The verdict in three sentences
A web app project is steered through 1 to 2 week sprints with a demo at the end of each sprint and continuous acceptance testing: this is what avoids the tunnel effect. The fixed-price vs time-and-materials choice decides who carries the scope risk and how much you pay when things change. Run well, an agile project holds a 3 to 9 month timeline depending on complexity and keeps budget under control through backlog prioritisation.
The stages and their deliverables
Agile is not organised chaos: each phase has an expected deliverable. Here are the 2026 markers.
| Phase | Deliverable | Typical duration | Who signs off |
|---|---|---|---|
| Discovery | Prioritised backlog + mockups | 2-4 weeks | Sponsor + Product Owner |
| Dev sprints | Tested increment each sprint | 2-6 months | PO + acceptance |
| Acceptance | Test plan + fixes | ongoing | Business users |
| Go-live | Deployment + training | 1-2 weeks | Sponsor |
| Warranty | Post-launch fixes | 1-3 months | Team |
The end-of-sprint demo is the key moment: it lets you reprioritise the backlog every two weeks, so you adjust scope before it gets expensive.
Fixed-price vs time-and-materials: who carries the risk
The contract model changes everything: fixed-price freezes scope, time-and-materials freezes the day rate. Most 2026 projects combine a fixed-price discovery then a capped time-and-materials phase.
| Criterion | Fixed-price | Time & materials | Capped T&M |
|---|---|---|---|
| Price | fixed (e.g. EUR 60,000) | 500-750 EUR/day | negotiated cap |
| Scope risk | vendor | client | shared |
| Change flexibility | low (change orders) | full | framed |
| Budget visibility | high | medium | high |
| Best for | stable scope | moving scope | evolving MVP |
To keep control of costs: scope first, set a budget cap, and use backlog prioritisation as the adjustment variable rather than timeline or quality.
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Mini case study
Thomas, project sponsor and deputy managing director of a distribution SME in Dublin, was torn between a rigid fixed-price and open time-and-materials. He chose a fixed-price discovery at EUR 9,000 then capped T&M at EUR 72,000 over 6 months (rate EUR 600/day, i.e. 120 days). Thanks to reprioritisation each sprint, two secondary features were deferred and replaced by a more urgent accounting integration, with no change order or extra cost. Result: delivery within the budget cap, a 6-month time-to-market met, and an app that fits the real need rather than the initial spec.
FAQ
What is a sprint in practice? It is a 1-to-2-week cycle at the end of which a working part is delivered and demonstrated. It lets you test early, fix fast and reprioritise what has the most value.
Who does what on the client side? You appoint an available Product Owner (a few hours a week minimum) who prioritises the backlog and signs off demos. Without that role, timelines slip systematically.
Fixed-price or T&M to limit risk? A fixed-price discovery then capped T&M combines the best of both: budget visibility and scope flexibility. It is the recommended pattern for an evolving MVP.
How do we avoid budget overruns? By freezing a budget cap and using the backlog as the variable: you arbitrate what comes first and defer the rest. Timeline and quality are never used as the adjustment variable.
How long does a typical project last? From 3 months for a simple MVP to 9 months for a business platform with integrations. Continuous acceptance and regular demos are what hold that schedule.
Let's scope your project. Tell us your need, your indicative budget and your target date, and we will propose a fixed-price discovery then capped agile delivery. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
