Javascript Developer

Senior Node.js Engineer | Open Theory Labs

Open Theory Labs is looking for a Senior Node.js Engineer to build and scale the backend behind high-performance trading platforms across web and mobile. This is a high-ownership role. You'll shape the architecture, own critical systems, and make sure the platform stays fast, secure, and reliable at scale.

What you'll own

• Backend architecture: design and build scalable, maintainable services in Node.js (TypeScript) that power web and mobile apps.
• Real-time systems: build low-latency features with WebSockets and event-driven architecture, including live prices, account updates, and notifications.
• APIs and integrations: design clean REST and GraphQL APIs and integrate with trading systems, payment gateways, KYC providers, and third-party services.
• Performance and scale: optimise for high throughput and low latency, with caching, queues, and efficient data access patterns.
• Security and reliability: build with security first, including authentication, authorisation, encryption, audit trails, and protection of sensitive financial data.
• Data and analytics: structure data and events so product and growth teams have the insights they need.
• Engineering excellence: set standards for code quality, testing, CI/CD, and observability, and mentor other engineers.

What we're looking for

• 5+ years of backend development experience, with deep expertise in Node.js and TypeScript.
• Experience building trading, fintech, or other high-stakes financial systems.
• Strong knowledge of real-time technologies such as WebSockets, Socket.IO, or event streaming.
• Solid experience with databases like PostgreSQL, MongoDB, and Redis.
• Experience with message queues such as Kafka, PubSub, or BullMQ.
• Hands-on experience with cloud infrastructure (AWS and GCP), Docker, and CI/CD pipelines.
• A strong understanding of security best practices for financial applications.

Why this role

• You'll own critical systems on a product with real users and real impact.
• You'll make architecture decisions, not just implement tickets.
• You'll work with a team that values clean code, clear thinking, and well-built products.

📍 Gurugram