How Long Does Custom Software Development Take? A Realistic Timeline Guide

"How long will it take?" is the second question every business asks about custom software (right after "How much will it cost?"). Unfortunately, the honest answer is: it depends. But we can give you realistic expectations based on project type and complexity.

This guide breaks down typical timelines and the factors that influence them.

Quick Reference: Typical Timelines

• Simple MVP: 6-10 weeks
• Medium Web App: 3-5 months
• Complex Web App: 6-9 months
• Mobile App (Single Platform): 3-5 months
• Mobile App (Cross-Platform): 4-6 months
• Enterprise System: 9-18+ months
• SaaS Platform: 6-12 months

Project Phases Explained

Understanding each phase helps set realistic expectations:

1. Discovery & Planning (2-4 weeks)

What happens:

• Requirements gathering
• User research and personas
• Technical architecture planning
• Feature prioritisation
• Project scope definition

Why it matters: Skipping discovery is the most common cause of delays and budget overruns. Every hour spent in discovery saves 5-10 hours in development.

Common timeline: 2-4 weeks

2. Design (2-6 weeks)

What happens:

• Wireframing and information architecture
• UI design and visual styling
• Prototyping key interactions
• Design system creation
• Usability testing

Why it matters: Good design prevents expensive redesigns during development. Changes in Figma take hours; changes in code take days.

Common timeline: 2-6 weeks depending on complexity

3. Development (6-20+ weeks)

What happens:

• Frontend development
• Backend development
• Database design and implementation
• API integrations
• Testing throughout

Why it matters: This is where most of the work happens. Rushing development creates technical debt that slows future progress.

Common timeline: 6-20+ weeks depending on scope

4. Testing & QA (2-4 weeks)

What happens:

• Functional testing
• Performance testing
• Security testing
• User acceptance testing
• Bug fixes and refinement

Why it matters: Launching with bugs damages user trust and creates emergency fix cycles that disrupt planned development.

Common timeline: 2-4 weeks (often overlaps with development)

5. Deployment & Launch (1-2 weeks)

What happens:

• Server setup and configuration
• Data migration
• Production deployment
• Monitoring setup
• Team training

Why it matters: Rushed launches cause outages. Proper deployment planning ensures smooth go-lives.

Common timeline: 1-2 weeks

MVP Timeline: The 6-12 Week Sweet Spot

A Minimum Viable Product (MVP) should typically take 6-12 weeks to build. Here's a realistic breakdown:

Week 1-2: Discovery and planning

• Define core problem and solution
• Identify must-have features
• Create technical architecture

Week 3-4: Design

• Wireframes for key screens
• Visual design for core features
• Prototype key interactions

Week 5-10: Development

• Core functionality
• Essential integrations
• Basic authentication and security

Week 11-12: Testing and launch

• Bug fixes
• Performance optimisation
• Deployment and monitoring setup

What an MVP Should Include

• Core value proposition features only
• Basic authentication
• Essential integrations
• Responsive design (web) or single platform (mobile)
• Error handling and basic security

What an MVP Should NOT Include

• Nice-to-have features
• Admin dashboards (use simple database tools)
• Advanced analytics
• Multiple language support
• Complex permission systems

Factors That Affect Timeline

1. Scope Clarity

Clear scope: Faster development, fewer surprises Vague scope: Delays, scope creep, budget overruns

Impact: Can add 25-50% to timeline

2. Decision-Making Speed

Every project requires hundreds of decisions. If stakeholders take a week to respond to questions, the project takes weeks longer.

Impact: Can add 20-40% to timeline

3. Number of Integrations

Each external system (payment processors, CRMs, accounting software) adds complexity:

• Simple integration: 1-2 weeks
• Complex integration: 3-6 weeks
• Legacy system integration: 4-12 weeks

Impact: Each integration adds 1-6 weeks

4. Design Complexity

Custom illustrations, animations, and unique interfaces take longer than using established design patterns.

Impact: Can add 2-6 weeks

5. Team Size and Experience

Senior developers work faster and make better architectural decisions. Larger teams can parallelize work but require more coordination.

Impact: Varies significantly

Common Causes of Delays

1. Scope Creep

"Can we also add..." is the most expensive phrase in software development. Each addition ripples through design, development, and testing.

Prevention: Freeze scope after discovery. Add new features to a "Phase 2" list.

2. Unclear Requirements

Vague requirements lead to incorrect assumptions, rework, and frustration.

Prevention: Invest in thorough discovery. Write specific user stories with acceptance criteria.

3. Slow Feedback

Development without regular client feedback leads to building the wrong thing.

Prevention: Weekly demos. Quick responses to questions. Designated decision-maker availability.

4. Technical Debt

Rushing early development creates bugs and architectural problems that slow later work.

Prevention: Allocate time for code quality. Don't sacrifice testing for speed.

5. Integration Surprises

Third-party APIs often don't work as documented. Legacy systems have undocumented quirks.

Prevention: Build integration spikes early. Add buffer for external dependencies.

6. Perfectionism

Polishing features endlessly delays launch. Perfect is the enemy of good.

Prevention: Define "done" criteria upfront. Launch MVP, iterate based on feedback.

Realistic Expectations by Project Type

Simple Internal Tool

Timeline: 6-10 weeks

• Basic CRUD operations
• Single user role
• Standard integrations
• Simple reports

Customer Portal

Timeline: 12-16 weeks

• Authentication and user management
• Dashboard with data visualisation
• Document management
• Email notifications

E-commerce Platform

Timeline: 14-20 weeks

• Product catalogue
• Shopping cart and checkout
• Payment integration
• Order management
• Basic admin panel

SaaS Product (MVP)

Timeline: 16-24 weeks

• Multi-tenant architecture
• User onboarding
• Subscription management
• Core product features
• Basic analytics

Mobile App with Backend

Timeline: 16-24 weeks

• Backend API development
• Mobile app (cross-platform)
• Push notifications
• Offline functionality
• App store submission

Working With Timelines

Getting Accurate Estimates

1. Provide detailed requirements - More detail = more accurate estimates
2. Share existing materials - Mockups, process documents, similar products
3. Identify constraints - Hard deadlines, budget limits, technical requirements
4. Discuss priorities - What's essential vs nice-to-have?

Managing During Development

1. Weekly check-ins - Review progress, discuss blockers
2. Working software over documentation - See actual features, not just reports
3. Quick decisions - Delayed decisions delay projects
4. Scope discipline - New ideas go to Phase 2

When Timelines Slip

1. Understand why - Scope change? Technical challenge? Resource issue?
2. Reassess scope - Can anything be cut or deferred?
3. Communicate early - Surprises at the end are worse than updates along the way
4. Avoid crunch - Overworking developers creates more bugs and delays

Key Takeaways

1. Most MVPs take 6-12 weeks with focused scope and clear requirements
2. Discovery prevents delays - Every hour spent planning saves development time
3. Integrations add significant time - Budget extra for external systems
4. Decision speed matters - Slow feedback extends timelines substantially
5. Scope discipline is essential - Feature additions ripple through the entire project
6. Build in buffer - Add 20% to any estimate for unknown unknowns

Ready to discuss realistic timelines for your project? Contact us for a free consultation where we'll help you plan a development roadmap that fits your goals.