I applied for the Software Development Engineer I (Data) role at Safe Security through their careers page. After about two weeks, I received an email from the recruiter to schedule interviews, which involved a total of 4 virtual rounds.

Initial Screening (15 Mins)

This was a short Google Meet call where the recruiter asked me about my motivations for looking for a change and the scale of systems I had worked on. Following that, they delved into CS fundamentals with placement-style questions, covering topics like TCP vs UDP, SQL vs NoSQL, and basic OS concepts. These were straightforward to answer. I was also asked to rate my hardworking level on a scale of 0-10.

Technical Round 1 with a Senior Engineer (60 Mins)

The first 35 minutes of this round involved a deep discussion on data engineering fundamentals and related technologies. The senior engineer posed situational questions such as “Which approach would you choose for X latency/throughput constraints?” and explored trade-offs concerning cost, latency, and durability. We had an in-depth conversation around these concepts.

For the remaining 20 minutes, I tackled two problems:

• DSA: I was asked to provide the complete optimized code and complexity analysis for the Longest Common Subsequence problem.
• SQL: I had to write an SQL query to “Return a list of users who have actually spent > 10,000 in total,” which involved using basic joins, GROUP BY, and HAVING clauses.

Technical Round 2 with Manager (60 Mins)

This round began with a question about how I would rate my hardworking level on a scale of 1-10 (their expectation seemed to be 10). We then did a deep dive into my past projects, discussing challenges I faced, trade-offs I made, and what aspects I owned. This was followed by a quick, random question: “What happens when we type google.com?” where I covered networking, DNS, TLS handshake, and CDN caching.

The system design portion focused on designing a parking lot system. I discussed functional and non-functional requirements, database design (including table schemas and indexes), choosing between RDBMS and NoSQL, and table layouts.

Finally, I was given a situational data-pipeline design problem: “Design a pipeline for high throughput (both read & write scaled).” I was expected to discuss partitioning, sharding, message queuing, batching, backpressure, scaling read replicas, cache strategies, and monitoring.

HR alignment + CEO connect

Before my CEO connect, HR validated my behavioral answers and subtly nudged some of my responses during a 15-minute call.

The final 30-minute session with the CEO was very conversational. We discussed my intro, tech experience, achievements, family background, a pride moment, and various behavioral questions.

The Offer

I received a strong compensation offer, and the role itself aligned well with my interests. However, after comparing my interview experiences with public discussions about the company, I realized that the day-to-day environment might not align with my desired work-life balance. While I am extremely dedicated when necessary, I also value boundaries, and I didn't feel Safe Security would accommodate that. Consequently, I decided to reject the offer.