The single biggest predictor of whether a Shopify custom development project runs smoothly isn’t the developer’s skill level, it’s the quality of the brief they were given. A vague brief (“we want a better product page” or “make checkout more like the big brands”) forces the developer to guess, and guesses get built, priced, and then reworked once you see it and realise it’s not what you meant. That rework isn’t free, and on a fixed-quote project, it’s usually the merchant who ends up paying for the gap between what was asked for and what was actually needed.
This isn’t about writing a 40-page specification document. Most merchants don’t need that, and most good developers don’t want it, over-specification can be just as unhelpful as under-specification, because it locks in decisions that should really be left to someone with more technical context. What actually matters is covering the handful of things that, if left unsaid, reliably cause scope disputes later. This post covers exactly those.
Why vague briefs cost more than they save
A brief like “we want a mega menu like [competitor]” tells a developer what the end state should look like on the surface, but not:
- Whether it needs to be driven by collections, manually curated links, or a mix of both
- Whether it needs to work identically on mobile (a full mega menu rarely translates directly to mobile navigation)
- Whether images/icons per category are required, and who’s providing them
- Whether it needs to support the number of top-level categories you actually have, or just the four visible in the competitor’s screenshot
Every one of those gaps becomes a decision the developer makes on your behalf, based on a guess. If the guess is wrong, you’re now paying for a second round of work that a five-minute clarifying conversation upfront would have avoided entirely.
What a good Shopify development brief actually needs
1. The problem, not just the feature request
Start with what’s actually not working, not just the solution you’ve landed on. “Customers can’t tell which products are in stock in their size before adding to cart, and we’re getting refund requests over it” gives a developer far more to work with than “add a stock indicator,” because it lets them flag if there’s a better native or lower-cost way to solve the actual problem you’re describing.
2. Exact current behaviour vs desired behaviour
Describe what happens today, step by step, and what should happen instead. Screenshots or a short screen recording are genuinely more useful here than paragraphs of description, ambiguity in written descriptions of UI behaviour is one of the most common sources of “that’s not what I meant.”
3. Scope boundaries, what’s explicitly not included
This is the most commonly skipped part of a brief, and the one that prevents the most disputes. If you want a size guide added to product pages, say explicitly whether that includes: every product, or just apparel; a static chart, or one that varies by product type; and whether it needs a translated/localised version. Developers will make reasonable assumptions about anything you leave open, but “reasonable” from their side and “obvious” from yours aren’t always the same thing.
4. Which Shopify plan and theme you’re on
Shopify Plus unlocks capabilities (Shopify Functions, checkout customisation, more script/API headroom) that standard Shopify doesn’t, and theme architecture varies enormously between Dawn-based themes, older Vintage themes, and heavily customised or headless setups. A brief that doesn’t mention this forces the developer to ask before they can even estimate, better to state it upfront.
5. Existing apps and integrations that touch the affected area
If the feature you’re briefing touches a page or flow that an app already customises (a reviews app injecting content into the product page, a subscription app altering the buy box, a personalisation app rewriting product recommendations), say so. Conflicts between custom code and existing apps are one of the most common sources of unexpected rework, and they’re avoidable if flagged at brief stage rather than discovered during QA.
6. Design assets and who owns design decisions
Be explicit about whether you’re providing finished designs (Figma, mockups), rough references (screenshots of things you like), or expecting the developer to make design decisions within your existing brand guidelines. All three are legitimate starting points, but mixing them up mid-project, expecting pixel-perfect execution when you only gave a rough reference, is a common source of friction.
7. Success criteria you can actually check
“Make it faster” isn’t testable. “Product pages should load in under X seconds on mobile per PageSpeed Insights” is. Not every brief needs a hard metric, but for anything performance-, conversion-, or SEO-related, define what “done and working” looks like before development starts, so there’s a shared, objective way to confirm the work meets the brief.
8. Timeline and any hard external dates
If there’s a campaign launch, a sale event, or a seasonal deadline the work needs to land before, say so explicitly at brief stage, not two weeks before the date. Hard deadlines change how a developer sequences work and what trade-offs are reasonable (e.g. shipping a simpler version on time versus a fuller version that risks the date).
A practical brief checklist
Before sending a brief to a developer or agency, check it covers:
- The underlying problem, not just the requested feature
- Current behaviour vs desired behaviour (with screenshots/recording where possible)
- Explicit scope boundaries, what’s included and what isn’t
- Your Shopify plan and theme (name/version if known)
- Any existing apps or custom code touching the same area
- Whether design is provided, referenced, or left to the developer
- Objective success criteria for the finished work
- Timeline, including any hard external dates
- Who on your side can answer follow-up questions quickly (a single point of contact speeds up almost every project)
- Budget expectations, even a rough range, this helps a developer propose the right-sized solution rather than either over- or under-building relative to what you’re prepared to spend
What good developers do with a good brief
A brief covering the above doesn’t remove the need for a scoping conversation, it makes that conversation far more productive. A developer working from a solid brief can come back with clarifying questions that actually matter (rather than basic ones the brief should have answered), flag a simpler native-Shopify way to solve the problem you didn’t know existed, and give you a quote that’s less likely to change once work starts.
When to bring in a specialist to help write the brief itself
For genuinely complex builds, custom checkout logic, B2B pricing structures, headless implementations, even experienced merchants often don’t know enough about what’s technically possible on Shopify to write a brief that captures the right scope on their own. In that situation, a short scoping/discovery engagement with a Shopify consultant before you brief a developer for the build itself is usually worth the cost, it turns a vague ambition into a brief a developer can actually quote against accurately.
FAQ
Do I need a written brief for small changes, like a copy update or a colour tweak?
No, a written brief is worth the effort for anything involving new functionality, layout changes, or integration with existing apps. For genuinely small, low-ambiguity tasks, a clear message with a screenshot is fine.
Should I get quotes from multiple developers using the same brief?
Yes, and it’s one of the best reasons to write a proper brief in the first place, a consistent brief lets you compare quotes on a like-for-like basis, rather than comparing responses to three different interpretations of a vague request.
What if I don’t know the technical details, like whether something needs an app or custom code?
That’s fine to leave open, state the problem and desired outcome clearly, and explicitly note that you’re open to the developer recommending the best technical approach. Good developers would rather you flag that you’re unsure than guess at technical terms incorrectly.
How much detail is too much detail in a brief?
If you’re specifying exact CSS values or dictating a specific technical implementation without a clear reason, you may be over-constraining a developer who could otherwise recommend a better approach. Focus your detail on the problem, desired behaviour, and scope boundaries; leave implementation specifics to the developer unless you have a firm reason to dictate them.
Should the brief include budget?
Yes, at least a rough range. Developers can propose a meaningfully different (and often better-fitting) solution when they know the budget envelope upfront, rather than guessing and either over-engineering or under-delivering relative to what you’re prepared to spend.
Get help scoping your next project
If you’re not sure how to translate what you want into a brief a developer can actually quote against, book a call with our team, we’re happy to help you think it through properly before you commission the work.
