**Exhibit 31.1**

 

**CERTIFICATION OF CHIEF EXECUTIVE OFFICER AS ADOPTED PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002**

 

I, James T. Demetriades,certify that:

 

1.                                       I have reviewed this quarterlyreport on Form 10-Q of SeeBeyond Technology Corporation.

 

2.                                       Based on my knowledge, thisreport does not contain any untrue statement of material fact or omit to statea material fact necessary to make the statements made, in light of thecircumstances under which such statements were made, not misleading withrespect to the period covered by this report.

 

3.                                       Based on my knowledge, thefinancial statements, and other financial information included in this report,fairly present in all material respects the financial condition, results ofoperations and cash flows of the registrant as of, and for, the periodspresented in this report;

 

4.                                       The registrant’s othercertifying officer(s) and I are responsible for establishing and maintainingdisclosure controls and procedures (as defined in Exchange ActRules 13a-15(e) and 15d-15(e)) for the registrant and have:

 

(a)  Designed suchdisclosure controls and procedures, or caused such disclosure controls andprocedures to be designed under our supervision, to ensure that materialinformation relating to the registrant, including its consolidatedsubsidiaries, is made known to us by others within those entities, particularlyduring the period in which this report is being prepared;

 

(b)  Evaluated theeffectiveness of the registrant’s disclosure controls and procedures presentedin this report our conclusions about the effectiveness of the disclosurecontrols and procedures; and

 

(c)  Disclosed in thisreport any change in the registrant’s internal control over financial reportingthat occurred during the registrant’s most recent fiscal quarter (theregistrant’s fourth fiscal quarter in the case of an annual report) that hasmaterially affected, or is reasonably likely to materially affect, theregistrant’s internal control over financial reporting; and

 

5.                                       The registrant’s othercertifying officer(s) and I have disclosed, based on our most recent evaluationof internal control over financial reporting, to the registrant’s auditors andthe audit committee of the registrant’s board of directors (or personsperforming the equivalent functions):

 

(a)  All significantdeficiencies and material weaknesses in the design or operation of internalcontrol over financial reporting which are reasonably likely to adverselyaffect the registrant’s ability to record, process, summarize and reportfinancial information; and

 

(b)  Any fraud, whetheror not material, that involves management or other employees who have asignificant role in the registrant’s internal control over financial reporting.

 

Date:    November14, 2003

 

 
| By:    | /s/   JAMES T.  DEMETRIADES |   |
|--------|---------------------------------------|--------|
| Name:  | James T. Demetriades                  |
| Title: | *Chief  Executive Officer*            |

 

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**CERTIFICATION OF CHIEF FINANCIAL OFFICER**

**AS ADOPTED PURSUANT TO**

**SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002**

 

I, Barry J. Plaga, certifythat:

 

1.                                       I have reviewed this quarterlyreport on Form 10-Q of SeeBeyond Technology Corporation.

 

2.                                       Based on my knowledge, thisreport does not contain any untrue statement of material fact or omit to statea material fact necessary to make the statements made, in light of thecircumstances under which such statements were made, not misleading withrespect to the period covered by this report.

 

3.                                       Based on my knowledge, thefinancial statements, and other financial information included in this report,fairly present in all material respects the financial condition, results ofoperations and cash flows of the registrant as of, and for, the periodspresented in this report;

 

4.                                       The registrant’s othercertifying officer(s) and I are responsible for establishing and maintainingdisclosure controls and procedures (as defined in Exchange ActRules 13a-15(e) and 15d-15(e)) for the registrant and have:

 

(a)  Designed suchdisclosure controls and procedures, or caused such disclosure controls andprocedures to be designed under our supervision, to ensure that materialinformation relating to the registrant, including its consolidatedsubsidiaries, is made known to us by others within those entities, particularlyduring the period in which this report is being prepared;

 

(b)  Evaluated theeffectiveness of the registrant’s disclosure controls and procedures presented in this report our conclusions about the effectiveness of thedisclosure controls and procedures;

 

(c)  Disclosed in thisreport any change in the registrant’s internal control over financial reportingthat occurred during the registrant’s most recent fiscal quarter (theregistrant’s fourth fiscal quarter in the case of an annual report) that hasmaterially affected, or is reasonably likely to materially affect, theregistrant’s internal control over financial reporting; and

 

5.                                       The registrant’s other certifyingofficer(s) and I have disclosed, based on our most recent evaluation ofinternal control over financial reporting, to the registrant’s auditors and theaudit committee of the registrant’s board of directors (or persons performingthe equivalent functions):

 

(a)  All significantdeficiencies and material weaknesses in the design or operation of internalcontrol over financial reporting which are reasonably likely to adverselyaffect the registrant’s ability to record, process, summarize and report financialinformation; and

 

(b)  Any fraud, whetheror not material, that involves management or other employees who have asignificant role in the registrant’s internal control over financial reporting.

 

Date:    November 14, 2003

 

 
| By:    | /s/   BARRY J.  PLAGA |   |
|--------|---------------------------------|--------|
| Name:  | Barry J. Plaga                  |
| Title: | *Chief  Financial Officer*      |

 

 

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