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  <xs:element id="pega_PercentageOfUnbilledReceivablesNotBillableContractDateYearThree" abstract="false" name="PercentageOfUnbilledReceivablesNotBillableContractDateYearThree" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="pega_PercentageOfUnbilledReceivablesNotBillableContractDateYearFourAndPrior" abstract="false" name="PercentageOfUnbilledReceivablesNotBillableContractDateYearFourAndPrior" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="pega_RichardH.JonesMember" abstract="true" name="RichardH.JonesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pega_UnbilledReceivablesCurrentAndNonCurrent" abstract="false" name="UnbilledReceivablesCurrentAndNonCurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pega_PerformanceStockOptionsMember" abstract="true" name="PerformanceStockOptionsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pega_UnbilledReceivablesNotBillableContractDateYearThree" abstract="false" name="UnbilledReceivablesNotBillableContractDateYearThree" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pega_CostOfRevenueMember" abstract="true" name="CostOfRevenueMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="pega_PercentageOfUnbilledReceivablesNotBillableAmountExpectedToBeCollectedInRemainderOfFiscalYear" abstract="false" name="PercentageOfUnbilledReceivablesNotBillableAmountExpectedToBeCollectedInRemainderOfFiscalYear" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="pega_UnbilledReceivablesNotBillableAtBalanceSheetDateAmountExpectedToBeCollectedWithinYearTwoAndFive" abstract="false" name="UnbilledReceivablesNotBillableAtBalanceSheetDateAmountExpectedToBeCollectedWithinYearTwoAndFive" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pega_OtherAssetsAndLiabilitiesAbstract" abstract="true" name="OtherAssetsAndLiabilitiesAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="pega_AccruedCloudHostingCurrent" abstract="false" name="AccruedCloudHostingCurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pega_UnbilledReceivablesNotBillableAtBalanceSheetDateExpectedPercentageToBeCollectedWithinYearTwoAndFive" abstract="false" name="UnbilledReceivablesNotBillableAtBalanceSheetDateExpectedPercentageToBeCollectedWithinYearTwoAndFive" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="pega_OtherLongTermAssets" abstract="false" name="OtherLongTermAssets" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pega_ShareBasedCompensationArrangementByShareBasedPaymentAwardCompensationPercentageOfTargetIncentiveCompensationEligibleToElectAndReceiveByEmployees" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardCompensationPercentageOfTargetIncentiveCompensationEligibleToElectAndReceiveByEmployees" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="pega_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisFairValueAdjustmentIncludedInOtherIncomeNet" abstract="false" name="FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisFairValueAdjustmentIncludedInOtherIncomeNet" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pega_OtherAssetsCurrentAbstract" abstract="true" name="OtherAssetsCurrentAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="pega_UnbilledReceivablesNotBillableAtBalanceSheetDateAmountExpectedToBeCollectedWithinYearOneOrLess" abstract="false" name="UnbilledReceivablesNotBillableAtBalanceSheetDateAmountExpectedToBeCollectedWithinYearOneOrLess" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pega_PerpetualLicenseMember" abstract="true" name="PerpetualLicenseMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="pega_ContractAssetsAndDeferredRevenueTableTextBlock" abstract="false" name="ContractAssetsAndDeferredRevenueTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:textBlockItemType"/>
  <xs:element id="pega_SubscriptionLicenseMember" abstract="true" name="SubscriptionLicenseMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="pega_CreditAgreementMember" abstract="true" name="CreditAgreementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="pega_PercentageOfUnbilledReceivablesNotBillableContractDateYearOne" abstract="false" name="PercentageOfUnbilledReceivablesNotBillableContractDateYearOne" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="pega_RichardH.JonesRuleTradingArrangementCommonStockMember" abstract="true" name="RichardH.JonesRuleTradingArrangementCommonStockMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="pega_DeferredCostsNetTextBlock" abstract="false" name="DeferredCostsNetTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:textBlockItemType"/>
  <xs:element id="pega_PrincipalAndInterestLongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear" abstract="false" name="PrincipalAndInterestLongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pega_UnbilledReceivablesCurrentAndNonCurrentPercentage" abstract="false" name="UnbilledReceivablesCurrentAndNonCurrentPercentage" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="pega_DebtInstrumentCovenantsLeverageRatioMaximum" abstract="false" name="DebtInstrumentCovenantsLeverageRatioMaximum" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
  <xs:element id="pega_OtherLongTermLiabilities" abstract="false" name="OtherLongTermLiabilities" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pega_ConsultingMember" abstract="true" name="ConsultingMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="pega_AccruedCompensationAndRelatedExpenses" abstract="false" name="AccruedCompensationAndRelatedExpenses" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pega_DebtConversionConvertedInstrumentSharesOutstanding" abstract="false" name="DebtConversionConvertedInstrumentSharesOutstanding" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="pega_UnbilledReceivablesNotBillableAtBalanceSheetDateAmountExpectedToBeCollectedWithinYearOneAndTwo" abstract="false" name="UnbilledReceivablesNotBillableAtBalanceSheetDateAmountExpectedToBeCollectedWithinYearOneAndTwo" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pega_OtherCurrentAssets" abstract="false" name="OtherCurrentAssets" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pega_InterestLongTermDebtMaturitiesRepaymentsOfPrincipalYearOne" abstract="false" name="InterestLongTermDebtMaturitiesRepaymentsOfPrincipalYearOne" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pega_LegalFeesPostJudgementInterestRatePercentage" abstract="false" name="LegalFeesPostJudgementInterestRatePercentage" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="pega_ScheduleOfAmortizationOfDeferredCostsTableTextBlock" abstract="false" name="ScheduleOfAmortizationOfDeferredCostsTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:textBlockItemType"/>
  <xs:element id="pega_EarningsPerShareLineItems" abstract="true" name="EarningsPerShareLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="pega_PrincipalAndInterestLongTermDebtMaturitiesRepaymentsOfPrincipalYearOne" abstract="false" name="PrincipalAndInterestLongTermDebtMaturitiesRepaymentsOfPrincipalYearOne" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pega_DebtConversionConvertedInstrumentSharesIfFullyExercised" abstract="false" name="DebtConversionConvertedInstrumentSharesIfFullyExercised" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="pega_UnbilledReceivablesNotBillableContractDateYearFourAndPrior" abstract="false" name="UnbilledReceivablesNotBillableContractDateYearFourAndPrior" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pega_UnbilledReceivablesNotBillableContractDateRemainderOfFiscalYear" abstract="false" name="UnbilledReceivablesNotBillableContractDateRemainderOfFiscalYear" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pega_IndirectTaxReceivable" abstract="false" name="IndirectTaxReceivable" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pega_ViolationOfTheVirginiaComputerCrimesActMember" abstract="true" name="ViolationOfTheVirginiaComputerCrimesActMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="pega_AppianCorpVPegasystemsIncYouyongZouMember" abstract="true" name="AppianCorpVPegasystemsIncYouyongZouMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="pega_CorporateIncentiveCompensationPlanMember" abstract="true" name="CorporateIncentiveCompensationPlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="pega_PegaCloudMember" abstract="true" name="PegaCloudMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="pega_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisCurrencyTranslationAdjustment" abstract="false" name="FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisCurrencyTranslationAdjustment" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pega_AccountsReceivableAndUnbilledReceivable" abstract="false" name="AccountsReceivableAndUnbilledReceivable" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="pega_InvestmentsInPrivatelyHeldCompaniesMember" abstract="true" name="InvestmentsInPrivatelyHeldCompaniesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="pega_SummaryOfUnbilledReceivablesBasedUponContractEffectiveDateTableTextBlock" abstract="false" name="SummaryOfUnbilledReceivablesBasedUponContractEffectiveDateTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:textBlockItemType"/>
  <xs:element id="pega_TradeSecretMisappropriationMember" abstract="true" name="TradeSecretMisappropriationMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="pega_OtherAmericasMember" abstract="true" name="OtherAmericasMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
</xs:schema>
