Senior Backend Engineer 🥇 | Knock | Remote

Introductory paragraph

At Knock we’re building a developer first notifications-as-a-service platform so that product teams don’t need to build in-house notification engines. We wrap all of the cross-channel notifications complexity into an API call and provide a dashboard for the non-technical members of the team to design, launch, and iterate on notification flows and content.

About us

My name: Chris Bell

My position: CTO / Co-founder

Company name: Knock


Company info and history:

  • We’re a small team of engineers and product thinkers on a mission to improve on how software communicates with its users.
  • We’re headquartered in New York City, but we are a fully distributed team.
  • We were founded in January 2021 and raised our initial round of Seed funding in March 2021.
  • We’re backed by folks like Adam Gross (fmr CEO @ Heroku), Guillermo Rauch (CEO @ Vercel), Michael Grinich (CEO @ WorkOS), and Scott Belsky (CPO @ Adobe)
  • We’re all in on Elixir, using it throughout our services. And more importantly, we’re all in on supporting the community (I help organize @ EMPEX conf and co-host @ Elixir Talk).

About the job

Job title: Senior Backend Engineer :1st_place_medal:

Job description:
We’re looking for a founding backend engineer to come and join the team. That means coming in and playing a meaningful part in shaping the direction of the company, product, and culture, as well as making lots of large technical decisions along the way.

We have a lot of technically challenging and rewarding problems to solve along the way as we build Knock into a robust and scalable platform for powering product notifications, and you’ll be at the pointy end of those problems as our founding backend engineer.

Salary range: $160 - 190k + sizable equity grant

Position on remote work: Remote encouraged but within US timezones only (GMT-10 to GMT-5). We also have hub offices in Boulder, CO and NYC and are actively practicing a “hybrid” model, should you wish to spend time in an office.

Qualifications or experience required:

  • You have 5+ years experience working on backend services in a language such as Scala, Ruby, Python, Go, Node.JS, Erlang, or Elixir (some prior Elixir experience is advantageous but not a hard requirement).
  • You have a track record of designing, building, and operating services in production at some meaningful measure of scale.
  • You have knowledge of message brokers or queues in SQS, Kafka, RabbitMQ or similar.
  • You’ve worked with AWS, Terraform, k8s or similar tools in the past.
  • You’re excited about the opportunity to be at the “ground-floor” of an early stage startup and help build the team, processes, and product in order for it to succeed.

What the successful job applicant will be working on:

  • Working exclusively on our Elixir based notification delivery engine, whereby we execute customer workflows and deliver notifications to end users, at scale.
  • Architecting and building our infrastructure and services for the next generation of scale and resilience.
  • Designing and building customer facing APIs
  • Contributing to and maintaining our open source SDKs in a variety of different languages
  • Working alongside the CTO in making large, long-lasting technical decisions.

About the interview process

  • Screening call w/ hiring manager (30 - 45 mins). We’ll discuss your work experience and background and go into more depth about your past projects. We’ll also discuss the role at Knock and our mission.
  • Pair programming exercise (45 mins) - we work on a shared problem together whereby we’ll implement a service that reads jobs from a JSON file, processes them, and delivers them to downstream HTTP services. You’ll be “driving” the pair over a Zoom call and can complete the exercise in whatever language you feel most comfortable in.
  • Systems design exercise (30 mins) - we discuss how we might turn the above into a “real service” in production, and walk through a classic systems design problem using whiteboarding software.
  • Interview w/ CEO (1 hour) - you’ll get an opportunity to meet the CEO and co-founder of Knock and ask additional questions you may have about the mission and business model.
  • Offer - we’ll discuss the terms of an offer for a role at Knock, and walk you through our benefits.

Further info

Learn more:

If you’re interested you can speak to me directly at or on the Elixir slack @cjbell. I’m happy to spend time telling you more about what we’re doing and answering any questions you might have before you apply. Otherwise, please send your resume to