Custom Software Development
Custom web and mobile applications built around your business processes, system integrations and modernization of legacy applications. We build applications that are cloud-ready, testable and easy to operate, and keep them running after launch with maintenance and support.
- Scope
- Web and mobile applications, APIs and integrations, internal tools, modernization
- Approach
- Short iterations and regular demos; automated testing, deployment and security scanning
- Support
- Post-launch maintenance and support under a support agreement
- First step
- Free initial consultation, followed by discovery and a current-state review
When does custom software make sense?
Well-designed custom software reduces manual work and organizes the flow of data between systems. First, we look together at whether an off-the-shelf product already meets your needs.
- Business processes run on spreadsheets and email. Bringing the data into a single application reduces duplicate entry and the risk of errors.
- Data is moved between systems by hand. Automated, API-based data flows can connect accounting, CRM and operations systems.
- An existing application needs to be renewed. Applications on aging technology, or ones that have become hard to develop, can be modernized step by step without interrupting use.
- A software project was left unfinished. The state of the existing code, infrastructure and documentation needs to be reviewed to decide how to move forward.
What do we cover in custom software development?
From idea to production, shaped by what your business needs.
Web applications
Internal operations tools, customer portals and admin dashboards; interfaces that work across devices.
Mobile applications
iOS and Android apps for field teams, customers and business partners, together with their backend services.
API and system integration
Secure APIs, data transfers and automations that connect your existing systems to each other.
Legacy system modernization
Moving legacy applications to a new architecture module by module, with a period of parallel running and controlled data migration.
Code and architecture review
An evaluation of the existing codebase, architecture and technical debt; a prioritized improvement report.
Maintenance and support
Clearly scoped post-launch support for monitoring, security updates, bug fixes and new development.
Why do we modernize legacy systems gradually?
Rewriting a system from scratch risks missing business rules built up over the years and going a long time without a usable result. That is why we modernize step by step.
Piece-by-piece transition
New modules go live alongside the old system, and usage is shifted to the new structure step by step.
Parallel running
The old and new systems run side by side for a while; each step is verified by comparing their results.
Controlled data migration
Data is migrated with validation steps at every stage, consistency checks and a rollback plan.
Reversible steps
Steps are planned so that, where possible, only the affected step is rolled back if a problem occurs; risk is split into small pieces.
Common signs that modernization is needed: the application runs on a platform that is no longer supported, changes take a long time, documentation is incomplete, or knowledge of the system is concentrated in a few people.
A phased process from discovery to launch.
What will be delivered at the end of each phase is clear from the start. Regular demos let you see the progress as well.
Discovery and current-state review
We look at your business processes, users and goals together. If there is an existing application, we also review its code, infrastructure and risks.
Output: Current-state map, prioritized backlog, risk listScope and solution presentation
We present the proposed solution, early screen mockups and the technical approach.
Output: Scope, mockups, technical proposalPlanning
We break the work into prioritized, short delivery cycles.
Output: Phased project planDevelopment and testing
We develop in short cycles and show a working version at the end of each one; testing and deployment run through automated pipelines.
Output: Working interim releasesLaunch and support
We take the application live and brief your users, then keep it running together with you under a maintenance and support agreement.
Output: Live application, documentation, support planWhat you have at launch.
The application goes live in a form that can be operated and sustained; the details of the deliverables are defined in the project scope.
Automated testing and deployment
Testing and deployment pipelines set up and documented.
Monitoring and alerts
Monitoring and alerts that show the application's health and performance.
Technical documentation
Architecture, installation, configuration and API documentation.
User guide and training
Guides and hands-on training for end users and administrators.
Maintenance and support plan
Clearly scoped support for updates, bug fixes and new development requests.
Security checks
Code review plus dependency and security scanning, built into the process.
How do we choose technologies?
Technology choices are driven by the project's needs, your existing systems and long-term ease of maintenance. Below are widely used, long-supported technologies we often work with.
Backend
- Java / Spring
- .NET (C#)
- Go
- Python
- Node.js
- PHP
Frontend
- React
- Angular
- Vue.js
- TypeScript
Mobile
- Kotlin (Android)
- Swift (iOS)
- Flutter
- React Native
Data
- PostgreSQL
- MySQL
- Microsoft SQL Server
- Oracle
- MongoDB
- Redis
Integration
- REST
- GraphQL
- Kafka
- RabbitMQ
Software projects sized to your scale.
SMEs
Bringing work done in spreadsheets and email into a single application, and connecting systems to each other.
Growing companies and startups
Launching the first version on solid foundations and continuing development as the product grows.
Organizations tied to legacy systems
Those who want to renew a working system module by module, in measurable steps, without putting it at risk.
Making the first meeting productive.
None of these are prerequisites; whatever you have makes the first meeting more concrete.
What you can prepare, if available
- A short description of today's workflow, plus the spreadsheets, forms or screenshots you use
- Who will use the application, and in which roles
- A list of systems to connect to (such as accounting, CRM or ERP)
- If there is an existing application, its code repository and documentation
About custom software development
References and standards
- OWASP ASVS (opens in a new tab)Application security verification standard
- OpenAPI Specification (opens in a new tab)Standard for describing API contracts
- Strangler Fig approach (opens in a new tab)Incremental modernization pattern
- The Twelve-Factor App (opens in a new tab)Principles for cloud-ready applications
Let's clarify your software needs together.
In a free initial consultation we discuss your current situation and goals, and share our first impressions and possible next steps in the same meeting.
- A technical conversation with specialists in your area
- First impressions of your situation and possible approaches
- Where it fits, a next step: an assessment, a project proposal or consulting
- A non-disclosure agreement before the meeting when needed
- A reply within 4 business hours
Software development examples from practice
Illustrative scenarios showing how modernization, integration and the release flow progress.
Incremental modernization of a legacy system
The legacy application is not replaced in one go; a routing layer is placed in front of it and modules move to the new structure one by one. A way back stays open at every step.
Current system
The legacy application's modules, data flows and business rules are mapped.
- monolith: 9 modules · 1 database · 86 screens
Routing layer
A routing layer is placed in front of the application; nothing changes for users.
- route /* → legacy-system
First module
A module with few dependencies and a strong need for change is built in the new structure.
- new service: quote-service
- ✓ tests: 312 passed
Parallel run
For a period, both systems run side by side and their results are compared.
- 10,000 requests compared · differences: 0
Traffic cutover
The relevant routes are directed to the new service; rolling back is a single setting.
- route /quotes/* → quote-service
- ✓ legacy module switched to read-only mode
Next module
The same steps are repeated for the next module; the legacy system shrinks until it is retired.
- migrated: 3/9 modules
- API gateway
- .NET / Java
- Automated tests
ERP and e-commerce integration
The systems do not wait on each other directly; events travel through a queue. The same record is not processed twice, and transient errors are retried automatically.
API contract
The fields and rules between the two systems are written down as an API contract.
- openapi: 3.1.0
- POST /orders · GET /stock/{sku}
Event
An order placed in the e-commerce system is written to the queue as an event.
- publish order.created id=S-10482
Transfer
The integration service passes the order to the ERP; the same order is not processed twice.
- POST /erp/orders Idempotency-Key: S-10482
- ✓ 201 Created
Error handling
If the ERP is temporarily unavailable, the request is retried at increasing intervals; requests that still fail are tracked in a separate queue.
- ! attempt 1: 503
- ! attempt 2 (after 4 s): 503
- ✓ attempt 3 (after 16 s): 201
Monitoring
Queue length and error rate are tracked on a dashboard; an alert fires if a threshold is crossed.
- queue: 0 · last 24 h: 1,284 orders · errors: 0
- OpenAPI
- RabbitMQ
- REST
- Monitoring
Release flow and quality
Work items are written with acceptance criteria, and every change is reviewed and tested. Releases go live through an automated deployment pipeline.
Prioritization
Work items are written with acceptance criteria and prioritized together with you.
- Sprint 7 · 11 work items
- goal: quote approval flow
Code review
Every change is reviewed by a team member; automated tests run before merging.
- PR #318 · 2 approvals
- ✓ tests · ✓ security scan
Demo
At the end of each sprint, the working software is reviewed together in the test environment.
- demo: quote approval flow
- feedback: 4 items
Release
The approved version goes live through the automated deployment pipeline, and release notes are shared.
- ✓ v1.7.0 live
- release notes published
Production monitoring
After the release, error and performance indicators are monitored.
- error rate 0.1% · p95 210 ms
- Jira / Azure Boards
- GitHub / GitLab
- Automated tests
- CI/CD