)
• Storage:
• Cloudinary (short-term media handling)
• AWS S3 (long-term storage with immediate migration )
• CI/CD: GitHub Actions
• Security: CodeQL, Dependabot, basic OWASP-aligned practices

Service Integration Knowledge

• Working awareness of AI orchestration frameworks and service contracts; AI Engineering owns the agent runtime and orchestration implementation
• Integration with approved AI service APIs; Data owns prompt content and AI Engineering owns model execution

Web3 (Exposure-Level)

• Wallets, signing flows, token interactions-conversion
• On-chain vs off-chain boundaries (Deep smart contract development is not required)