Senior API Integration Consultant

Quick Facts

• Role: Senior API Integration Consultant

• Work model: Technical consulting (B2B)

• Mode: Remote

Description

You will support a SaaS/reservation marketplace client with advanced API integration for real-time, two-way synchronization of calendars and bookings, with minimal delay. The goal is to stabilize the solution and eliminate the risk of double booking through robust event-driven design, webhook handling, and reliability mechanisms.

Responsibilities

• Provide technical consulting and architecture guidance for integrating external REST APIs using JSON and OAuth 2.0

• Analyze and design two-way synchronization logic, including asynchronous mechanisms and conflict prevention (race conditions, double booking)

• Advise on implementing, validating, and handling webhooks; design event-driven architecture

• Debug and diagnose API interactions (request/response), identify integration errors, and resolve data consistency issues

• Design reliability mechanisms (retry), idempotency, logging, and monitoring

• Support the development team during testing and production rollout (optionally implement minor code fixes)

Requirements

• Several years of experience in Backend Development or system integrations at a Senior level

• Very good practical knowledge of REST API, JSON, and OAuth 2.0

• Experience with webhooks and event-driven architecture

• Documented experience in designing and implementing two-way integrations and resolving data consistency problems

• Strong knowledge of reliability patterns: queueing, retry logic, idempotency, deduplication, and error handling

• Ability to independently lead technical consultations, precisely diagnose problems, and propose mature architectural solutions

Benefits

• B2B Time & Material contract (pay for actual hours or an agreed monthly package)

• Part-time flexibility based on current demand

• Work scheduled around agreed consultation times with priority technical requests (higher engagement during key testing and rollout moments)

• Real impact: domain expert whose decisions directly affect integration stability.