Senior Integration Engineer

Senior Integration Engineer

Location: Remote
Type: Full-time

About Fastn

Fastn is on a mission to revolutionize how SaaS companies connect with their customers' environments. Powered by AI, we provide an embedded integration infrastructure that enables SaaS businesses to build, scale, and manage their integration ecosystem effortlessly.

With Fastn, companies can launch strategic integrations, create their own app marketplace, and unlock new revenue streams by offering seamless connectivity with the tools their customers already use. But our platform is more than just integrationsits about accelerating market penetration, driving partner-sourced revenue, and delivering smarter, more valuable customer experiences.

If youre passionate about leading integration strategies, scaling API connectivity, and mentoring teams in a high-growth SaaS environment, Fastn is the place to be.

What Youll Do

As a Senior / Lead Integration Engineer, you will play a critical role in architecting, building, and optimizing integrations between Fastn and a broad ecosystem of SaaS applications. You will lead integration initiatives, mentor engineers, and work closely with product and engineering leadership to drive seamless, scalable, and high-performance integrations.

Your Responsibilities

• Technical Leadership: Lead the architecture, design, and development of integrations, ensuring they are scalable, high-performance, and secure.
• API Engineering: Design and implement robust RESTful, GraphQL, and Webhook-based APIs to enable seamless data flow.
• Scalability & Performance: Architect integrations to handle millions of transactions per second/minute with sub-millisecond response times.
• Automation & AI-Driven Integrations: Utilize AI/ML-based automation and data mapping to enhance connectivity and reduce manual effort.
• Security & Compliance: Implement best practices for OAuth, API authentication, data privacy, and regulatory compliance (SOC 2, GDPR, etc.).
• Collaboration: Partner with engineering, product, and customer success teams to ensure integrations align with business and technical goals.
• Mentorship & Team Growth: Mentor junior engineers, conduct code reviews, and provide technical guidance to elevate the overall integration team.
• Monitoring & Reliability: Establish observability, error handling, and performance monitoring to ensure integration reliability.

What Were Looking For

Were seeking a highly skilled engineer and leader who thrives in building scalable integration solutions and mentoring teams in a fast-paced SaaS environment. If you enjoy working with APIs, automation, and large-scale systems, this role is for you.

Must-Have Skills & Experience

• 5+ years of experience in integration engineering, API development, or automation.
• Proven track record in leading and architecting scalable API integrations.
• Strong expertise in RESTful APIs, GraphQL, Webhooks, and event-driven architectures.
• Experience designing integrations that handle millions of transactions per second/minute with low latency.
• Proficiency in backend programming languages (Java, Python, or Node.js).
• Hands-on experience with cloud platforms (AWS, GCP, or Azure) and serverless architectures.
• Strong knowledge of API security, authentication (OAuth, JWT, OpenID), and compliance (SOC 2, GDPR, etc.).
• Experience working with message queues (Kafka, RabbitMQ, etc.) and event-driven architectures.
• Previous experience leading or mentoring engineers in a high-growth startup or SaaS company.

Nice-to-Have Skills

• Experience with iPaaS platforms like Mulesoft, Workato, or Tray.io.

• Familiarity with AI/ML-driven automation in integrations.

• Hands-on experience with developer tooling, B2B SaaS integrations, or API marketplaces.

Why Join Fastn?

• Shape the