Dataford
Interview QuestionsInterview GuidesExperiencesCoaching
New
Pricing
Get started
Dataford
Popular roles
Software EngineerData AnalystData ScientistData EngineerBusiness AnalystAI EngineerMachine Learning EngineerProduct Manager
Browse
Browse All RolesEvery role hub, from analyst to MLBrowse All CompaniesCompany-specific interview loopsAll Interview GuidesThe full guide library
Top questions by role
Software EngineerData AnalystData ScientistData EngineerBusiness AnalystAI EngineerMachine Learning EngineerProduct Manager
Top questions by skill
SQLPythonStatisticsMachine LearningA/B TestingSystem DesignGenerative AIProduct SenseMetricsBehavioral
Browse all questions →Try a mock interview
Experiences
Practice
Mock InterviewsTimed interview simulations with feedbackCoaching1:1 coaching with people at your target companiesSuccess PathYour 6-week structured planModulesCurated lessons by topicWebinarsTalks from ex-Big Tech data leadsPlaygroundA free-form scratch editor
Learn
BlogInterview strategy and career adviceTech Job Market ReportHiring trends across data and AI rolesFor UniversitiesDataford for career centersAbout DatafordWho we are and how we build
Pricing
Build my plan

Production-Ready Ruby Improvements

MediumCoding00:00
Practice interviewer
In session
5 left
00:00

Your question is Production-Ready Ruby Improvements. Take a moment with it on the right.

Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).

You need to log in / sign up to chat or submit.

Problem

You're an engineer at Betterup, a coaching platform. This service object schedules a coaching session between a member and their coach. It's part of a take-home exercise and works in the happy-path demo, but the reviewer flagged it as not production ready.

class SessionScheduler
  def initialize(member, coach, requested_time, duration)
    @member = member
    @coach = coach
    @requested_time = requested_time
    @duration = duration
  end

  def call
    calendar_event = CalendarApi.create_event(@coach.email, @requested_time)

    session = Session.create!(
      member_id: @member.id,
      coach_id: @coach.id,
      scheduled_at: @requested_time,
      duration_minutes: 60,
      calendar_event_id: calendar_event.id
    )

    @member.update!(credits: @member.credits - 1)

    @member.past_sessions.each do |past|
      puts "previous coach: #{past.coach.name}"
    end

    session
  end
end

What things would you do to this code to get it production ready? Explain each change and why it matters before this runs against real members and real billing.