Goldman Sachs Interview Process - Junior Fullstack Engineer

I got an offer for a Fullstack Engineer role at Goldman Sachs. There were six rounds: a HackerRank test, a CoderPad interview, a three-round Superday and a final design round.

Round 1: HackerRank

Three coding problems, mostly medium DSA and implementation. I don't remember the exact ones. Not too tough, but you need to be quick and accurate.

Round 2: CoderPad

Live coding plus discussion. The main problem: you get two arrays, one of process IDs and one of their parent IDs. Given a target process, kill it and all of its children. I treated the processes as a tree and used BFS/DFS.

After that we talked about my recent Spring Boot projects, Java concurrency basics and handling scalability in distributed systems.

Superday (Rounds 3 to 5)

Three back-to-back virtual interviews.

Round 3: DSA

• A problem similar to Valid Palindrome II: can a string become a palindrome by removing at most one character?

• A greedy problem at about LeetCode hard level, with constraints to work around.

Thinking out loud and explaining trade-offs while coding mattered a lot here.

Round 4: Git, a mini HLD and DSA

• Git branching in real projects: feature branches, release flow and hotfixes.

• A mini HLD: the interviewer picked one component of a larger system and asked how I'd design it.

• Restore IP Addresses (backtracking).

This was the most fun round, a good mix of practical engineering and algorithms.

Round 5: Concurrency and graphs

• Number of Islands, with DFS or Union Find.

• Handling lots of incoming requests with a ThreadPool.

• Concurrency in more depth: locks, race conditions, BlockingQueue, thread safety, scaling requests and avoiding bottlenecks.

Round 6: LLD, HLD and databases

• LLD and HLD of an e-commerce platform: cart, orders and payments, plus scaling and reliability.

• How database indexing works internally.

• How NoSQL stores data and optimizes queries.

• SQL vs NoSQL trade-offs in real scenarios.

Outcome

I got the offer a few weeks later 🎉

Tips

• DSA: standard LeetCode, especially graphs, strings and backtracking.

• Java: thread pools, synchronization and how concurrency works in backend systems, on top of core Java.

• System design: prepare both HLD and LLD. E-commerce, notification systems and caching come up a lot.

• Git and engineering practice: branching, CI/CD basics and deployments.