This is part one of a two part blog series covering how to get your SaaS idea to market from idea to launch. In this first part I will cover the steps needed to get you from idea to choosing the tech stack you will need.
If you have an idea for an online service but do not know where to start, then read on and hopefully this article can help. I have over two decades of creating and running businesses and 6 years of developing websites and applications. In this article, I have tried to bring all of that together and provide a guide that can help aspiring founders. Let’s start with defining what a SaaS is and then move onto how to identify your opportunity and get it launched.
What is SaaS?
Software as a Service (SaaS) is a cloud based software delivery model where users access applications through a web browser while the provider hosts, maintains, and updates the infrastructure. Instead of one time licences, customers pay a recurring subscription. Well known SaaS products include Slack, Shopify, and Salesforce.
Does the world really need another Saas?
Market Reality 2025 – Is SaaS Saturated? There are now ~30 000 SaaS vendors globally (ascendixtech.com) and enterprises juggle an average of 275 apps. While industry revenue is still projected to top $390 B in 2025 and grow 13–19 % CAGR through 2029 (venasolutions.com), expansion rates have slowed—from 17 % in 2023 to 14 % in 2024, with forecasts of ~12 % for 2025 (sapphireventures.com). Translation: the low hanging fruit is gone, customer acquisition costs are higher, and table stakes features (SSO, SOC 2, AI assist) keep rising. New entrants win by:
- Going narrow (vertical or workflow specific SaaS).
- Embedding AI natively to 10× productivity.
- Exploiting under served geographies or channels.
If your target market is not enterprises, but consumers then it’s worth noting that the average U.S. consumer now holds 8.2 paid subscriptions and spends ≈ $118 per month on them, yet leaves 3.3 of those unused in a typical month.(whop.com, media.thinkbrg.com). (data only available for the USA).Reports of unfair price hiking is common and the US regulator and the EU are responding with rules to make it easier for users to cancel their subscriptions. Implication for new entrants:
- Solve an acute, habit forming problem—nice to haves get axed first.
- Offer clear ROI (time saved, money saved, joy delivered) and be transparent on renewal.
- Build sticky loops (social, data, creator content) to curb quarterly churn.
- Consider freemium or usage based tiers that let consumers “pay as they see value.”
So there is still lots of real growth available, but you have to target your market carefully and work to keep your subscribers happy.
Evaluating your idea
Your idea should solve a painful, frequent problem that businesses / users already spend money or time to solve. Write down the idea in a single sentence, confirm that it’s a problem that occurs frequently, confirm that people already spend money or time to solve it.
Size the opportunity with TAM, SAM and SOM
- TAM – Total Addressable Market: Everyone who could conceivably pay for a solution like yours if there were no competitors or constraints.
- SAM – Serviceable Available Market: The subset of the TAM that your business model and channels can realistically serve today.
- SOM – Serviceable Obtainable Market: The share of the SAM you can credibly capture in the next 1–3 years given your resources and competition.
- Build simple spreadsheet models (top down + bottom up) to sanity check the numbers.
- Look for niches >£10 m annual spend before you aim for the billions.
Top tip: It is so easy to get caught up in the excitement and be too optimistic about what is achievable. What I have done in the past is model the minimum SOM you need to make the businesses viable. A realistic SOM/ SAM ratio is 1% - 10% and SAM/ TAM will likely be <1% for the first 1-2 years of go-to-market. Early-stage founders often target 1–5% of SAM as their realistic launch-phase SOM. If you need more than this to make your business viable, then it might be time for a re-think.
Scan the competitive landscape
- List direct competitors and “good enough” substitutes.
- Note gaps in pricing, UX, or target segment.
Customer discovery “Lite”
- Do 15 problem interviews (Jobs to Be Done style). Find people to interview and get a sense of the problem you are trying to solve and the kind of solutions they might be attracted to.
- Launch a quick landing page + email capture. Explain the product/ service and the value it will bring when launched. Get users to email to be on early bird offers.
Checkpoint: If you can’t find 5 strangers willing to pay, rethink the idea.
Clarify the core value proposition
One sentence to rule them all "For [segment] who [struggle with], Product is a [category] that [solves problem] unlike [alternative]."
Build a Fake Marketing Site
• Write headline, sub headline, 3 bullets, CTA.
• Forces clarity on benefits vs features.
Define Your Success Metrics
• North Star Metric (e.g. “Reports sent per user per week”).
• Guardrails: activation, retention, referral, revenue.
If at the end of this process you are now feeling excited and feel your on to a winner, then you can begin the process of building the application. However, do not rush into this without some careful planning.
Plan before you code
Time spent here can not only make the difference between launching the right product but can save you thousands in costs.
Draft Lean Requirements
• Epics → user stories → acceptance criteria. Map User Flows • Visualise key journeys (signup → first value, billing, cancellation).
Slice an MVP
• Minimum Viable Product = the smallest set of features that delivers core value to a narrow segment and lets you learn. MoSCoW Priority Grid
MoSCoW
Must Non‑negotiable essentials—without them the MVP fails or breaches compliance. Should High‑value items with work‑arounds; can slip briefly without derailing launch. Could Nice‑to‑have polish or optimisations that delight but aren’t critical. Won’t (this time) Explicitly out of scope to preserve focus and budget.
Choosing a Platform & Tech Stack
Option 1
Responsive Web App (React, Vue, etc.)
Pros
Single codebase, works on any device, no app‑store gates.
Cons
Needs strong mobile UX, browser limits hardware APIs
Typical time to MVP
4–12 weeks
Option 2
Progressive Web App (PWA)
Pros
Offline, installable, push notifications
Cons
iOS limitations, cache complexity
Typical time to MVP
4–12 weeks
Option 3
Native Mobile (Swift/Kotlin)
Pros
Best performance, app‑store discovery
Cons
Two codebases, higher cost
Typical time to MVP
8–20 weeks
Option 4
Cross‑Platform (Flutter, React Native)
Pros
One codebase, near‑native UX
Cons
Larger bundle, some platform quirks
Typical time to MVP
6–16 weeks
Reality Check: 90 % of early‑stage SaaS starts as a responsive web app—cheapest to build, easiest to iterate.
Wrapping Up: From Idea to Execution
You’ve now taken the first big step: transforming a vague idea into a well-scoped, research-backed SaaS concept with a clear audience, a sharpened value proposition, and a realistic plan for development. You’ve assessed the market, validated demand, scoped your MVP, and considered the best tech stack to bring it all to life. Most importantly, you’ve laid the groundwork to avoid costly missteps and build something that people actually want.
In Part Two, we’ll move from planning to execution. We’ll cover how to actually build and launch your SaaS—everything from choosing developers (or building it yourself), setting up your infrastructure, implementing your MVP, managing feedback, and planning your go-to-market strategy.
Building a SaaS isn’t easy—but with a clear strategy and focused execution, it’s absolutely achievable.
Stay tuned for part two: “Building and Launching Your SaaS: From MVP to Market”
Glossary of Key Terms & Acronyms
SaaS (Software as a Service): A software delivery model where applications are accessed via the internet and hosted by the provider. Users typically pay via recurring subscriptions.
MVP (Minimum Viable Product): The simplest version of your product that delivers core value to users and allows you to validate your idea with minimal investment.
TAM (Total Addressable Market): The total demand for your product or service if you could reach every possible customer in the world with no constraints.
SAM (Serviceable Available Market): The segment of the TAM that your product can realistically serve based on your current business model and delivery channels.
SOM (Serviceable Obtainable Market): The realistic portion of the SAM you expect to capture in the near term (e.g., 1–3 years), based on your resources and competition.
Value Proposition: A clear statement of the unique benefits your product offers to a specific customer segment, and how it solves their problem better than alternatives.
North Star Metric: The single most important metric that best captures the core value your product delivers to users (e.g., messages sent, reports generated, hours saved).
MoSCoW Method: A prioritization framework used to define MVP features:
Must – Essential for launch or compliance.
Should – High-value but not critical.
Could – Nice-to-have enhancements.
Won’t (this time) – Out of scope for now.
User Story: A simple description of a feature or requirement from the end-user’s perspective (e.g., "As a user, I want to export my data so I can analyze it").
Acceptance Criteria: Conditions that a feature must meet to be accepted as complete (e.g., "User can export in CSV and JSON formats").
Epics: Large user stories or feature groups that can be broken down into smaller user stories.
User Flow: A visual or written outline of the steps a user takes to complete key tasks within your app (e.g., signup → trial → first use → payment).
Responsive Web App: A website designed to adapt to different screen sizes and work well on both desktop and mobile browsers.
PWA (Progressive Web App): A web application that uses modern web capabilities to deliver an app-like experience, including offline access and push notifications.
Native App: An application built specifically for a particular mobile platform (e.g., iOS or Android) using platform-native languages (Swift, Kotlin).
Cross-Platform App: An app built using frameworks like Flutter or React Native that allows for a single codebase to be deployed on both iOS and Android.
CAC (Customer Acquisition Cost): The total cost of acquiring a new customer, including marketing and sales expenses.
Churn Rate: The percentage of customers who cancel or stop using your service within a given period.
Retention: A measure of how many users continue to use your product over time, a key indicator of product-market fit.
Freemium Model: A pricing strategy where users can access a basic version of your product for free, with paid tiers offering additional features.