Backend Engineer - Intents API

Your core mission will be to lead the technical direction and implementation of the central off-chain coordination system for our next-generation architecture. This is a critical infrastructure role focused on security, performance, and reliability.

• System Architecture & Development: Design, implement, and maintain the highly available, low-latency APIs required for seamless application interaction, quote management, and system-wide status retrieval using Node.js/TypeScript and the NestJS framework.
• Security & Validation Logic: Develop advanced and rigorous validation mechanisms to ensure data integrity and prevent fraudulent activity within the system, including logic for checking digital signatures, timing constraints, and necessary co-signatures.
• Real-Time Data Distribution: Build and optimize the infrastructure for immediate, real-time broadcasting of critical, validated data to all participating external liquidity providers and execution partners.
• Multi-Phase Status Tracking: Integrate with specialized data indexing services to reliably monitor and track the multi-phase lifecycle of core system objects across distributed environments, ensuring users and applications receive accurate, real-time status updates.
• Optimization of Execution Coordination: Implement advanced logic for data aggregation, caching, and mechanisms for partner reputation and selection to ensure the best possible user experience.
• Security & System Integrity: Proactively identify and resolve potential security vulnerabilities in the off-chain coordination flow to maintain the trustless nature of the overall system.
• Cross-Functional Collaboration: Work closely with the core Smart Contract and Product teams, and ensure comprehensive documentation for the backend architecture and APIs., + Embrace your own differences

• Respect and welcome the unique qualities of others
• See others' differences as an opportunity to grow

• Own it, do it

• Own tasks end-to-end
• Hold yourself to a high bar for execution
• Make bold decisions, and be accountable
• Understand your limitations and seek for help

• Fail forward

• Try - don't be afraid to fail
• Learn - don't make the same mistake twice
• Adapt - grow with the experience

• Have fun together

• Take the time to get to know and understand each other better
• Don't take yourself too seriously and keep it light-hearted
• Fun should be coming from a place of love and respect, * Annual team offsites (Thailand in 2023 and Vietnam in 2024 were a blast, Marrakech in March 2025 was blast-ier; let's see what happens in 2026!)

• 30 days of PTO
• Flexible remote days
• Flexible working hours
• Equity participation from day 1
• Entitlement to work computer (choice of equipment)
• An annual 1,000€ personal development budget once you have worked 6+ months (pro-rated the first year)
• A one-time 1,000€ remote budget to use on coworking, office setup, etc.

If you join us as an independent contractor, you're only entitled to the first five benefits of this list.

• 5+ years of backend development experience building and scaling high-throughput, mission-critical services.
• Expert proficiency in TypeScript/Node.js, with deep working experience using the NestJS framework for building scalable backend applications.
• Deep understanding of blockchain data and security primitives, including EIP-712 signatures, transaction execution flows, and reading on-chain events/logs.
• Proven experience in designing and scaling real-time communication systems (e.g., WebSockets, Redis Pub/Sub patterns).
• Solid experience with relational databases (PostgreSQL, etc.) and optimizing complex queries.
• Strong system design skills, with the ability to build fault-tolerant and highly available microservices.
• Experience with monitoring, logging, and observability tools to maintain system health.
• Ability to work autonomously, prioritize tasks effectively, and drive complex projects to completion in a fast-paced environment.

Nice to haves

• Experience integrating with or developing against blockchain indexing services (e.g., Goldsky, The Graph, Subgraphs).
• Familiarity with Intent-centric architectures, Solvers, or off-chain order matching systems.
• Direct experience with cross-chain message passing or oracle systems like Polymer/Wormhole.
• Experience with Infrastructure as Code (e.g., Terraform) and cloud-native deployments (Kubernetes, AWS/GCP).

LI.FI is simplifying multi-chain DeFi for traditional financial institutions, fintechs and service providers by offering a unified API to access all on-chain liquidity across major blockchains for best price same-chain and cross-chain swaps. We are a passionate team on a mission to enable a fairer, more decentralised world. Apart from the tech, we care a lot about user experience and aim to make complex technologies accessible to everyone.