Complete Hiring Loop:

HR reached out on Linkedin -> Recruiter Screen → 60-min OA → Hiring Manager Round → C1 Tech Round → C2 Tech Round → Offer 🍾🥂

Recruiter Screen — 30–45 Minutes

The recruiter started by asking about background and previous work experience.

Topics included:

• Current and previous projects
• Technologies and tech stack
• The most challenging project he had worked on
• The scale of the system he was currently working on
• Why he was considering a job change
• What he was looking for in his next role
• Compensation expectations

The recruiter also gave a short presentation about Fivetran, including what the company does and how its products serve customers.

Online Assessment — 60 Minutes

Moving on to HM round around two or three days after completing (passed) the assessment

Hiring Manager Round — ~45 Minutes

The first 30 minutes were primarily a deep dive into the current project.

The hiring manager asked about:

• What the project did
• Technologies used
• System architecture
• Technical challenges encountered during development

The candidate discussed a warehouse-space booking system that they had built from scratch. The system allowed vendors and sellers to reserve warehouse space.

Because the project involved concurrent operations, the hiring manager specifically asked about:

• How concurrency was handled in the system
• How threading worked in the application

The round also included behavioral questions such as:

• Tell me about a time you helped another team even though it was not your responsibility.
• Tell me about a time you disagreed with your manager and how you handled it.
• Tell me about a project that went past its deadline.

C1 Technical Round — 60 Minutes

This round combined a coding problem with Java fundamentals.

Coding Problem — Unique Pairs

The candidate was given:

• An integer array
• A target value

Goal was to find unique pairs satisfying the target condition with an additional constraint involving a difference <= 1.

This problem was approximately medium difficulty and had 13 test cases.

Java Follow-Ups

Topics included:

• Java Collections
• How HashMap works internally
• Hash collisions and how they are handled
• Time complexity of insertion, deletion, and lookup
• Java multithreading
• Java memory management

C2 Technical Round

The candidate described C2 as more difficult than C1, and there were two coding problems were asked.

Problem 1 — Connected Groups

The candidate was given a binary relationship matrix containing 0s and 1s.

A 1 indicated that two people were connected, while a 0 indicated that they were not directly connected.

Connections were transitive. For example, if A was connected to B and B was connected to C, then A, B, and C belonged to the same group.

The task was to determine the total number of independent groups.

The candidate described the problem as similar to Number of Islands / connected components.

They passed all 13 test cases.

Problem 2 — Multithreaded Employee Count

The candidate was given a list of employees. Each employee contained information similar to:

Employee
- id
- name
- city

A target city was also provided.

The task was to efficiently determine how many employees lived in that city.

The important requirement was that the solution had to use multithreading.

After the candidate completed the implementation, the interviewer continued with several follow-up questions about:

• Multithreading
• Concurrency
• Related Java concepts

Result — Offer 🤩

Around two or three days after completing C2, the recruiter contacted the candidate and told them that the interview feedback had been very positive and that Fivetran wanted to move forward with an offer. They then discussed compensation.

Approximately one week later, the candidate received the formal offer.

Key Takeaways

This interview was particularly heavy on Java, concurrency, and multithreading.

Concurrency appeared repeatedly throughout the process:

• The hiring manager explored concurrency and threading through the candidate’s own project.
• C1 included explicit questions about Java multithreading and memory management.
• C2 included a coding problem that specifically required a multithreaded solution.
• The multithreaded coding problem was followed by additional concurrency questions.

This makes the experience particularly relevant for candidates preparing for backend or Java-focused Fivetran engineering roles.

I will be back later to update the coding question part 👋