fastn, Inc.

Principal Engineer

Pakistan full-time Senior Salary not listed
full-time Senior level Technology & IT Curated
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About the role

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!
Originally posted on Himalayas

Interview prep

Walk in with sharper answers.

Use this as a quick practice sheet before you speak with the employer.

Senior
Technology & IT API integration Javascript MySQL Python Remote Collaboration Senior level

Likely questions

  1. Tell us about work you have done that is close to the Principal Engineer role.
  2. How would you approach your first 30 days at fastn, Inc.?
  3. Which of API integration, Javascript and MySQL have you used recently, and what did it help you achieve?
  4. How have you led people, improved a process, or made a hard decision in a previous role?
  5. How do you handle busy days, changing priorities, or pressure at work?

Prepare before the call

  • A recent example that proves your experience with API integration, Javascript and MySQL.
  • One short story with a problem, your action, and the result.
  • Two examples that show the strengths listed on your CV.
  • A clear reason why this role and company interest you.
  • Your availability, preferred work style, and salary expectations.

Ask them

  • What would success look like in the first 90 days?
  • What are the main problems this hire should help solve?
  • How does the team give feedback and measure good work?
  • What does a normal working week look like for this role?
Practice line

I am interested in the Principal Engineer role because I can bring practical experience in API integration, Javascript and MySQL, learn the team quickly, and contribute to the outcomes fastn, Inc. needs from this hire.

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