Senior Software Engineer, Traffic

About the Team

Traffic Engineers enable fast and reliable delivery of Slack to our 12M+ (and growing fast!) globally distributed daily active users. We are responsible for traffic management both at the Edge and within our cloud infrastructure, working to drive up reliability and drive down latency. We partner closely with SRE and application developers, enabling them to focus on implementing business logic instead of worrying about how to get traffic in and out of their services.

Slack already has a mature and stable infrastructure but we are taking everything to the next level by implementing even more intelligent components that utilize real-time performance metrics to make traffic routing decisions and further optimize our customer experience. Our team consists of hybrid systems, software, and network engineers who take ownership of large scale infrastructure while continuously improving reliability and building automation.  

In summary, ingress load-balancing of global Slack traffic.

Slack has a positive, diverse, and supportive culture — we look for people who are curious, inventive, and work to be a little better every single day. In our work together we aim to be smart, humble, hardworking and, above all, collaborative. If this sounds like a good fit for you, why not say hello?

About the Role

This is a full-time senior-level engineering position based in San Francisco.

What you will be doing

  • Design and build tools that will process performance data we collect from millions of our users around the world in order to compile a precise metric based map of the Internet as it relates to Slack
  • Design and build tools that will utilize this map to improve our DNS routing decisions in order to optimize Slack user experience and achieve even higher levels of availability and lower latency
  • Design and implement scalable and reliable traffic delivery infrastructure
  • Design, build, maintain and operate production systems that balance traffic across our edge regions and various backend services
  • Operate systems that protect our network from DDoS attacks
  • Automate operational traffic workflows, building automation and eliminating toil

What you should have

  • The ability to lead larger projects, from start to finish, where the scope is mostly understood, e.g. 5-8 years of work experience
  • Intense curiosity about how things work
  • You are able to analyze and optimize the performance of high-traffic Internet applications and can point to things you’ve worked on
  • Strong communication skills; the ability to explain complex technical concepts to designers, support, and other engineers is no problem for you
  • The experience/mindset to mentor and model of standard methodologies for unit tests, code review, design documentation, debugging, and troubleshooting
  • An expert understanding of TCP/IP, DNS, and network-related protocols
  • At scale experience with Linux / Unix operating on high volume systems
  • Coding experience in high-level languages such as C/C++, Go and Python
  • A significant level of experience with algorithms, data structures, complexity analysis, distributed systems and software development
  • Proven experience with configuring and operating traffic management components such as load balancers, web, DNS and proxy servers in production
  • A BS, MS, or Ph.D. in engineering or related technical field (or equivalent work experience)

Slack is a layer of the business technology stack that brings together people, data, and applications – a single place where people can effectively work together, find important information, and access hundreds of thousands of critical applications and services to do their best work. From global Fortune 100 companies to corner markets, businesses and teams of all kinds use Slack to bring the right people together with all the right information. Slack is headquartered in San Francisco, CA and has ten offices around the world. For more information on how Slack makes teams better connected, visit

Ensuring a diverse and inclusive workplace where we learn from each other is core to Slack’s values. We welcome people of different backgrounds, experiences, abilities and perspectives. We are an equal opportunity employer and a pleasant and supportive place to work.

Come do the best work of your life here at Slack.