CRM System - Object-Oriented Design for a Customer Relationship Manager
Question Details
Round 1 OOD / Coding
Problem
Design the core of a CRM system. The system tracks Contacts, Companies, and Deals. A Contact belongs to a Company. A Deal has an associated Contact, a value, and a stage (LEAD, QUALIFIED, CLOSED_WON, CLOSED_LOST). Implement the following:
python
class CRMSystem:
def add_company(self, company_id: str, name: str) -> None: ...
def add_contact(self, contact_id: str, name: str, company_id: str) -> None: ...
def create_deal(self, deal_id: str, contact_id: str, value: float) -> None: ...
def advance_stage(self, deal_id: str) -> str: ...
def total_pipeline_value(self, stage: str) -> float: ...
def deals_for_company(self, company_id: str) -> list[dict]: ...
Example
crm.add_company("c1", "Acme")
crm.add_contact("p1", "Alice", "c1")
crm.create_deal("d1", "p1", 10000.0) # stage = LEAD
crm.advance_stage("d1") # -> "QUALIFIED"
crm.total_pipeline_value("QUALIFIED") # -> 10000.0
crm.deals_for_company("c1") # -> [{deal_id, value, stage, contact}]
Follow-ups
- How would you implement deal history so you can see when each stage transition happened?
- A contact can move to a different company — how does that affect existing deals?
- Design an activity log (calls, emails, notes) attached to deals or contacts.
- How would you generate a sales funnel report showing conversion rates between stages?
Full Details
Round 1 OOD / Coding
Problem
Design the core of a CRM system. The system tracks Contacts, Companies, and Deals. A Contact belongs to a Company. A Deal has an associated Contact, a value, and a stage (LEAD, QUALIFIED, CLOSED_WON, CLOSED_LOST). Implement the following:
python
class CRMSystem:
def add_company(self, company_id: str, name: str) -> None: ...
def add_contact(self, contact_id: str, name: str, company_id: str) -> None: ...
def create_deal(self, deal_id: str, contact_id: str, value: float) -> None: ...
def advance_stage(self, deal_id: str) -> str: ...
def total_pipeline_value(self, stage: str) -> float: ...
def deals_for_company(self, company_id: str) -> list[dict]: ...
Example
crm.add_company("c1", "Acme")
crm.add_contact("p1", "Alice", "c1")
crm.create_deal("d1", "p1", 10000.0) # stage = LEAD
crm.advance_stage("d1") # -> "QUALIFIED"
crm.total_pipeline_value("QUALIFIED") # -> 10000.0
crm.deals_for_company("c1") # -> [{deal_id, value, stage, contact}]
Follow-ups
- How would you implement deal history so you can see when each stage transition happened?
- A contact can move to a different company — how does that affect existing deals?
- Design an activity log (calls, emails, notes) attached to deals or contacts.
- How would you generate a sales funnel report showing conversion rates between stages?
About This Question
This is a reported interview question from a reevo interview during the onsite round.
About Reevo Interview Reports
This question was reported by a candidate who interviewed at Reevo. LeakCode aggregates interview reports from 10+ sources, including 1Point3Acres, Glassdoor, LeetCode Discuss, Blind, Reddit, Indeed, and Nowcoder. Each report is translated where necessary, deduplicated against existing entries, and tagged by company, role, round type, and reporting date.
Use this question as one calibration data point, not a memorization target. Companies typically rotate their question pools every 2-4 months; the exact wording of a 2024 question may differ from what you encounter today. The underlying pattern, difficulty level, and follow-up depth at Reevo are the higher-signal extractions to take from this report.
For broader preparation context, the Reevo interview process typically includes a recruiter screen, one or two technical phone screens, and a 4-5 round on-site loop covering coding, system design (at L4+ levels), and behavioral. Reports tagged on LeakCode show the round-by-round distribution and typical difficulty calibration. To browse questions filtered by round type and seniority, use the company hub linked above.
How To Practice This Type of Question
Solve similar problems on LeetCode under timed conditions (25-35 minutes per medium difficulty). The goal is pattern recognition: recognize the underlying technique (sliding window, two-pointer, BFS, memoized recursion, etc.) within 60-90 seconds of reading. Strong candidates verbalize their hypothesis out loud before coding, then iterate based on feedback. Weak candidates dive into implementation immediately, lose time on the wrong approach, and run out of time for follow-ups.
Companies update their question pools every 2-4 months. The exact wording of any given question may have been retired by the time you interview. Focus your prep on the pattern, not the specific problem. The patterns that appear in Reevo reports consistently are the ones worth investing in; one-off niche problems are not.
During Your Reevo Round
Apply the standard interview round template: clarify requirements (2-3 minutes), state your approach out loud and confirm direction with the interviewer (3-5 minutes), code with narration (15-25 minutes), test with concrete examples including edge cases (5 minutes), discuss optimization or trade-offs if time permits (5 minutes). This template is universally accepted across FAANG and adjacent companies; deviating from it produces weaker interviewer feedback signal.
The single most predictive failure mode in Reevo reports tagged "no hire": not asking clarifying questions. Interviewers are explicitly trained to weight this. Strong candidates ask 3-5 clarifying questions even on problems that look obvious; weak candidates dive into code immediately. The clarifying-question check is often the first signal recorded in the interviewer's written notes.