Exhibit 10.16

Jeffrey G. Barnett

Dear Jeff:

On behalf of Demandware, Inc. (the “Company”), I am pleased to confirm our employment offer to you for the position of SVP Field Operations. In that position you will be responsible for, among other things, Sales and Services which include Sales, Professional Services, Partner Enablement, Training and Technical Support. Your starting salary will be 175,000 dollars, payable semi monthly (annualized) and your employment will commence as soon as convenient for you but no later than November 7.

In addition to the annual salary specified above, you are eligible to earn annual incentive bonuses totally $125,000. These bonuses will be based on the achievement of mutually agreed upon milestones or objectives and will be paid at least quarterly.

Subject to Board approval, you will be granted 574,526 options to purchase shares of Demandware, Inc. common stock pursuant to our Employee Stock Option Plan. This represents 4% of the outstanding common and preferred shares outstanding prior to our Series B financing. Subsequent to the successful completion of our Series B financing, you will receive an additional grant which will be a calculated amount such that the total number of options issued by way of the two grants will equate to the same 4%. The exercise price of the options will be set at the fair market value as of the date of grant (which we anticipate will correspond with the date your employment commences). The options shall be granted to you subject to the terms and conditions of the Employee Stock Option Plan and the attached Employee Stock Option Agreement, which must be executed on or before the date of grant. As more fully spelled out in the Employee Stock Option Agreement, both option grants shall vest as follows: twenty-five percent (25%) of the options on the one (1) year anniversary of your employment; and one forty-eighth (l/48th) of the options at the end of each month starting with the thirteenth (13th) month following the start date of your employment. Additionally, also subject to board approval, you are eligible to purchase up to 200,000 shares of Series-B preferred stock as part of the Series-B financing round. Your options will include a term which will provide for an acceleration of 12 months of vesting should there be a Sale Event and your employment, where employment is at least equivalent in terms of role, scope of responsibilities and compensation, is not continued within 12 months of that event.

You will be eligible to participate in all other employee welfare benefit plans generally made available by the Company to similarly-situated employees. Your participation will be in accordance with the plan rules and regulations as to eligibility, waiting periods etc. While these plans are subject to change without notice, they generally include medical, dental, short term and long term disability insurance as well as $50,000 of life insurance. In addition you may elect to participate in the Demandware 401K plan as well as a flexible spending plan (Section 125 Plan).

Initially you will be entitled to up to 25 Paid Time Off Days (PTO days) each year. These days may be used for vacation. They must also be used for days absent from work due to illness, sick days, or other personal reasons. These days will be deemed to be earned and accrue on a monthly basis and which will not be paid for in advance. You may not accrue more than your applicable maximum allotment of PTO days.

This offer is contingent on your execution and delivery to us of (i) this agreement, and (ii) the Company’s Non-Disclosure and Developments Agreement attached hereto, and (iii) the Employee Non-Solicitation and Non-Competition Agreement attached hereto by November 7, 2005 at 5:00 p.m., after which time this offer will terminate if not accepted. The execution of each of the above referenced documents is a condition of your employment.

Please note that your written acceptance of this offer also confirms your understanding and agreement that your employment with the Company is “at-will,” meaning that either you or the Company may terminate your employment at any time and for any reason. You further acknowledge that this letter does not constitute an employment contract.

If you are not a US Citizen it may be necessary for you to obtain a work permit or Visa from the U.S. Department of Homeland Security. If this is the case, the company will engage Immigration Attorneys and will make every reasonable effort to obtain the necessary authorizations for you to work in the U.S. If such a Work Permit, or Visa, is required, then it will become a condition of your employment and your employment will terminate if you are denied permission to work in the U.S.

We are tremendously excited about the opportunity for you to join our team. Please feel free to contact me if you need any further information prior to the deadline indicated above.

/s/ Jeffrey G. Barnett

Accepted this      day of         , 2005

Subject: 2010 Performance Bonus

Your bonus opportunity for 2010 is $25,000. This is funded based upon company financial performance as follows:

The funding of this bonus does not guarantee that you will receive a bonus. In order to achieve any of this potential bonus, you must meet your individual objectives and be an employee at the time the bonus is paid. Your individual objectives and the portion of the bonus earned upon achievement are as follows:

Individual Objectives for 1H 2010

In each case, we will assess the achievement of the objective as Excellent, Good, Satisfactory or Unsatisfactory. You will earn full value for Excellent, 90% for Good, 75% for Satisfactory or 0% for Unsatisfactory.

Bonuses will be distributed in February 2011

Sincerely,

/s/ Thomas D. Ebling                            /s/ JB

Thomas Ebling

CEO

Demandware

2010 Compensation Plan and Sales Commission Structure (the”Plan”)

Jeff Barnett, Executive Vice President Field Operations (the “VP”)

Quota:

VP’s 2010 sales quota is ACV billings of $8,504,853.

Base Salary:

VP’s base salary is $175,000.

Commission Plan:

Commissions will be awarded based on committed, signed contracts. The commission rates for 2010 Quota and above are as follows:

Notes:

I acknowledge and accept the terms and conditions of this compensation plan.

Demandware

2011 Compensation Plan and Sales Commission Structure (the”Plan”)

Jeff Barnett, Executive Vice President Field Operations (the “VP”)

Quota:

VP’s 2011 sales quota is ACV bookings of $12,786,400.

Base Salary:

VP’s base salary is $190,000.

MBO Bonus:

Annual MBO bonus opportunity is $50,000 based on the corporate incentive pool and is evaluated against the following MBO’s:

Commission Plan:

Annual commission opportunity is $100,000. Commissions will be awarded based on committed, signed contracts. The commission rates for 2010 Quota and above are as follows:

Notes:

I acknowledge and accept the terms and conditions of this compensation plan.