1. Introduction

These Terms and Conditions ("Terms") govern the services ("Services") provided by Stackable, a brand of Christian Meckelburg, with business address at Kolonnenstraße 8, 10827 Berlin, Germany (”Stackable”), to you ("Client").

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By engaging with our Services, you agree to these Terms. By ordering a Service, signing a proposal, or otherwise indicating acceptance in writing or electronically, such as by making a payment, the Client agrees to these Terms. These Terms apply exclusively to entrepreneurs (Unternehmer, § 14 BGB), legal entities under public law, or special funds under public law. Stackable does not contract with consumers (Verbraucher, § 13 BGB) under these Terms.

2. Services

All Services provided by Stackable under these Terms are outcome-based and constitute a 'Werkvertrag' (contract for work and services) under German law, obliging Stackable to produce the agreed-upon work/deliverable ('Werk').

2.1 Service Types

We offer the following types of Services:

1. Defined Package: Stackable provides a defined set of deliverables and outcomes as a 'Defined Package', the specifics of which are outlined on Stackable’s website. A contract for a Defined Package is concluded upon the Client's order (e.g., via the website, email or payment) and Stackable's acceptance (e.g., by order confirmation or commencement of Service). The specific scope, deliverables (Werk), content, and pricing of the Defined Package are detailed on Stackable's website at the time of order and form an integral part of the contract.
2. Bespoke Projects: For custom requirements, we offer bespoke projects with detailed written agreements covering scope, deliverables (Werk), and timelines. For Bespoke Projects, a separate written offer and acceptance (hereinafter 'Project Agreement') detailing the scope, deliverables, timelines, and remuneration will be concluded. These Terms shall form an integral part of such Project Agreement, prevailing unless explicitly agreed otherwise in writing in the specific Project Agreement.

Remote & Async Delivery: Unless otherwise agreed in the Project Agreement, all Services are performed remotely. Should on-site services at a location specified by the Client be agreed upon, the Client shall bear pre-approved travel costs and expenses.

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Modifications and Updates: Stackable reserves the right to modify its general service offerings and their descriptions for future engagements. Modifications to the scope, terms, or pricing of already concluded contracts require a mutual agreement in text form (Textform, e.g. email).

2.2 Revisions

Requests for changes or additions by the Client that extend beyond the originally agreed scope of Services or the included revision rounds ('Change Requests') are not covered by the agreed remuneration. Stackable will, if feasible, provide a separate offer for such Change Requests. Stackable will inform the Client of any potential additional costs resulting from Change Requests and obtain the Client's approval before commencing such additional work.

2.3 Client Cooperation

The Client agrees to provide all necessary materials, information, and access required for Stackable to perform the Services. Delays caused by the Client's failure to provide such cooperation may impact timelines and are not the responsibility of Stackable. The Client is responsible for the accuracy, completeness, and legality of all materials, information, and access provided. Stackable is not obliged to verify these for accuracy or legal compliance unless this is an explicit part of the agreed Services. If the Client fails to provide necessary cooperation in a timely manner despite a reminder from Stackable setting a reasonable grace period, Stackable may be entitled to adjust timelines, claim additional expenses incurred due to the delay, or, in case of significant or persistent breach, terminate the contract according to clause 5.

2.4 Subcontractors

Stackable reserves the right to engage third-party subcontractors to assist in providing the Services, where necessary. Stackable remains fully responsible to the Client for the performance of Services rendered by its subcontractors as if performed by Stackable itself, unless otherwise stipulated by mandatory law.

2.5 Delivery Deadlines

Agreed delivery deadlines are estimates unless explicitly designated as binding ('verbindlich') in writing by both parties. Deadlines shall be reasonably extended if delays are due to circumstances outside Stackable's reasonable control, including but not limited to Client's failure to meet cooperation duties or force majeure events.

3. Payment Terms

3.1 Remuneration, Upfront Payment, and Acceptance

The remuneration for the Services is specified in the Defined Package description on the website or in the individual Project Agreement. All prices are net prices and are subject to statutory VAT. Unless otherwise explicitly agreed in writing in a Project Agreement (e.g., milestone payments for Bespoke Projects), the full remuneration for the agreed Services (Werk) is due as an upfront payment upon conclusion of the contract. Stackable is not obliged to commence performance of the Services until full payment has been received. Upon completion of the agreed work/deliverables (Werk), Stackable will notify the Client of its completion and, where applicable, provide the work for inspection and acceptance. The Client is obliged to accept the contractually produced work (Abnahme gemäß § 640 BGB) if it is free from material defects.

Acceptance shall be deemed to have occurred if the Client does not refuse acceptance in writing, stating at least one material defect, within ten (10) working days of notification of completion and opportunity for inspection. Minor defects do not entitle the Client to refuse acceptance but shall be remedied by Stackable under its warranty obligations. The productive use or deployment of the work or parts thereof by the Client shall also constitute acceptance. If partial deliveries or milestones have been agreed and accepted, corresponding partial payments as per the Project Agreement become due upon acceptance of each partial delivery/milestone.

3.2 Invoicing

Invoices for upfront payments are issued upon conclusion of the contract and are payable immediately, unless a different payment term (e.g., 14 days) is stated on the invoice or agreed in writing. For any other payments agreed (e.g., for Change Requests, subsequent milestones not covered by upfront payment), invoices are payable within 14 days of the invoice date, unless otherwise agreed in writing. All amounts are exclusive of statutory VAT. In case of late payment, Stackable is entitled to charge statutory default interest (currently 9 percentage points above the base rate for B2B transactions) from the due date. The right to claim further damages for delay remains unaffected.

3.3 Interim Billing

If the Client's lack of cooperation (as per clause 2.3), despite a reminder and setting of a reasonable grace period by Stackable, significantly delays or interrupts the project, Stackable is entitled to invoice for all Services performed up to that point. Further claims for compensation (e.g., for idle time or additional expenses due to the Client's breach) according to statutory law remain unaffected.

3.4 Warranty for Defects

Stackable warrants that the delivered work (Werk) corresponds to the agreed specifications and is free from defects that would nullify or materially diminish its value or fitness for the contractually intended use.  The Client shall inspect the work upon delivery/notification of completion and notify Stackable in text form of any apparent defects without undue delay, but no later than ten (10) working days after delivery or acceptance. Hidden defects must be notified in text form without undue delay after their discovery. Failure to provide timely notice of defects may affect the Client's warranty rights to the extent permitted by law.

In the event of a defect for which Stackable is responsible, the Client is entitled to statutory warranty rights, primarily the right to subsequent performance (Nacherfüllung). Stackable may, at its discretion, remedy the defect by repair (Nachbesserung) or by delivering a new, defect-free work (Neulieferung). The Client must grant Stackable a reasonable period for such subsequent performance. If subsequent performance fails (e.g., if it is impossible, unreasonable, refused by Stackable, or after two unsuccessful attempts), or if it is not reasonable for the Client, the Client may, in accordance with statutory provisions: i. Reduce the remuneration (Minderung); ii. Terminate the contract (Rücktritt), unless the defect is insignificant; and/or iii. Claim damages or reimbursement of futile expenses, subject to the limitations of liability set forth in Section 8. The warranty period (Verjährungsfrist für Mängelansprüche) is twelve (12) months from acceptance of the work, unless mandatory statutory provisions provide for a longer period or unless liability is unlimited under Section 8.1 a). This limitation does not apply to claims for damages arising from injury to life, body, or health due to a negligent breach of duty by Stackable or an intentional or negligent breach of duty by a legal representative or vicarious agent of Stackable.

4. Intellectual Property

4.1 Intellectual Property Rights

All materials, information, and content, including but not limited to text, graphics, logos, images, and other materials used or delivered by Stackable, are the property of Stackable or its clients and are protected under applicable copyright, trademark, and other intellectual property laws.

4.2 Ownership of Materials

Upon full and final payment of all remuneration due for the specific Service, Stackable grants the Client non-exclusive, perpetual, worldwide, irrevocable rights of use (Nutzungsrechte) to the copyrightable work results specifically created by Stackable for the Client as part of the deliverables under that Service (hereinafter 'Client Deliverables'), solely for the Client's internal business purposes directly related to the subject matter of the Service. The Client may only transfer or sublicense these rights with Stackable's prior written consent. Any grant of exclusive rights to any part of the Client Deliverables requires an explicit written agreement to that effect in the Project Agreement and may be subject to additional remuneration.

Notwithstanding any grant of rights to the Client, Stackable retains all intellectual property rights, title, and interest in and to: a) its pre-existing materials, methodologies, know-how, generic code, tools, and preparatory works developed or used by Stackable in providing the Services ('Stackable's Background IP'); and b) any improvements, modifications, or derivative works of Stackable's Background IP, even if developed in the course of providing the Services. Stackable explicitly retains the right to use the general skills, know-how, concepts, and experience, as well as any non-client-specific and anonymized elements from the Client Deliverables, gained during the performance of the Services for any purpose, including for providing services to other clients, provided that Stackable does not thereby infringe upon any exclusive rights specifically granted to the Client or disclose the Client's Confidential Information. In case of doubt regarding the scope of rights granted, the scope is limited to what is necessary to achieve the purpose of the contract (Zweckübertragungstheorie). Stackable retains the right to showcase the work (Client Deliverables) in its portfolio and marketing materials, unless otherwise restricted by a Non-Disclosure Agreement (NDA) or explicitly agreed otherwise in writing.

4.3 Client's Materials

By providing content or materials, the Client warrants that they have the necessary rights and that such content does not infringe on any third-party intellectual property rights. The Client warrants that it holds all necessary rights to the materials provided to Stackable and that such materials do not infringe any third-party rights. The Client shall indemnify, defend, and hold harmless Stackable from and against all claims, damages, losses, liabilities, costs, and expenses (including reasonable attorneys' fees) arising from any third-party claim that the materials provided by the Client infringe third-party intellectual property rights or other laws.

5. Termination and Refund

5.1 Termination by Client

The Client may terminate the agreement by providing notice in text form (Textform, e.g., email). Upon receipt of the termination notice, the following terms apply based on the type of service and the payment status:

• If Payment Was Made Upfront: If the Client terminates the contract before completion of the work (freie Kündigung gemäß § 648 BGB), Stackable is entitled to the agreed remuneration for the entire project. However, Stackable must deduct any expenses saved due to the termination, as well as any revenue generated from alternative use of its labor capacity, or revenue maliciously omitted. Any upfront payment exceeding this total amount will be refunded.
• If Payment Is Outstanding: If the Client terminates the contract without cause before completion of the work (freie Kündigung gemäß § 648 BGB), Stackable is entitled to payment for all work performed up to the effective date of termination. For the unperformed part of the Services, Stackable shall be entitled to 10% of the net remuneration attributable to this unperformed part as liquidated damages (pauschalierter Schadensersatz) for lost profit and administrative overhead, unless the Client proves that Stackable incurred no damage or significantly less damage than this flat rate. Stackable reserves the right to prove and claim higher actual damages (i.e., the full remuneration less actual saved expenses and alternative earnings as per § 648 Satz 2 BGB) if these exceed the flat rate. This does not apply if the Client terminates for cause attributable to Stackable.‍

5.2 Termination by Stackable

Stackable may terminate this agreement only for material cause (aus wichtigem Grund) in accordance with statutory provisions (e.g., § 643 BGB in conjunction with § 314 BGB if the Client fails to fulfill an act of cooperation incumbent upon them and fails to do so within a reasonable grace period set by Stackable, or if continuation of the contract becomes unreasonable for Stackable). A material cause also includes, but is not limited to: a) a significant breach by the Client of its contractual obligations (e.g., persistent failure to meet essential cooperation duties despite reminders, making performance impossible or unreasonable for Stackable); b) if insolvency proceedings are initiated against the Client's assets. Where legally required (e.g., for breaches of duty that are in principle remediable), Stackable will issue a written warning (Abmahnung) setting a reasonable cure period before terminating for cause, unless specific circumstances (e.g., severity of breach, § 323 Abs. 2 BGB) render a warning futile or unreasonable. In the event of termination by Stackable for cause attributable to the Client, Stackable is entitled to remuneration for Services performed up to the termination date, plus any applicable claims for damages. If Stackable terminates for reasons not attributable to the Client, any prepaid fees for unperformed Services will be refunded on a pro-rata basis.

6. Confidentiality and Publication

6.1 Confidentiality

Both parties agree to maintain the mutual confidentiality of all information that is identified as confidential or whose confidential nature is evident from the circumstances of disclosure. Such information shall not be disclosed to third parties without prior written consent from the disclosing party. This obligation of confidentiality shall survive the termination or expiration of this agreement for a period of 3 years. The obligation to maintain confidentiality does not apply to information that:

• Was known to the receiving party prior to the disclosure date;
• Became publicly available prior to or after the disclosure date without fault of the receiving party;
• Was independently developed by the receiving party without use of or reference to the disclosing party's confidential information.

6.2 Publication Rights

Stackable may refer to the Client as a reference client on its website and in other formats. This right remains in effect indefinitely beyond the termination of the contract. Stackable may also publicly display the work results (excluding confidential or personal data) and use the Client's logo for demonstration purposes, unless the Client objects in writing.

7. Data Protection

a) Both Stackable and the Client shall comply with all applicable data protection regulations, including the General Data Protection Regulation (GDPR) and the German Federal Data Protection Act (BDSG), in handling any personal data.

b) Stackable processes personal data of the Client's business contact persons (e.g., names, email addresses, phone numbers of Client employees involved in the project) for the purposes of contract execution, communication, and administration, as further detailed in Stackable's Privacy Policy available at https://www.stackablerev.com/privacy. Stackable is the data controller for this processing.

c) The Client expressly warrants and undertakes that it shall not provide, upload, transfer, or otherwise make accessible to Stackable any personal data of its own customers, users, employees (other than the Client's business contact persons specified in 7.b), or any other third parties for processing by Stackable in the course of the Services, where such provision would render Stackable a data processor (Auftragsverarbeiter) on behalf of the Client under Art. 4 No. 8 GDPR.

d) The Client is solely responsible for ensuring that any data, materials, or information provided to Stackable for the performance of the Services are either free of personal data or have been fully and irreversibly anonymized such that they no longer constitute personal data under the GDPR. If pseudonymized data is provided, the Client warrants that Stackable will have no means to re-identify individuals.

e) Should the Client, contrary to its obligations under Section 7.c) and 7.d), provide personal data to Stackable which results in Stackable being deemed a data processor, the Client shall:

i.  Immediately inform Stackable thereof;

ii. Be solely responsible for the lawfulness of such processing and for ensuring compliance with all applicable data protection laws, including the conclusion of a Data Processing Agreement (DPA/AVV) with Stackable if deemed necessary by Stackable or required by law, the terms of which Stackable may define; and

iii. Indemnify, defend, and hold harmless Stackable from and against any and all third-party claims, regulatory fines, damages, losses, liabilities, costs, and expenses (including reasonable attorneys' fees) arising out of or relating to the Client's breach of this Section 7.

f) Stackable reserves the right to refuse, cease processing, delete, or return any data provided in breach of this Section 7, or to charge the Client for any additional work or costs incurred in handling such data or in establishing necessary compliance measures (such as a DPA/AVV if Stackable, at its sole discretion, agrees to act as a processor).

8. Limitation of Liability

8.1 General Liability

Stackable's liability shall be governed by the following provisions: a) Stackable shall be liable without limitation for damages caused by intentional misconduct (Vorsatz) or gross negligence (grobe Fahrlässigkeit) by Stackable, its legal representatives, or executive employees; or for damages arising from culpable injury to life, body, or health. b) For damages caused by ordinary negligence (einfache Fahrlässigkeit) by Stackable, its legal representatives, or vicarious agents (Erfüllungsgehilfen), Stackable shall only be liable if an essential contractual obligation (wesentliche Vertragspflicht or Kardinalpflicht) is breached. Essential contractual obligations are those whose fulfillment is a prerequisite for the proper execution of the contract and on whose observance the Client regularly relies and may rely. c) In the event of a breach of an essential contractual obligation due to ordinary negligence (as per 8.1 b)), Stackable's liability shall be limited to the foreseeable damage typical for this type of contract (vertragstypischer, vorhersehbarer Schaden). d) Any further liability of Stackable for ordinary negligence is excluded. e) The limitation periods for claims for damages, including warranty claims (Mängelansprüche as per Section 3.4), shall be governed by statutory law, except where expressly modified in these Terms (e.g., Section 3.4 e) for warranty claims).

8.2 Third-Party Service Providers

Stackable is not liable for the services, functionality, compatibility, failures or compatibility with Stackable’s work of third-party services, software, or hardware engaged or used directly by the Client and not forming part of Stackable’s agreed deliverables. Stackable is not obligated to support these third-party service providers.

8.3 Legal Compliance

The Services do not include legal advice. The Client is solely responsible for the legal compliance of its business operations, projects, content, and use of Stackable's deliverables. The Client shall indemnify Stackable against any third-party claims (including legal costs) asserted against Stackable arising from the Client's alleged or actual infringement of laws or third-party rights in connection with the subject matter of this agreement, unless Stackable is demonstrably responsible for such infringement.

8.4 Exclusion of Liability

Under no circumstances is Stackable liable for loss of data, revenue, profit, or any interest and downtime costs that arise as a result of a non-negligent action by Stackable. Stackable's liability for loss of data due to ordinary negligence is limited to the typical recovery costs that would have been incurred if the Client had performed regular and adequate data backups appropriate to the risk and value of the data.

8.5 Choice of Law and Jurisdiction

This agreement and all legal relationships between Stackable and the Client arising out of or in connection with the Services shall be governed exclusively by the laws of the Federal Republic of Germany, to the exclusion of its conflict of laws principles and the UN Convention on Contracts for the International Sale of Goods (CISG).

The exclusive place of jurisdiction for all disputes arising from or in connection with this agreement shall be Berlin, Germany, provided the Client is a merchant (Kaufmann), a legal entity under public law, or a special fund under public law.

8.6 Amendments and Written Form

Amendments, supplements, and the termination of this agreement or these Terms must be in text form (Textform, e.g., email) to be effective, unless a stricter form (e.g., written form with handwritten signature) is required by law or explicitly agreed herein. This also applies to any waiver of this text form requirement. Individual agreements (Individualabreden) always take precedence over these Terms.

8.7 Severability Clause

Should any provision of these Terms be or become invalid, illegal, or unenforceable in whole or in part, the validity, legality, and enforceability of the remaining provisions shall not be affected thereby. In place of the invalid, illegal, or unenforceable provision, the parties shall agree on a valid, legal, and enforceable provision that comes as close as possible to the economic purpose and intent of the original provision. The same shall apply mutatis mutandis to any unintended gap or omission in these Terms.

8.8 Entire Agreement

These Terms, together with any applicable Project Agreement or confirmed offer, constitute the entire agreement between Stackable and the Client with respect to the subject matter hereof and supersede all prior oral or written communications, understandings, proposals, and representations.