Case Study: HackerRank achieves reliable, scalable real‑time video coding interviews with Twilio Video

Hackerrank Personalizes Coding Interviews with Video and Real-Time Collaboration

HackerRank, a platform for developer recruiting and live technical interviews, needed to combine instant code validation across 30 languages with the ability to hear candidates’ thought processes during live coding sessions. Their initial off‑the‑shelf video provider failed at scale—especially for enterprise customers behind strict firewalls—forcing interviewers out of the product and breaking the real‑time collaborative experience.

HackerRank integrated Twilio Programmable Video (after a two‑week proof of concept and about a month of work), using Twilio’s TURN servers and TCP/443 tunneling to reliably traverse restrictive networks. The result was a seamless, in‑app video + coding experience with far fewer disconnections, faster feature delivery via a simple API, and the ability to scale globally while preserving real‑time collaboration and candidate evaluation.

HackerRank

Harishankaran Karunanidhi

Co-Founder & CTO