Senior Software Engineer

About the team

The Infra team runs the core engines behind every HackerRank assessment. We own Coderunner, the service that compiles, executes, and scores all coding and database submissions – tens of millions of runs each month. Our LSP infrastructure drives the autocomplete and autosuggest features candidates rely on for speed and accuracy. We also deliver the unified IDE used across Screen, Interview, SkillUp, Engage, and Community, giving candidates a smooth space to show their best work. Looking ahead, we are building an AI-powered platform to help our content team ideate, generate, validate, and publish new challenges faster than ever.

About the role

As a Senior Full-Stack Engineer on the Infra team, you’ll work across all of our critical projects. Because our charter cuts horizontally through HackerRank, every feature, fix, or optimisation you release improves multiple product lines at once. You will design, build, and operate scalable systems on both the front end and the back end, owning each change from design and code through tests, metrics, and rollout. You’ll partner with product and design, mentor junior engineers, and deliver improvements that reach millions of developers in hours – not months.

What you will do

- Build and ship front-end features, then integrate them with back-end services.
- Boost the IDE’s speed, accessibility, and usability across Screen, Interview, SkillUp, Engage, and Community.
- Keep core platform services fast and reliable while processing tens of millions of submissions each month.
- Embed LLMs and other AI agents into both UI flows and public APIs.
- Write design docs, unit and integration tests, dashboards, and alerts for every change you own.
- Review code, mentor junior engineers, and share knowledge through pairing and short talks.
- Work with product and design to turn rough ideas into scoped, testable stories.
- Join the on-call rotation, resolve production issues end-to-end, and leave the system stronger after each incident.

You will thrive in this role if you

- Own the whole flow. You’re happy to take a Figma mock-up, build the UI, hook it to an API, write tests, and watch the metrics after launch.
- Use AI as leverage. Cursor, Claude, ChatGPT, or your own prompts speed up routine work – and you always verify the output before merging.
- Write things down. Clear design notes, API contracts, and post-mortems come naturally, so the team learns even when you’re offline.
- Chase measurable wins. Lowering latency, raising accessibility scores, and shrinking error rates motivates you more than adding shiny tech.
- Mentor by example. You enjoy code reviews, pairing, and short tech talks that lift junior engineers and interns.
- Learn quickly. A new cloud service, testing tool, or LLM framework is an opportunity, not a hurdle.
- Care about developer impact. Helping millions of candidates show their best code feels rewarding, not abstract.

What you bring

- 3–6 years shipping production software, front end and back end. You have owned code in production, not just assisted.
- Expertise in React / Next.js with TypeScript plus one server language. Go, Node, or Python preferred; Java acceptable. Your portfolio shows complex SPAs or SSR apps and matching REST / gRPC APIs, with typed patterns and modern React hooks.
- Proven micro-service design and tuning. You have broken monoliths, added queues, or pushed a service to hundreds of requests per second—and kept the metrics to prove the gain.
- Daily use of AI development tools. Cursor, Copilot, ChatGPT, Claude, or similar speed up your coding, testing, and documentation.
- Strong SQL and NoSQL skills. You choose the right data model, add indexes, rewrite slow queries, and can quote the performance boost.
- Bonus: Hands-on Docker / Kubernetes and cloud deployments. You package, roll out, and roll back services in AWS, GCP, or Azure without waiting on DevOps.
- Bonus: Built-in observability mindset. Logs, metrics, and traces go in with the feature. You have real-world wins using Prometheus, Grafana, Datadog, or New Relic.