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Screna has 10 Lead Bank interview write-ups. The most reported round is the technical phone screen (8).

10 interview notes · updated Jul 2026

Lead Bank·Software Engineer·Technical Phone Screen

Jun 2026
Got a coding round for a Software Engineer role at Lead Bank and they threw a versioned key-value store design problem at me. More design-heavy than I expected for what felt like a mid-level screen.
  • Design and implement a versioned key-value store that supports retrieving a value as of a given timestamp, and generating a frozen snapshot of the entire map at a point in time.

“The basic put/get stuff was fine, I used a sorted list of (timestamp, value) pairs per key and binary search for the timestamp lookup.”

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Lead Bank·Software Engineer·Onsite - System Design / Architecture

Jun 2026
System design round at Lead Bank for a software engineer role, focused entirely on a hotel booking system. Two specific deep-dives came up that I wasn't fully prepared for, and one of them genuinely stumped me for a moment.
  • In a hotel booking system, how would you query and return only room types that are available across every single day in a requested date range?
  • At checkout in a hotel booking system, how do you differentiate between a user who genuinely didn't pay versus a user who paid but whose third-party payment confirmation arrived after your timeout threshold?

“This one tripped me up more than I expected.”

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Lead Bank·Software Engineer·Technical Phone Screen

Jun 2026
Coding round for a software engineer role at Lead Bank. One problem, but it had enough moving parts to keep me busy for a while. The friend recommendation logic was the part that tripped me up.
  • You're given a set of edges representing like counts between pairs of users. Implement two things: (a) a query that returns the like count between any two users, and (b) a friend recommendation system. The recommendation works by finding who the target user likes most, then returning that person's most-liked contact. A recommended user can't be the target user themselves, and can't already be a mutual friend. If the top candidate doesn't yield a valid recommendation, fall back to the next-highest liked user and try again. Throw an error if no valid recommendation exists.

“The lookup part was fine, basically just a map.”

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Lead Bank·Software Engineer·Technical Phone Screen

May 2026
Lead Bank SWE interview had a pretty meaty data structures question that required more design thinking than I expected for what felt like a coding round. Not the worst experience, but it made me realize I should brush up on time-space trade-off discussions because they went deep on that.
  • Design a VersionedHashMap that supports put(key, value), get(key), and freeze(timestamp), where freeze returns the state of all key-value pairs at a given point in time. Walk through your data structure choice, time complexity for each operation, and the memory vs. query speed trade-offs.

“I jumped straight to the implementation and started coding before thinking through the design, which bit me.”

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Lead Bank·Software Engineer·Technical Phone Screen

May 2026
Coding round at Lead Bank for a software engineer role. Two parts, both centered around a social likes system. The problems weren't crazy hard but the second part had some tricky graph traversal logic that required careful thinking.
  • Design and implement a data structure for a social likes system that supports two operations: retrieving the like count between two users, and ingesting bidirectional like data between users.
  • Given the social likes data structure from the previous part, implement a friend recommendation function that, for a given user, finds their best friend's best friend (where 'best' is defined by highest like count).

“The transform function part was pretty approachable.”

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Lead Bank·Software Engineer·Technical Phone Screen

May 2026
Coding round at Lead Bank for a software engineer role. One problem with a twist layered on top, which made it more interesting than a straight leetcode grind.
  • Implement a time-based key-value store that supports setting values with timestamps and retrieving the most recent value at or before a given timestamp. Then extend it to support returning a full snapshot of the store at a specific timestamp.

“The base problem I'd seen before so binary search on the timestamps per key came to me pretty fast.”

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Lead Bank·Software Engineer·Technical Phone Screen

May 2026
Coding round at Lead Bank for a software engineer role. The problem was stock prices, broken into four parts, with the last part being optional to just talk through rather than actually code.
  • Solve a stock prices problem across multiple parts (four total), with the final part only requiring a verbal explanation rather than a coded solution.

“Four-parter on stock prices.”

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Lead Bank·Software Engineer·Technical Phone Screen

Apr 2026
Coding round for a Software Engineer role at Lead Bank. The problem wasn't from LeetCode but it wasn't brutal either, just an Event class with some CRUD methods and a complexity discussion at the end.
  • Given an Event class with start_time, end_time, and event_name attributes, implement CRUD methods where the event list stays sorted by start_time. The create method should use binary search to find the correct insertion point.
  • Implement a get method that supports offset and limit parameters to return a specific slice of the sorted event list.
  • What is the time complexity of each of the CRUD methods you implemented?

“Not on LeetCode, which threw me a little.”

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Lead Bank·Software Engineer·Technical Phone Screen

Apr 2026
Lead Bank SWE interview, got a meaty in-memory data store design problem that kept evolving mid-question. Felt like a system design round dressed up as a coding exercise, which I wasn't fully prepared for.
  • Design an in-memory stock price store that supports fetching a stock's price on a given date, returning a sensible result when the data is missing.
  • Implement a price change operation that applies a custom formula between two dates, and handles cases where either price is absent or the formula fails.
  • Add an atomic batch update operation: update prices for a stock over a date range, but fail the entire update if any date in that range was already updated previously.
  • Extend the store to support hourly granularity: add a method that returns all hourly prices for a stock within a given calendar day, ordered by time.
  • Write test cases covering edge cases like duplicate records, missing symbols, invalid date ranges, repeated updates, and date/time parsing issues.

“Started fine, basically a hashmap keyed on symbol and date.”

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Lead Bank·Software Engineer·Onsite - System Design / Architecture

Apr 2026
System design round at Lead Bank for a software engineer role. The whole thing was focused on a hotel reservation system and the interviewer kept pushing on failure scenarios, which apparently went well enough.
  • Design a hotel reservation system. Walk through the architecture and handle various failure scenarios in depth.

“The base design part felt manageable but the failure cases are where it got real.”

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