developer-apis enterprise-software telephony
San Francisco, CA

Principal Software Engineer- Phone Numbers


Because you belong at Twilio

The Who, What, Where and Why


Twilio is looking for a Principal Software Engineer who is excited about solving some of the hardest problems at Twilio, enabling our high volume customers to grow and expand globally by onboarding them quickly and seamlessly.

  • You like to think at scale and design, develop and operate production microservices that meet goals of low latency, high availability, resiliency and quality in a cloud environment.
  • You bring experience with complex distributed systems, working across stack both in backend systems, REST API’s and frontend systems (some of the technologies we use are Java, Scala, Python, ReactJS, Node, PHP, MySQL).
  • You have expertise in complex data modeling, have experience in data pipelines, such as Kafka, and are comfortable with managing large database clusters, such as MySQL.

Bachelor’s degree and 8+ years of software engineering experience required.


  • A great day for you would be working alongside a collaborative team, white-boarding ideas, building APIs and UIs used by all Twilio customers, as well as constantly improving services that power Twilio’s top products and also generate significant revenue.
  • We are working on enabling millions of developers to use Twilio across the world and help companies expand their business globally.
  • You will be helping more junior developers by mentoring them, providing guidance, and positively influencing their careers.


The Phone Number Services team works on solutions to onboard high-volume customers and bring their business to Twilio. Some of the services we provide include transparent and automated phone number porting, hosted SMS and provisioning shortcodes. We also work on solutions to ensure we always have up-to-date inventory and can satisfy customers’ demand for different types of phone numbers across the world.

Twilio is empowering the world’s developers with modern communication in order to build better applications.

Twilio is truly unique; we are a company committed to your growth, your learning, your development and your entire employee experience. We only win when our employees succeed and we're dedicated to helping you develop your strengths. We actively promote innovation through experimentation across the company by having frequent hackathons throughout the year. We have a cultural foundation built on diversity, inclusion and innovation and we want you and your ideas to thrive at Twilio. Come join us.  


This position will be located in our beautiful office at 375 Beale Street in San Francisco. You will enjoy our incredible perks: catered meals, snacks, game room, ergonomic desks, massages, education / health credits, Wednesday Night dinners, bi-weekly All Hands and more. What you will also get to experience is a company that believes in small teams for maximum impact; that strives to balance work and home life, that understands that this is a marathon, not a sprint; that continuously and purposefully builds an inclusive culture where everyone is able to do and be the best version of themselves. We seek people who naturally demonstrate our values, who are challenged by problems, empower others to thrive, people who can draw the owl and not be beholden to one playbook.

About us:

More than 2 million developers around the world have used Twilio to unlock the magic of communications to improve any human experience. Twilio has democratized communications channels like voice, text, chat, and video by virtualizing the world’s telecommunications infrastructure through APIs that are simple enough for any developer to use, yet robust enough to power the world’s most demanding applications. By making communications a part of every software developer's toolkit, Twilio is enabling innovators across every industry — from emerging leaders to the world’s largest organizations — to reinvent how companies engage with their customers. Founded in 2008, Twilio has over 1,400 employees, with headquarters in San Francisco and other offices in Bogotá, Dublin, Hong Kong, London, Madrid, Mountain View, Munich, New York City, Atlanta, Singapore and Tallinn.

Twilio is proud to be an equal opportunity workplace and is an affirmative action employer. We are committed to equal opportunity regardless of race, color, ancestry, religion, gender, gender identity, parental or pregnancy status, national origin, sexual orientation, age, citizenship, marital status, disability, or Veteran status and operate in compliance with the San Francisco Fair Chance Ordinance.

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