Principal Engineer

Principal Engineer

Location :

Remote / Islamabad 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 integrations its about accelerating market penetration, driving partner-sourced revenue, and delivering smarter, more valuable customer experiences. If youre passionate about

architecting large-scale distributed systems, leading high-impact engineering teams, and pushing the boundaries of SaaS connectivity , Fastn is the place to be. What Youll Do

As a

Principal Engineer , you will play a

foundational role

in defining and executing Fastns technical vision. You will be responsible for

architecting, optimizing, and scaling

our

AI-powered

integration infrastructure to handle

millions of transactions per second

with

sub-millisecond latency . Youll work closely with engineering leaders, product teams, and executives to drive

technical strategy, innovation, and engineering excellence . This role is ideal for someone who is not just a world-class engineer but also a

strategic thinker, mentor, and influencer

who thrives in a fast-moving, high-growth startup environment. Your Responsibilities

Technical Strategy & Architecture :

Define and lead the

architecture, scalability, and reliability

roadmap for Fastns core platform. High-Scale Systems :

Design and optimize

low-latency, high-throughput distributed systems

capable of handling

millions of transactions per second / minute . AI-Powered Integrations :

Leverage

AI / ML

to enhance automation, data mapping, and intelligent API connectivity. Performance Optimization :

Drive initiatives to ensure sub-millisecond API response times and seamless scaling. Security & Compliance :

Implement world-class

security best practices

across API authentication, data privacy, and regulatory compliance (SOC 2, GDPR, etc.). Technical Leadership & Mentorship :

Lead and mentor engineers , fostering a culture of technical excellence, knowledge-sharing, and continuous improvement. Cross-Functional Collaboration :

Partner with product, engineering, and customer success teams to align business goals with technical execution. Hands-On Engineering :

While youll shape the big-picture strategy, you should also be comfortable writing high-impact code and conducting deep technical reviews. What Were Looking For

Were seeking an

exceptional technical leader

who thrives in solving

high-scale distributed systems challenges

while also guiding and mentoring top-tier engineers. If youre

obsessed with performance, scalability, and building world-class engineering teams , this role is for you. Must-Have Skills & Experience

10+ years of hands-on software engineering experience , with at least

3+ years in a Principal / Architect role

in high-scale SaaS, API, or distributed systems. Proven track record of

designing, building, and scaling distributed systems

handling

millions of transactions per second / minute

with

sub-millisecond latency . Deep expertise in

backend development

using

Java, Python, or Node.js

(Fastns stack is flexible). Strong understanding of

high-performance, low-latency computing , caching strategies, and database optimization. Experience working with

cloud platforms (AWS, GCP, Azure)

and

serverless architectures . Knowledge of

event-driven architectures ,

message queues (Kafka, RabbitMQ, etc.) , and

real-time data processing pipelines . Expertise in

API security, authentication (OAuth, JWT, OpenID), and compliance standards (SOC 2, GDPR, etc.) . Experience in

leading and mentoring engineering teams , fostering a high-performance, collaborative culture. Nice-to-Have Skills

Experience with

iPaaS (Integration Platform as a Service)

tools like Mulesoft, Workato, or Tray.io. Hands-on experience with

AI / ML-driven automation

in integrations and API intelligence. Previous work in

developer tooling, B2B SaaS integrations, or API marketplaces . Why Join Fastn?

Shape the Future of SaaS Connectivity

Build and lead a game-changing integration infrastructure.

Work on Cutting-Edge AI & API Technologies

Be at the forefront of AI-powered SaaS integrations. High-Impact, High-Growth Environment

Your contributions will directly define Fastns trajectory. Strong Engineering Culture

Collaborate with world-class engineers solving highly complex challenges. Competitive Compensation

Market-leading salary, meaningful equity, and a flexible work environment. Join Us in Building the Future of SaaS Connectivity!

If youre excited to

architect high-scale distributed systems, lead engineering teams, and push the boundaries of performance and scalability , wed love to hear from you. Apply now and help shape the future of SaaS integrations!

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