Design Sparring
From solo problem to live product: a practice tool that argues back, so a design decision is tested before the room tests it.
Design Sparring is a practice tool for designers and product professionals who make decisions under pressure and defend them to stakeholders. It launched with a single tool, a structured three-round argument engine with a scored verdict, and has since expanded to a Stakeholder Simulator, a decision-style quiz, and an affiliate programme for design education partners.
- My role
- Solo: strategy, product, UX/UI design, full-stack engineering, prompt engineering, copy, CRO, marketing, legal pages, and growth
- Timeline
- 2025 to 2026, still shipping
- Toolkit
- Next.js 14 App Router
- Vercel
- Neon Postgres
- Magic link auth
- Upstash Redis
- Stripe
- Resend
- Claude API
- Vercel Analytics
Product strategy was built around one bet: reduce friction before asking for value. Removing the account gate from the free tier was the highest-leverage decision. In comparable design-tool funnels, forced signup before first use can drop activation by 25-40%, so the first round stays open, no email required. The paywall appears after round one, when the user has felt the counter-argument but has not yet reached a verdict. Pricing was split into two standalone subscriptions, $9 for Sparring Partner and $12 for Stakeholder Simulator, rather than bundling into a single $18-21 plan. This keeps each tool positioned as complete on its own and preserves clean retention signals. Magic-link auth removes password-reset support overhead, and 30-day session history keeps the product useful while limiting data liability.
Better decisions come from being questioned, not agreed with.
Design Sparring is a smart practice tool for designers and product professionals who make decisions under pressure and defend them to stakeholders. It stress-tests your rationale, not your feelings, before the real meeting happens.
The product launched with a single tool: a structured three-round argument engine that counters your design decision and delivers a scored verdict. It has since expanded to include a Stakeholder Simulator, a decision-style assessment quiz, and an affiliate programme for design education partners.
- Sparring Partner
- $9/mo
- Stakeholder Simulator
- $12/mo
- No account required
- Free
- Built solo
- 100%
Sparring Partner
Stakeholder Simulator
No account required
Built solo
Designers work alone. Decisions go unchallenged.
This product started from a personal professional reality: working solo, or as the only designer in a team, means there is nobody to push back on your thinking before it reaches a client or a stakeholder meeting. Feedback tools exist. Critique exists. But critique is commentary, it suggests alternatives. What was missing was something that would argue the other side of a decision, force a defense, and expose the weak points in the reasoning before anyone else did.
Better decisions come from being questioned, not agreed with.
The gap is not skill, it is the absence of structured adversarial pressure. A designer who has never had to defend a decision under pushback has not tested whether they truly believe it, or simply have not been challenged yet. The difference only becomes visible in the room, in front of a CPO who does not agree, or a client who needs convincing.
Design Sparring was built to make that pressure available on demand, privately, repeatedly, and without the social cost of being wrong in public.
Two tools. One premise.
The product is built around a single belief: that the ability to defend a decision is as important as the ability to make one. Every feature follows from that.
Sparring Partner
The core product. The user pastes a design rationale, any decision, any level of seniority, and receives a structured counter-argument. Three rounds, each escalating in specificity. At the end, a scored verdict across four dimensions: Clarity, User Impact, Defensibility, and Blind Spots. Not encouragement. Not suggestions. A fight.
The history of your sparring sessions is yours to download and look over at any time.
Stakeholder Simulator
The second product, designed after the core tool proved its premise. Where the Sparring tool tests the logic of a decision, the Simulator tests the designer's ability to handle a specific kind of human opposition: the stakeholder who has power, an agenda, and no obligation to agree with you.
Seven archetypes, Risk-averse CPO, Impatient Founder, Skeptical Engineer, Budget CFO, Confused End User, Compliance Officer, and Sales Lead, each with a documented concern character. The session then generates a downloadable prep sheet: objections raised, strongest and weakest responses, and the three questions that stakeholder will most likely ask in the real meeting.
Why not just use ChatGPT?
ChatGPT returns prose. Design Sparring returns a structured format: Concern / Implication / What they will say. It maintains character consistency across all three rounds. It produces a branded deliverable, the prep sheet, that the designer can take into the room. A chatbot gives a conversation. This gives a tool.
0 to 1, solo.
Every part of this product was built by one person. There was no team, no agency, no co-founder. The scope covered the full product lifecycle.
Strategy & product
- Problem definition and market positioning
- Pricing model design, two independent subscriptions at $9 and $12
- Free tier architecture, conversion optimised, no account required
- Affiliate and partnership programme design
- Business model including API cost analysis and margin modelling
Design & engineering
- Full UX/UI design, brand system, component library, interaction design
- Next.js 14 App Router, full-stack development
- Stripe integration, live payments, webhooks, subscription management
- Anthropic Claude API, prompt engineering for both products
- Auth, session history, PDF generation, rate limiting, analytics
Copy & content
- All product copy, landing page, modals, emails, legal pages
- FAQ, privacy policy, terms of service, cookie policy
- LinkedIn content strategy and post writing
- Partnership proposal and affiliate agreement documents
Marketing & growth
- SEO, sitemap, robots.txt, OG image, meta
- LinkedIn Insight Tag and Vercel Analytics integration
- Affiliate tracking system, referral attribution, commissions, partner dashboards
- Outreach strategy for design bootcamp partnerships
Every decision was deliberate.
Free tier with no account required
The single most important conversion decision on the product. Both tools offer a free tier, one round, no email, no signup. The biggest barrier to trying a new tool is not price, it is friction. Requiring an account before the user has experienced the product filters out the people most likely to become paying users, the ones who are genuinely curious but not yet convinced. By removing the signup gate from the first experience, the product earns trust before asking for anything. The conversion moment comes after the first round, when the user has felt the value and wants more. At that point, they are already believers, not sceptics.
Two independent subscriptions, not a bundle
Sparring Partner at $9/mo and Stakeholder Simulator at $12/mo are deliberately separate. This was not a pricing trick, it was a product positioning decision. Bundling would have made the Simulator feel like an add-on or a feature. Keeping them independent signals that each is a complete, standalone product with its own value proposition. A designer who only needs to stress-test their rationale does not need the Simulator. A PM who only needs to rehearse stakeholder conversations does not need the Sparring tool.
Magic link authentication
No passwords. Users sign in with a one-time link sent to their email address. This decision was driven by simplicity and trust, there is no password to forget, no reset flow to build, and no stored credential to breach. For a product that asks users to paste sensitive design decisions and business context, reducing the surface area for security issues is a product value, not just a technical choice.
The scored verdict
The sparring tool does not end with a suggestion or a summary. It ends with a score across four dimensions. The point of the tool is to give the user something concrete to act on, not a feeling. A score externalises the assessment, making it easier to share, discuss, and return to. It also creates a baseline, something the user can try to improve in the next session.
Session history for 30 days only
Session history is retained for 30 days, then permanently deleted. This was both a product decision and a privacy decision. Permanently storing design decisions, business rationale, and strategic thinking creates a data liability, especially for users working under NDA or in sensitive industries. Thirty days is long enough for the history to be useful, review before a follow-up meeting, download a PDF for reference, without creating a permanent record of sensitive content. The deletion is automated and unconditional.
Separate pricing for the Simulator from day one
The internal product brief modelled multiple options: bundle the Simulator into the existing $9/mo tier, offer it as an add-on at $15 to $18/mo combined, or launch it as a standalone product. The standalone approach was chosen to test market fit independently, avoid diluting the perceived value of either product, and maintain a clean signal for which tool drives retention. If session data shows the Simulator has higher engagement and retention than the core tool, pricing can move accordingly. Launching bundled removes that optionality.
The landing page was designed to convert, not impress.
Every structural decision on the landing page was made in service of one outcome: getting a first-time visitor to start a free session. The sequence of elements was designed to move someone from skepticism to action without friction.
Hero, specificity over cleverness
"Paste your design rationale. Get a structured counter-argument. Three rounds. A scored verdict. No encouragement." The headline does not use metaphor or aspiration. It describes what happens when you use the product, in the exact order it happens. Designers are trained to distrust vague claims and respond to specificity. The copy treats them accordingly.
Live demo carousel above the fold
The hero section includes a rotating demo carousel showing real sparring and simulation exchanges, not marketing copy, not mockups. Visitors see the actual output before they interact with anything. This reduces the "is this real?" question that most tools trigger. The carousel alternates between Sparring and Simulator cards, giving both products exposure without requiring the visitor to navigate anywhere.
Free tier positioned as the primary CTA
"Start sparring free" is the primary button. Not "Sign up" or "Try for free", both of which imply friction. The CTA is a description of the action, not a commitment. Below it: "Free tier, no account required." This single line removes the two most common reasons people do not click a CTA: they do not want to give their email, and they do not want to be sold to.
The paywall after round 1
Free users get one round. This is not a limitation, it is a conversion mechanism. One round is enough to experience the value of the tool. It is not enough to feel satisfied. The second round is harder, the third harder still. Stopping at round 1 leaves the user at the moment of maximum curiosity, with a blurred preview of the next counter-argument visible below the paywall. The upgrade prompt appears at exactly the moment the user wants more.
Audience segmentation tabs
The landing page includes a tab-based section that addresses five distinct audiences: Senior Designers, Freelancers, Product Managers, Junior Designers, and Founders. Each tab shows a different hook and body copy tailored to that audience. A single generic message converts worse than a targeted one. Rather than building five separate landing pages, the tab system lets each visitor self-select into the message most relevant to them, without a separate URL or campaign.
Pricing transparency
Both subscription prices are visible on the landing page. No "contact us for pricing", no trial-first gate. Hiding pricing suggests the product is expensive or that the company does not trust the visitor to make a decision. Showing $9 and $12 upfront removes a common abandonment trigger and lets the user evaluate the product on its merits.
The quiz nobody expected to be useful.
The "What is your design decision style?" quiz was added to the navigation bar as a self-contained, free, no-account tool. On the surface it looks like a piece of engagement content, the kind of thing you share on LinkedIn after taking it. Strategically, it serves four distinct purposes.
1. Top-of-funnel acquisition
The quiz reaches people who are not yet ready to use the sparring tool. They may not have a decision to defend right now, or may not yet understand what the product does. The quiz gives them a reason to engage without requiring any of that context. It is the lowest-friction entry point in the product.
2. Self-identification
The quiz result tells the user something true about themselves. This is the mechanic that drives sharing. People share assessments not because they are fun, but because the result reflects their identity in a way they want others to see. Every share is a referral.
3. Product framing
The result is followed by a contextual explanation of how that decision style interacts with pressure and pushback, and a natural prompt to test their decisions with the sparring tool. The quiz does not advertise the product. It creates the context in which the product becomes the obvious next step.
4. Email capture, optional
At the end of the quiz, users can optionally receive their results by email. This is not a gate, the results are shown on screen regardless. Users who want a record of their result provide their email, creating a permission-based contact. No spam, no nurture sequence, just the result they asked for.
Building a distribution channel, not just a product.
Design Sparring operates an affiliate programme specifically targeting design bootcamps, UX programmes, and design education communities. The rationale: design education is where designers are most actively trying to improve, and where the pain point the product addresses, defending decisions and handling stakeholder pushback, is most acutely felt and least well served.
How it works
Each partner receives a unique referral link. When a student subscribes through that link, the partner earns a commission on the first month, $1.80 per Sparring Partner subscription and $2.40 per Stakeholder Simulator subscription, 20% of the first month. Partners get a private, live dashboard showing their signups, conversions, and earnings in real time. No monthly reports, no back-and-forth.
Why bootcamps specifically
Bootcamp students are designers at the exact moment of maximum motivation and maximum vulnerability. They are actively looking for tools to make them better, and they are about to enter a job market where defending design decisions in front of stakeholders is a primary professional challenge. The affiliate programme reaches this audience through the educators they already trust, rather than through paid advertising they will ignore.
- A unique tracked referral link with 30-day attribution
- A live, password-protected dashboard with real-time commission tracking
- Website listing, logo, name, and link, from the first converted student
- Complimentary full access for up to two instructors
- Commission paid by the 10th of the following month
The programme was designed to be self-sufficient: partners have everything they need to run the referral independently, without ongoing support or manual reporting from the product side. The live dashboard is not a convenience feature, it is a trust mechanism. Partners who can see their impact in real time are partners who continue to promote. Opaque monthly reports create doubt. Transparent live data creates advocates.
Built to be lean, not to be impressive.
Every technology choice was made to minimise overhead, maximise delivery speed, and keep the product maintainable by one person. There is no unnecessary complexity.
- Frontend & routing
- Next.js 14 App Router, React server and client components
- Hosting
- Vercel, serverless functions, edge network, automatic deploys from GitHub
- Database
- Neon Postgres, session history, user accounts, affiliate tracking
- Auth
- Magic link, JWT session tokens, Upstash Redis for token storage
- Payments
- Stripe, live subscriptions, webhooks, billing portal
- Resend, transactional email for auth, payments, and account events
- AI
- Anthropic Claude API, sparring counter-arguments, stakeholder objections, verdicts
- Rate limiting
- Upstash Redis, free-tier session limits by hashed IP
- Analytics
- Vercel Analytics plus anonymous usage logging, hashed IP, no PII
What building this taught me.
Building Design Sparring end to end, strategy, product, design, engineering, copy, marketing, legal, and growth, surfaced a set of lessons that no individual workstream would have produced on its own.
Friction is the product
Removing the signup gate from the free tier felt like a risk, it means some users will use the tool without ever converting. In practice, removing friction from the first experience is what creates trust, and trust is what drives conversion. The users who convert to paid have already experienced the value. They are not being sold to, they are buying access to more of something they already know works.
A scored verdict changes the relationship with feedback
Early versions returned prose summaries. The scored verdict, four dimensions each rated, changed how users related to the output. Prose is arguable. A score is concrete. Users who receive a 2 out of 5 on Defensibility do not argue with the framing, they ask what they can do about it. That shift from passive reader to active improver was the moment the product became genuinely useful rather than merely interesting.
Solo is not a constraint, it is a filter
Building this alone meant every decision had to be worth making. There was no team to absorb bad decisions, no process to catch unnecessary complexity, no budget to recover from a wrong turn. That constraint produced a leaner product than any team process would have. Every feature that exists is there because it earns its place.
The absence of pushback is not validation. It is silence.