Engineering Ic interview prep.

Behavioural questions to expect

1. Walk me through your CV.
2. Tell me about your most impactful technical project.
3. Tell me about a weakness, a failure, or feedback you've received and worked on.
4. Why devtools + infrastructure - and why the firm vs consumer / SaaS / hyperscaler?
5. Which team or technical area would you want to work on, and why?
6. Why the firm?
7. How would you describe the firm's engineering organisation + infrastructure in your own words?
8. How does engineering actually drive value at a devtools / infra firm?

Technical concepts to master

• Distributed-systems primitives (infra scale)

  Consensus (Raft / Paxos) · Sharding + multi-tenant isolation · Replication + consistency · Graceful degradation

• API design + backward compat + deprecation

  API design principles · Versioning strategies · Backward compatibility discipline · Deprecation workflow

• Open source + community + governance

  OSS business models · Maintainer responsibilities · Contribution + community discipline · OSS license + governance

• Reliability + SLO + the dependency-layer responsibility

  SLO + customer contract · Blast radius + multi-tenant isolation · Postmortem + customer communication · Change management + canary discipline

Practical drills

• Design capacity for a feature-flag service that serves 1000 customer apps, each handling 10K QPS average / 30K peak. The flag service is called once per request on average. P99 budget 5ms. (a) Total flag-eval QPS. (b) Why local caching is essential. (c) Rough infra need with + without local caching.
• Design a CI/CD orchestration service for the firm. Customers connect their git repos + define pipelines; the service runs them. Walk me through.
• Your kv-store service is alerting on P99 latency spike (50ms → 500ms) across all customers in one region. Walk me through the next 60 minutes.

Smart-question anchors

• Team + scope - the team's surface area, what the role would specifically own in 6-12 months
• API + backward-compat posture - the firm's API design + deprecation discipline, breaking-change policy
• Open source - OSS-led vs open-core vs proprietary; maintainer responsibilities + governance
• On-call + reliability - SLO + error-budget approach, customer-published postmortems, recent incidents
• RFC + design culture - how big architectural decisions are made, who writes + reviews RFCs

Sourced from

interviewing.io + Hello Interview — Senior Engineer System Design · Postman + Devinterview — API Design Interview Questions · Google SRE Book + canonical SRE reference — golden signals + SLOs + dependency-layer reliability · Tech Interview Handbook — Behavioral Interview Questions for SWE · GitHub + open-source maintainer community — governance + community dynamics · GeeksForGeeks + InterviewBit — SRE / Infrastructure interview questions