Custom Software Built to Scale.
Web apps, SaaS platforms, dashboards and internal systems engineered for reliability. Delivered by Dev4ager via Koldconvert across the full lifecycle: discovery, design, build and maintenance.
What is Custom Software and Platform Development?
Custom software and platform development is the process of designing and building digital products, web applications and internal systems to specification rather than adapting off-the-shelf tools. It covers everything from SaaS products and marketplaces to operations dashboards and enterprise backends. The output is purpose-built software owned entirely by the client, aligned precisely to the business logic, user roles and performance requirements of their organisation.
Signs You Need Custom Software Development
- Your team is managing operations in spreadsheets or a patchwork of tools that do not communicate with each other.
- You have validated a product idea but cannot ship it with existing no-code tools because of performance, logic complexity or integration requirements.
- Your SaaS product has outgrown its initial codebase and is slowing down feature delivery, causing reliability issues or failing under load.
- You are paying per-seat licensing fees for software that only covers 60% of your workflow, forcing manual workarounds for the rest.
- A previous agency delivered code but no documentation, monitoring or clear ownership, leaving your product impossible to extend without a full rewrite.
Who This Is For
SaaS Founders
Founders who have validated demand and need to build a production-grade product that can support paying customers, handle growth and attract further investment. We take you from wireframes to live product with full infrastructure ownership.
Scale-up Product Teams
Product teams that need additional engineering capacity to accelerate a roadmap, tackle technical debt or build a specific high-complexity feature without growing the permanent headcount permanently.
Operators Replacing Manual Processes
Operations-heavy businesses replacing spreadsheets, legacy tools or manual workflows with purpose-built internal systems. The ROI is in hours saved and errors eliminated per week.
Enterprises Modernising Systems
Larger organisations migrating from outdated software to modern, maintainable architecture. We handle the audit, refactor and migration plan so the transition does not disrupt live operations.
What You Get
- Technical Architecture Document System design, data models, service boundaries and infrastructure decisions documented before a single line of code is written.
- Interactive UX Prototype Clickable prototype covering all primary user flows, reviewed and approved by stakeholders before development begins.
- Production Codebase Clean, documented code stored in a repository owned by you, with branch protection, code review policies and commit standards enforced throughout.
- Automated Test Suite Unit, integration and end-to-end tests covering critical paths, reducing regression risk during ongoing feature development.
- CI/CD Pipeline Automated build, test and deployment pipeline via GitHub Actions, so code moves from pull request to production with no manual steps.
- Infrastructure as Code AWS infrastructure defined in Terraform so environments are reproducible, auditable and can be scaled or replicated without manual configuration drift.
- API Documentation Full OpenAPI specification for every endpoint, enabling third-party integrations and future development without reverse-engineering the codebase.
- Runbooks and Handoff Materials Operational runbooks, incident response procedures and onboarding documentation so your team can operate the system independently from day one.
What We Build
Web Apps & SaaS
Customer-facing platforms, SaaS products, marketplaces and portals. Built for reliability, performance and scale from day one.
Mobile Applications
iOS and Android apps. Consumer apps, B2B tools and companion apps for existing platforms, using React Native for cross-platform efficiency.
Backend & Infrastructure
Databases, backend APIs, cloud infrastructure and DevOps pipelines. The architecture your product runs on, engineered to scale without firefighting.
Internal Tools & Dashboards
Operations portals, reporting dashboards, admin systems and internal workflow tools built for your team's exact process, not a generic template.
The Koldconvert Scalable Build Framework
Most software agencies build what you specify and stop. The Koldconvert Scalable Build Framework starts from business outcome, not technical specification. We begin every engagement by defining what the software needs to achieve at 10x current scale, then architect backwards from that constraint rather than forwards from current requirements. Architecture decisions, database schemas and API contracts are treated as durable assets, not temporary scaffolding. The framework mandates that observability, testing coverage and documentation reach production-grade before any feature is signed off, which is why our builds continue to perform years after handoff rather than accumulating technical debt from month one.
From Discovery to Deployed Product
Discovery & Scoping
Requirements mapping, architecture design and technical specification. Detailed scope with timeline and cost before any code is written.
Design & Prototyping
UI/UX design and interactive prototypes. You review and approve flows before development begins.
Build & Test
Iterative development with regular demos. QA testing throughout, not just at the end. Automated tests written alongside features.
Launch & Maintain
Deployment, monitoring setup and handoff. Ongoing maintenance, security patching and feature development retainer available.
Tools & Technology
Next.js serves the frontend with server-side rendering for performance and SEO. Node.js and Python handle API and background processing layers. PostgreSQL on Supabase provides a managed, scalable database. AWS manages cloud infrastructure defined in Terraform. GitHub Actions automates testing and deployment on every push. Docker ensures environment consistency from local development through to production.
How We Work Together
Fixed-Scope Project
Defined deliverables, fixed price, fixed timeline. Best for greenfield builds, MVPs and well-scoped features. Starts with a paid discovery sprint to define scope accurately. Typical duration: 8-24 weeks.
Development Retainer
Ongoing monthly capacity for feature development, maintenance and technical improvements. Ideal for funded startups and scale-ups with a continuous product roadmap. Minimum three-month engagement.
Technical Due Diligence & Audit
Codebase review, architecture assessment and technical debt report. Used before acquisition, investment or a major platform migration. Delivered in two weeks as a written report with scored findings.
What Clients Achieve
Build Outcomes
Software Development for Your Industry
FinTech & Payments
Payment processing platforms, lending engines, financial dashboards and compliance reporting systems. Built with PCI-DSS considerations from architecture stage and Stripe integration as standard.
HealthTech & MedTech
Patient management platforms, clinical data systems and telemedicine products. Architected with GDPR and HIPAA requirements addressed at the data model level, not bolted on post-build.
SaaS & B2B Software
Multi-tenant SaaS platforms with role-based access, subscription billing via Stripe, usage metering and enterprise SSO integration. Built to grow from 10 to 10,000 customers without rearchitecting.
E-commerce & Retail
Custom storefront backends, inventory management systems, order orchestration layers and warehouse management tools that go beyond what Shopify themes can support.
EdTech & Learning Platforms
Course delivery platforms, cohort management systems, progress tracking dashboards and assessment engines. Built to support live and asynchronous learning formats at scale.
Logistics & Supply Chain
Route optimisation tools, shipment tracking dashboards, carrier API integrations and warehouse operations portals. Built for real-time visibility across complex multi-carrier networks.
Legal Tech
Document automation platforms, matter management systems, client portals and contract analysis tools. Built with audit trail requirements and document versioning as core architecture constraints.
Real Estate Tech
Property listing platforms, lettings management systems, landlord portals and valuation tools. Integrations with land registry APIs, rightmove feeds and payment systems built as standard.
HR Technology
Applicant tracking systems, onboarding workflows, performance management tools and payroll integrations. Custom-built for organisations whose HR processes are too specific for generic HRIS platforms.
InsurTech
Quote and bind engines, policy management platforms, claims portals and broker tools. Actuarial logic embedded directly in the product, not maintained in spreadsheets outside the system.
Koldconvert vs In-house Development Team
| Factor | Koldconvert | In-house Team |
|---|---|---|
| Time to start | Discovery sprint can begin within 2 weeks | 3-6 months to hire, onboard and align a team |
| Cost predictability | Fixed-scope price agreed before build begins | Salary, benefits, tools and management overhead scale with headcount |
| Specialist coverage | Frontend, backend, DevOps, QA and design covered in one engagement | Each specialism requires a separate hire |
| Continuity across lifecycle | Same team from discovery through maintenance | Context lost when engineers leave or projects are handed between teams |
| Documentation and handoff | Architecture docs, runbooks and API specs delivered as standard | Documentation quality varies by individual engineer and is often deprioritised under delivery pressure |
| Scalability of resource | Capacity adjusts without HR process for each change | Scaling up requires hiring; scaling down means redundancy processes |
| Accountability for outcomes | Contractual milestones with agreed acceptance criteria | Performance management is an internal process requiring management bandwidth |
Most software projects fail not because of bad code but because the brief is wrong. Companies define requirements based on what they need today, then discover six months into a build that the architecture cannot accommodate the next stage of growth. We address this by treating the architecture review as the first deliverable, not a side note. The other pattern we see consistently is teams treating documentation and observability as optional extras to add after launch. By the time the system is live, the team is already on the next feature, and the documentation never gets written. We enforce documentation and monitoring as acceptance criteria on every sprint, which means the system is operable from launch day rather than becoming a black box six months later.
Koldconvert Strategy Team
Questions to Ask Any Software Development Partner
- Who actually writes the code, and will I speak to them directly? Many agencies use account managers as the only point of contact while work is done offshore by a separate team. A good answer names the lead engineer and confirms they join client calls.
- What does your discovery and scoping process produce, and what does it cost? A credible agency charges for discovery and delivers an architecture document and fixed-scope estimate from it. Free scoping estimates are usually guesses.
- How is testing handled, and what coverage standards do you enforce? Testing written after the fact indicates a development culture that treats QA as optional. A good answer confirms automated tests are written alongside features, with a minimum coverage threshold.
- What documentation and monitoring will be in place at launch? Vague answers suggest documentation will not be delivered. Expect specific outputs: OpenAPI specs, runbooks, architecture diagrams and monitoring dashboards configured before go-live.
- Can I see examples of codebases or projects similar to mine? Portfolio logos are not sufficient. Ask for a technical walkthrough of an architecture decision from a comparable project. The ability to explain trade-offs indicates genuine engineering depth.
Glossary
- MVP (Minimum Viable Product)
- An MVP is the smallest version of a product that delivers core value to users and can be tested in the market. It is not a rough prototype; it is production-quality software covering the primary use case with everything non-essential removed.
- CI/CD (Continuous Integration / Continuous Deployment)
- CI/CD is an automated pipeline that builds, tests and deploys code on every change. It removes manual steps from the release process, reduces human error and allows teams to ship code multiple times per day.
- Infrastructure as Code (IaC)
- Infrastructure as Code is the practice of defining cloud servers, databases and networking in version-controlled configuration files rather than configuring them manually through a console. Terraform is the primary IaC tool used across Koldconvert projects.
- Multi-tenancy
- Multi-tenancy is an architectural pattern where a single software instance serves multiple customers, with data isolated between them. It is the standard approach for SaaS platforms and requires deliberate architecture decisions at the database and access-control level.
- Technical Debt
- Technical debt is the accumulated cost of shortcuts, missing documentation and poor architectural decisions made during earlier development. It compounds over time, slowing feature delivery and increasing the cost of every future change.
- Observability
- Observability is the ability to understand the internal state of a system from its external outputs: logs, metrics and traces. A system with high observability surfaces errors, slow queries and unusual traffic patterns before they cause customer impact.
Software Development, Answered
We build web applications including SaaS platforms, marketplaces and admin dashboards; backend systems covering APIs, databases and cloud infrastructure; and internal tools such as operations portals, reporting dashboards and workflow systems.
An MVP typically takes 8-12 weeks. A full-featured SaaS platform takes 12-24 weeks. Timelines depend on scope complexity, number of integrations and user roles within the system.
MVP projects typically start from £30,000-£60,000 depending on scope. Full platforms range from £80,000-£250,000. We provide fixed-scope estimates after a discovery sprint so there are no surprises mid-project.
Next.js and React on the frontend, Node.js and Python on the backend, PostgreSQL for the primary database, AWS for cloud infrastructure, and Docker with GitHub Actions for CI/CD. Stack selection is based on performance, team and maintenance requirements for your specific project.
Building in-house is the right choice when you have an established engineering team and clear product requirements. Koldconvert is the faster option for companies that need production-quality software without the 3-6 month lead time required to hire, onboard and align an internal team.
Yes. We conduct a codebase audit first to assess quality, technical debt and architecture. The audit produces a written report before we commit to any timeline for extension, refactor or migration work.
Software is delivered with documentation, runbooks, monitoring and CI/CD pipeline in place. Dev4ager offers ongoing maintenance retainers and feature development from the same team that built the product, with no context loss from handoff.
Yes. We have experience taking ideas from zero to validated MVP. A paid discovery sprint helps define the minimum buildable scope before any development budget is committed, so founders invest in building the right thing rather than the full vision.
We build software across FinTech, HealthTech, SaaS, E-commerce, EdTech, Logistics, Legal Tech, InsurTech, Real Estate Tech and other sectors requiring reliable, scalable web applications.
The same team handles discovery, design, build and maintenance. We challenge specs when a different approach better serves the business outcome. Every deliverable includes tests, documentation and monitoring as standard, not as extras billed separately.
Yes. Mobile app development is a dedicated service covering iOS and Android, using React Native for cross-platform builds and Swift or Kotlin for native-performance requirements. See the mobile app development page for full details.
Security patching, dependency updates and vulnerability scanning are included in maintenance retainers. Critical security issues receive a 24-hour response window under retainer agreements.
Ready to build your software?
Book a call to discuss your product vision and get a scoping estimate.