Integrations Engineer (Senior)

Apex Research is seeking an experienced backend engineer to join their team in Islamabad on a full-time, on-site basis. The successful candidate will play a critical role in developing and maintaining integration connectors for various legal practice-management systems and CRM platforms. This position requires a strong background in Node.js and backend engineering, with a focus on building robust, secure, and scalable integrations that support US personal injury law firms through Apex’s SaaS platform. The role involves end-to-end ownership of connector frameworks, including development, documentation, monitoring, and support.

Key Responsibilities
- Develop and maintain connector adapters for practice-management systems such as Litify, Clio, CasePeer, MyCase, Smokeball, along with existing adapters for Filevine and Neostella.
- Implement OAuth 2.0 authentication flows, including client-credential grants, token refresh mechanisms, encrypted credential storage, and webhook signature verification to ensure secure integrations.
- Build and enhance email integrations using Google Workspace or Microsoft 365 OAuth, supporting features like incremental inbox synchronization, threading, attachments, sending, replying, and matching emails to clients and cases with a review queue.
- Develop synchronization processes for HubSpot and ActiveTrack platforms.
- Design and maintain reliable job processing on a Postgres-backed queue system, handling retries, rate limiting, deduplication, idempotency, and dead-letter recovery to ensure data integrity and operational resilience.
- Maintain canonical data models and manage field mappings across multiple external systems to ensure consistent data exchange.
- Collaborate with the MCP engineer to support tool development against the partner API and keep OpenAPI documentation up to date.
- Monitor the health of integrations and provide onboarding support to law firms adopting these systems.

Required Qualifications
- Minimum of 5 years of experience in backend or integration engineering, with at least 3 years focused on Node.js development.
- Proficient in OAuth 2.0 protocols, webhook implementation with signature verification, handling pagination, rate limits, and retries when working with third-party APIs.
- Strong experience with PostgreSQL and asynchronous queue-based job processing.
- Commitment to writing automated tests as part of the development process to ensure code quality and reliability.

Preferred Qualifications
- Familiarity with Gmail API or Microsoft Graph for email integration.
- Experience working with legal practice-management APIs such as Filevine, Litify, or Clio.
- Knowledge of HubSpot API integration.

Apex Research offers the opportunity to work on a cutting-edge SaaS platform that supports critical legal research and due diligence services. The role provides a chance to contribute to a technology stack built on AWS, Node.js, and Next.js, with a focus on AI-driven services and automated reporting. This position is ideal for candidates who thrive in a collaborative environment and are passionate about building secure, scalable integrations that directly impact the efficiency of US personal injury law firms.