Custom Software Development
A system that runs on your own business rules, for processes packaged software cannot fit — from process analysis to data migration and a go-live without downtime, in a 12–32 week band.
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Custom software development turns a business process that packaged products do not cover into a system that runs on the organisation's own rules and whose data the organisation owns. GG Tech Teknoloji's Custom Software Development service starts from the process, not the code: who approves what, where each record is born, what has to move over from the old system. Then come the shared data model, the integrations, verification in a test environment and a go-live that never stops the old system; our planning band is 12–32 weeks.
| Typical team | 1 PM + 2-3 developers + 1 business analyst |
|---|---|
| Calendar band | 12–32 weeks |
| Phase split | 20% analysis · 50% development · 20% testing · 10% rollout |
What grows the budget
- Legacy integrations
- Data migration
- Number of business processes
- On-site training
Signs of underbudgeting
- Requirements never frozen
- Domain knowledge held by one person
These are GG Tech Teknoloji planning bands, not a quote; starting prices are on each service page. Every project is different, so the bands are deliberately wide; they assume a senior, focused team and typical scope, and your project is estimated individually.
Who is it for?
- Organisations patching packaged software with spreadsheets and manual workarounds to make it fit their process.
- Businesses that keep the same information in several systems and cannot say which record is the right one.
- Institutions such as municipalities that must talk to outside agencies' services and cannot afford an interruption in service.
- Companies that want to turn their own business model into software — and own the source of that software.
When is it the wrong choice?
- Your process matches the industry standard and a packaged product covers it: licence and maintenance will cost less than building.
- Requirements are still open and nobody has the authority to decide: a short analysis or product strategy engagement is the better first step.
- What you need is a form or a report screen that takes a few weeks: there is no reason to open a full system project.
How do we work?
- 1
Process analysis
We map the work itself, not the screens: which document goes from whom to whom, who signs off, how exceptions get resolved. Decisions are written down with a business analyst, so the knowledge stops living in one employee's head.
- 2
Buy-or-build decision
If an off-the-shelf product covers part of the process well, we say so. Custom code is written only where it sets you apart or where the package forces you into its mould.
- 3
One shared data model
Places where the same information is kept twice are untangled, and every record gets a single owner. At Çekmeköy, the data six applications each held separately came together in one model at this step.
- 4
Integration and data migration
Gateways to the systems you already run — accounting, ERP, public-sector services — are written; legacy data is cleaned and moved in trial runs. A migration is rehearsed, not done once.
- 5
Verification in a test environment
The new system is brought up in full in a separate environment and tested against real scenarios. The acceptance criteria are the process steps written during analysis.
- 6
Go-live and training
The new system waits ready while the old one keeps serving; the switch happens in a planned window with the way back left open. User training and a handover document are part of the delivery.
What do we deliver?
Custom Software Development
What sets the timeline and cost?
In our estimation model, custom software development sits in a 12–32 week calendar band — the widest of our services, because the process sets the timeline, not the technology. What grows the budget most is integration with legacy systems, data migration, the number of processes in scope and on-site user training. Requirements that never freeze and business knowledge held by one person are the two earliest signs that a budget will not hold. Custom software pricing depends on scope; you get a written proposal after the analysis. The Cost Drivers page has the detail.
See the cost driversProof from production
6
separate applications' data now in one central system (Çekmeköy Municipality)
0
minutes of downtime; the switch ran in a one-hour window at night (Çekmeköy Municipality)
100+
data models in one schema, four roles on the same model (Başarı Platformu)
Application and model counts were read from source code (September 2026); the cutover window and downtime come from the team that ran the cutover.
Read the case study: Çekmeköy BelediyesiFrequently asked questions
Off-the-shelf or custom software?
How long does custom software development take?
How do you replace a live system without shutting it down?
Which technologies do you use?
Who owns the source code and the IP?
How is maintenance handled after go-live?
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Clutch 5.0 · team of 20 · Çekmeköy Municipality, NSC Soft, UKX
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