Personally, I have never paid for a professional mock interview, but if you have the budget, please go for it, many people say it is really beneficial.
People might argue that certifications are useless. However, I personally believe that if you can earn a certification, it means you at least know the basics of how a technology works, especially if the certification is hands-on (not just multiple-choice questions), such as Kubernetes certifications (CKA, CKAD) or Linux certifications (LFCS, RHCSA).
If you can use the company’s budget to get certified, then there’s no harm in doing so, right?
Many interviewers also ask about certifications.
Personally, I have never contributed to any open-source repositories due to time constraints. (I would love to, though! )
In the industry, contributing to open source, especially to a highly valued community such as the CNCF (Cloud Native Computing Foundation), is seen as a strong indicator of skill, collaboration, and commitment to the tech ecosystem.
Such contributions aren’t limited to code; they can also include improving documentation, reporting issues, or sharing ideas. Being involved in these communities often means working alongside talented engineers worldwide and helping shape the tools that many organizations depend on.
Authentication and Authorization
Secrets Management
TLS/SSL and Certificate Management
Infrastructure Security
Container and Kubernetes Security
CI/CD Pipeline Security
Common Vulnerabilities and Exploits
Compliance, Audit, and Security Best Practices
4 Golden Signals: latency, traffic, errors, saturation
3 pillars of observability: metrics, logs, and traces
Threshold-based and anomaly-based alerting
Alert routing, escalation, and severity levels
SLO, SLI, and SLA
Incident handling: detection, triage, communication, resolution, RCA, postmortem
Managing alert fatigue
Visualization with dashboards
Behavioral interviews can sometimes feel unpredictable, but they’re designed to see how you think, make decisions, and work with others. Instead of testing your technical skills directly, they explore your past experiences to predict how you might handle future situations.
From what I’ve seen, the key is to prepare real examples from your own career—both successes and challenges—and structure them using the STAR method (Situation, Task, Action, Result). This makes your answers clear, concise, and memorable.
Most importantly, be honest, show that you can work collaboratively, and demonstrate self-awareness, problem-solving ability, and a growth mindset.