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  <xs:element id="mgni_ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOfferingPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="mgni_CapitalizedComputerSoftwareAmortizationExpenseNextTwelveMonths" abstract="false" name="CapitalizedComputerSoftwareAmortizationExpenseNextTwelveMonths" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_MobileMember" abstract="true" name="MobileMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="mgni_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccountsPayableAndAccruedLiabilities" abstract="false" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAccountsPayableAndAccruedLiabilities" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_DebtDiscountMember" abstract="true" name="DebtDiscountMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="mgni_LineOfCreditFacilityIncreaseInMaximumBorrowingCapacity" abstract="false" name="LineOfCreditFacilityIncreaseInMaximumBorrowingCapacity" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_BusinessAcquisitionEquityInterestIssuedOrIssuableNumberOfSharesAcceleration" abstract="false" name="BusinessAcquisitionEquityInterestIssuedOrIssuableNumberOfSharesAcceleration" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="mgni_BusinessCombinationConsiderationTransferredIndemnificationClaimsHoldback" abstract="false" name="BusinessCombinationConsiderationTransferredIndemnificationClaimsHoldback" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_SalesandMarketingPolicyTextBlock" abstract="false" name="SalesandMarketingPolicyTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="mgni_PercentageOfOutstandingBalanceHoldersAbleToCallDebtInTheEventOfDefault" abstract="false" name="PercentageOfOutstandingBalanceHoldersAbleToCallDebtInTheEventOfDefault" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="mgni_ConnectedTelevisionMember" abstract="true" name="ConnectedTelevisionMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="mgni_BusinessCombinationConsiderationTransferredEquityInterestsIssuableFairValue" abstract="false" name="BusinessCombinationConsiderationTransferredEquityInterestsIssuableFairValue" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_StockIssuedDuringPeriodSharesMerger" abstract="false" name="StockIssuedDuringPeriodSharesMerger" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="mgni_PercentOfCompanyOwnedByHoldersOfAcquiredCompany" abstract="false" name="PercentOfCompanyOwnedByHoldersOfAcquiredCompany" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="mgni_SeniorSecuredRevolvingCreditFacilityMember" abstract="true" name="SeniorSecuredRevolvingCreditFacilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="mgni_BusinessAcquisitionEquityInterestIssuedOrIssuableElectedDecreasePercentage" abstract="false" name="BusinessAcquisitionEquityInterestIssuedOrIssuableElectedDecreasePercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="mgni_CustomerOneMember" abstract="true" name="CustomerOneMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="mgni_DebtInstrumentRedemptionMakeWholeFundamentalChangePeriod" abstract="false" name="DebtInstrumentRedemptionMakeWholeFundamentalChangePeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="mgni_DebtIssuanceCostsDomain" abstract="true" name="DebtIssuanceCostsDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="mgni_DebtInstrumentConversionTermAxis" abstract="true" name="DebtInstrumentConversionTermAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="mgni_OfficeLeaseMember" abstract="true" name="OfficeLeaseMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="mgni_AmortizationOfDebtDiscountPremiumYearFour" abstract="false" name="AmortizationOfDebtDiscountPremiumYearFour" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_TermOfServiceArrangement" abstract="false" name="TermOfServiceArrangement" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="mgni_RestructuringChargesAssumedLossContractsSettledWithoutCash" abstract="false" name="RestructuringChargesAssumedLossContractsSettledWithoutCash" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_RestrictedawardsMember" abstract="true" name="RestrictedawardsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="mgni_LeaseRelatedLossContractsMember" abstract="true" name="LeaseRelatedLossContractsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="mgni_AmortizationOfDebtIssuanceCostsAfterYearFive" abstract="false" name="AmortizationOfDebtIssuanceCostsAfterYearFive" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantedInPeriodFairValue" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantedInPeriodFairValue" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_PaymentsForRestructuringAndMergerRelatedCosts" abstract="false" name="PaymentsForRestructuringAndMergerRelatedCosts" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedAndVestedButDeferredWeightedAverageGrantDateFairValue" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedAndVestedButDeferredWeightedAverageGrantDateFairValue" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:perShareItemType"/>
  <xs:element id="mgni_AmortizationOfDebtIssuanceCostsYearFour" abstract="false" name="AmortizationOfDebtIssuanceCostsYearFour" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_LeaseArrangementsDomain" abstract="true" name="LeaseArrangementsDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="mgni_BusinessCombinationConsiderationTransferredWorkingCapitalAdjustments" abstract="false" name="BusinessCombinationConsiderationTransferredWorkingCapitalAdjustments" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_NumberOfProjects" abstract="false" name="NumberOfProjects" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="mgni_OneSellerMember" abstract="true" name="OneSellerMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="mgni_LeaseArrangementsAxis" abstract="true" name="LeaseArrangementsAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="mgni_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuableRestrictedStockUnitsExchangedPreAcquisition" abstract="false" name="BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuableRestrictedStockUnitsExchangedPreAcquisition" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_DebtInstrumentsCappedCallsTransactionCosts" abstract="false" name="DebtInstrumentsCappedCallsTransactionCosts" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestingStockPriceTrigger" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestingStockPriceTrigger" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:perShareItemType"/>
  <xs:element id="mgni_DebtInstrumentOverAllotmentOptions" abstract="false" name="DebtInstrumentOverAllotmentOptions" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_DeferredIncomeTaxLiabilitiesNetMember" abstract="true" name="DeferredIncomeTaxLiabilitiesNetMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="mgni_StockIssuedDuringPeriodValueMerger" abstract="false" name="StockIssuedDuringPeriodValueMerger" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_DesktopMember" abstract="true" name="DesktopMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="mgni_ShareBasedCompensationArrangementByShareBasedPaymentAwardPerformanceMeasurementPercentage" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardPerformanceMeasurementPercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="mgni_PaymentsToAcquireBusinessesGrossElectedIncreaseAmount" abstract="false" name="PaymentsToAcquireBusinessesGrossElectedIncreaseAmount" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_AmortizationOfDebtDiscountPremiumYearThree" abstract="false" name="AmortizationOfDebtDiscountPremiumYearThree" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_AmortizationOfDebtDiscountPremiumYearFive" abstract="false" name="AmortizationOfDebtDiscountPremiumYearFive" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_ScheduleOfInternalUseSoftwareCostsTableTextBlock" abstract="false" name="ScheduleOfInternalUseSoftwareCostsTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="mgni_LeasesLiabilitiesCurrent" abstract="false" name="LeasesLiabilitiesCurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_DebtInstrumentAnnualPrincipalPaymentPercentage" abstract="false" name="DebtInstrumentAnnualPrincipalPaymentPercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="mgni_BasisOfRevenueRecognitionDomain" abstract="true" name="BasisOfRevenueRecognitionDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="mgni_PerformanceSharesGrantedApril2020Member" abstract="true" name="PerformanceSharesGrantedApril2020Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="mgni_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLeaseNoncurrentLiabilities" abstract="false" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLeaseNoncurrentLiabilities" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_IndemnificationClaimAccrualCurrent" abstract="false" name="IndemnificationClaimAccrualCurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_ServeMotionIncMember" abstract="true" name="ServeMotionIncMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="mgni_BusinessAcquisitionEquityInterestIssuedOrIssuableNumberOfSharesAdditionallyWithAcceleration" abstract="false" name="BusinessAcquisitionEquityInterestIssuedOrIssuableNumberOfSharesAdditionallyWithAcceleration" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="mgni_EmployeeSeveranceAndOneTimeTerminationBenefitsMember" abstract="true" name="EmployeeSeveranceAndOneTimeTerminationBenefitsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="mgni_CustomerTwoMember" abstract="true" name="CustomerTwoMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="mgni_BusinessAcquisitionNetOperatingLossFederal" abstract="false" name="BusinessAcquisitionNetOperatingLossFederal" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_EvergreenAnnualIncrease" abstract="false" name="EvergreenAnnualIncrease" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="mgni_SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsExercisesinPeriodGross" abstract="false" name="SharebasedCompensationArrangementbySharebasedPaymentAwardOptionsExercisesinPeriodGross" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="mgni_ConversionTermIvMember" abstract="true" name="ConversionTermIvMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="mgni_InternalUseSoftwareDevelopmentCostsWriteoffs" abstract="false" name="InternalUseSoftwareDevelopmentCostsWriteoffs" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_DebtInstrumentPeriodicPaymentPercentageOfPrincipal" abstract="false" name="DebtInstrumentPeriodicPaymentPercentageOfPrincipal" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="mgni_DeferredTaxAssetLeaseLiability" abstract="false" name="DeferredTaxAssetLeaseLiability" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_RestructuringReserveAndBusinessCombinationAcquisitionRelatedCosts" abstract="false" name="RestructuringReserveAndBusinessCombinationAcquisitionRelatedCosts" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_LeasesLiabilitiesNoncurrent" abstract="false" name="LeasesLiabilitiesNoncurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_AccretionOfAvailableForSaleSecurities" abstract="false" name="AccretionOfAvailableForSaleSecurities" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_AccountsReceivableAllowanceForCreditLossMergerAssumed" abstract="false" name="AccountsReceivableAllowanceForCreditLossMergerAssumed" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_BusinessAcquisitionNetOperatingLossState" abstract="false" name="BusinessAcquisitionNetOperatingLossState" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_DebtDiscountReceivedDuringNoncashOrPartialNoncashTransaction" abstract="false" name="DebtDiscountReceivedDuringNoncashOrPartialNoncashTransaction" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_LineOfCreditFacilityCovenantComplianceDebtUtilizationTriggeringLeverageRatioCompliancePercentage" abstract="false" name="LineOfCreditFacilityCovenantComplianceDebtUtilizationTriggeringLeverageRatioCompliancePercentage" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="mgni_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsUnvestedAndVestedButDeferredNumber" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsUnvestedAndVestedButDeferredNumber" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="mgni_DebtInstrumentConversionTermDomain" abstract="true" name="DebtInstrumentConversionTermDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="mgni_BusinessCombinationConsiderationTransferredBeforeWorkingCapitalAdjustments" abstract="false" name="BusinessCombinationConsiderationTransferredBeforeWorkingCapitalAdjustments" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_GrossRevenueMember" abstract="true" name="GrossRevenueMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="mgni_A2014EmployeeStockPurchasePlanMember" abstract="true" name="A2014EmployeeStockPurchasePlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="mgni_NthPartyLtdMember" abstract="true" name="NthPartyLtdMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="mgni_PaymentsToAcquireBusinessesGrossElectedIncreasePercentage" abstract="false" name="PaymentsToAcquireBusinessesGrossElectedIncreasePercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="mgni_InternalUseSoftwareDevelopmentCostsNet" abstract="false" name="InternalUseSoftwareDevelopmentCostsNet" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_NonCashLeaseExpense" abstract="false" name="NonCashLeaseExpense" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_AccountsPayableSeller" abstract="false" name="AccountsPayableSeller" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="mgni_NetRevenueMember" abstract="true" name="NetRevenueMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="mgni_ConversionTermIMember" abstract="true" name="ConversionTermIMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
</xs:schema>
