Agoda Staff Software Engineer Interview Experience
Anonymous User
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Interview

Recently interviewed with Agoda for Staff Software Engineer role. Could not clear the system design/platform round. Sharing the questions and discussion topics for others preparing for senior backend/platform roles.

Round 1 — Coding Round (60 mins)

Question 1 — Simple Chemical Formula Evaluation

Write a function:

calculateWeight(String formula)

Requirements:

  • Supported elements:

    • C → 12
    • H → 1
    • O → 8

  • No parentheses

  • Single-digit multipliers only

Example:

Input:
CH4

Output:
16

Explanation:
C = 12
H4 = 1 × 4 = 4
Total = 16

Question 2 — Complex Chemical Formula Evaluation

Enhancement over previous problem:

  • Nested parentheses supported
  • Multipliers after parentheses apply to entire group

Examples:

Input:
H(CH4)2

Output:
33

Input:
((CH4))

Output:
16

Main concepts:

  • Stack
  • Parsing
  • Recursive/group evaluation

Round 2 — Platform/System Design Round (60 mins)

Architecture Problem

Scenario:
A booking platform needs to expose APIs for external suppliers to fetch booking information.

Requirements:

  • Support 10–20 suppliers

  • Suppliers fetch bookings using different filters:

    • last 5 minutes
    • last 2 hours
    • last 1 day
    • next 7 days check-ins
    • next 30 days check-ins

  • Peak traffic:

    • ~100 requests/minute

Existing proposal from team:

  • External Booking API calls internal Booking API
  • New endpoint fetches bookings by supplier ID and date range

Main discussion areas:

  • Why external APIs should not directly hit core booking service
  • Read replicas vs OLTP DB
  • CDC/event streaming
  • Pagination and cursor-based APIs
  • Incremental sync tokens
  • Rate limiting/throttling
  • Caching strategy
  • Security/authentication
  • Supplier isolation

Architecture topics interviewer focused on:

  • Scalability
  • Loose coupling
  • External API design
  • Data synchronization
  • Production readiness

Code Review Discussion

Second part of round involved reviewing Java code for supplier booking query API.

Focus areas:

  • Clean code principles
  • Single Responsibility Principle
  • Dependency Injection
  • Removing duplicate cache logic
  • Enum-based behavior encapsulation
  • Validation cleanup
  • Exception handling
  • Logging practices
  • Cache key design
  • Separation of mapper responsibilities

Interview was heavily focused on:

  • Backend architecture thinking
  • Maintainability
  • Real-world production systems
  • Senior/staff-level engineering judgment

Hope this helps others preparing for Agoda platform/backend interviews.

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