Custom Software Development Outsourcing Companies in the United Kingdom

We build custom software for clients who prefer to keep product ownership close while shifting delivery to a hands-on partner. Our work spans web platforms, business applications, and supporting services that make those systems practical day to day. We provide custom software development outsourcing in the United Kingdom and maintain active engagements with clients in the United Kingdom, including projects described on our UK pages and case library. 

Projects usually start with scoping and architecture, then move into iterative implementation with QA and release management running alongside. Team models are flexible – dedicated squads, team extension, or a mixed setup when that’s the quickest way to ship. Along the way, we handle interoperability through APIs and connectors so new components do not break what’s already in place. Web development and platform work sit next to cloud, testing, and the unglamorous upkeep that keeps a release steady once people start using it. 

Key Highlights:

• Custom software outsourcing for clients in the United Kingdom confirmed on the website
• Flexible engagement formats – dedicated teams and team extension
• Integration and APIs treated as core project scope
• Post-release support with planned improvements

Services:

• Custom application development under an outsourced model
• Dedicated engineering teams aligned with client ceremonies
• Team extension to add capacity for specific milestones
• Architecture, scoping, and delivery management
• API design, system integration, and connector work
• Website and portal development with iterative releases
• Quality assurance, automation, and release readiness

Contact Information:

• Website: Lengreo
• Contact Email: hi@lengreo.com
• Phone Number: +31 686 147 566
• LinkedIn: Lengreo
• Twitter: @Lengreo
• Instagram: @lengreo

Our cases

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N-iX works as a build partner for organizations that want to hand off delivery to an external engineering group without losing control over product quality or cadence. The scope typically spans discovery, architecture, implementation, and long-term lifecycle work, so a product does not stall after launch. Engagements often run through dedicated squads that extend an in-house team, with delivery managers, QA, and DevOps wrapped in from the start. Custom development sits alongside integration and modernization projects, letting platforms evolve rather than be rewritten every year. Cloud and data capabilities are positioned as part of the same delivery track, not add-ons. The result is an outsourced model that still feels embedded in the client’s roadmap and release rhythm. 

Highlights:

• End-to-end delivery that covers discovery through support
• Dedicated teams for long-running product work
• Cloud, data, and DevOps folded into core builds

Services include:

• Custom software design and development
• Dedicated development teams and team extension
• Product engineering, refactoring, and performance tuning
• System integration and API engineering
• Cloud architecture, migration, and platform enablement
• Data platforms, analytics, and machine learning support

Contact Information:

• Website: www.n-ix.com
• E-mail: contact@n-ix.com
• Facebook: www.facebook.com/N.iX.Company
• Twitter: x.com/N_iX_Global
• LinkedIn: www.linkedin.com/company/n-ix:
• Address: London, EC3A 7BA, 6 Bevis Marks, UK
• Phone: +44 203 740 76 69

Itransition positions custom development as a full-cycle service: from validating requirements to shipping and maintaining releases that fit existing business processes. Delivery spans web, mobile, and enterprise platforms, with attention to integration points so new components do not break the tools a company already runs. Discovery and solution architecture sit up front, followed by iterative build and QA, which keeps scope transparent while a product takes shape. Post-release, support and enhancement tracks continue under the same governance rather than being treated as a separate project. 

Where more capacity is required, Itransition fields dedicated teams that plug into a client’s stack and ceremonies. That model is used both for greenfield builds and for adding velocity to established products. Enterprise work frequently includes data exchange, security, and compliance gates handled inside standard delivery workflows. The emphasis is on keeping outsourced contributors aligned with internal stakeholders and KPIs rather than running a parallel process. 

Why people choose this vendor:

• Full-cycle custom development with clear handoffs
• Team augmentation available when extra capacity is needed
• Enterprise integration and governance practices included
• Attention to post-release support and continuous improvement

Core offerings:

• Custom application development across web and mobile
• Dedicated development teams with agreed roles and SLAs
• Enterprise system integration and data workflows
• Application modernization and re-platforming
• UX and interface implementation tied to product goals
• Quality assurance, automation, and performance testing

Contact Information:

• Website: www.itransition.com
• E-mail: info@itransition.com
• Facebook: www.facebook.com/Itransition
• Twitter: x.com/itransition
• LinkedIn: www.linkedin.com/company/itransition
• Address: London 3rd floor, 5-8 Dysart St., EC2A 2BX
• Phone: +44 203 687 2281

TatvaSoft focuses on building business software that fits specific workflows rather than generic templates. Discovery and solution design lead into implementation where engineering, QA, and deployment run in one stream, which helps reduce handover friction. Projects range from transactional systems to content and data platforms, with attention to how the new app connects to existing tools. The engagement is set up so a client can outsource delivery while retaining visibility of milestones and scope. 

Technology stacks cover mainstream web and mobile frameworks, along with common open-source components used for portals, ecommerce, and internal apps. Integration work is routine: APIs, connectors, and data exchange are treated as first-class tasks rather than afterthoughts. That approach helps products ship without manual bridges between systems. 

Beyond initial release, TatvaSoft continues with stabilization, optimization, and feature updates under the same delivery guardrails. Teams can be adjusted for a short acceleration phase or for a longer roadmap, depending on how the product evolves. This keeps outsourced development aligned with operational goals and service levels over time. 

Standout qualities:

• Solution design and build delivered as one stream
• Stack coverage across web, mobile, and common open-source tools
• Integration and data exchange treated as core scope

Service scope:

• Custom business application development
• Outsourced product builds with staged milestones
• System integration, API implementation, and connectors
• Ecommerce and portal engineering with content and transaction flows
• Quality assurance and automated testing
• Performance optimization and ongoing maintenance
• Cloud deployment and environment setup

Contact Information:

• Website: www.tatvasoft.co.uk
• E-mail: info@tatvasoft.co.uk
• Facebook: www.facebook.com/TatvaSoft
• Twitter: x.com/tatvasoft
• LinkedIn: www.linkedin.com/company/tatvasoft
• Address: 307, Euston Road, London NW1 3AD, United Kingdom
• Phone: +44 742 409 8452

Dotsquares takes on outsourced builds where a client wants custom software shaped around existing operations rather than squeezed into a template. Work usually starts with scoping and architecture, then moves into implementation with QA and release support running in parallel, so progress isn’t gated by handovers. Delivery spans web platforms, mobile apps, and back office systems, often with integration tasks to link CRMs, ERPs, and payment providers. The team also covers bespoke features that don’t fit off-the-shelf modules, from workflow tools to data dashboards. 

Key points:

• End-to-end delivery with QA and release support embedded
• Custom builds paired with system integration and API work
• Bespoke features for business-specific workflows
• Post-launch improvements planned as part of the engagement

Services include:

• Custom web and mobile development under an outsourced model
• Bespoke application design with iterative delivery
• Integration of third-party platforms and internal systems
• API engineering, data exchange, and connector setup
• Quality assurance, automation, and release management
• Cloud setup, performance optimization, and ongoing care

Contact Information:

• Website: www.dotsquares.com
• E-mail: office@dotsquares.com
• Facebook: www.facebook.com/dotsquaresuk
• Twitter: x.com/dotsquares
• LinkedIn: www.linkedin.com/company/dotsquares
• Instagram: www.instagram.com/dotsquaresltd
• Address: Unit 2 Hobbs Court, 2 Jacob Street, London SE1 2BG
• Phone: +44 208 0901819

Intellias structures outsourcing around full-cycle delivery, from discovery and solution design to production releases and maintenance. Custom development covers web, mobile, and platform engineering, with attention to compliance, scalability, and secure architectures. Enterprise work leans on integration patterns, so new services line up with tools already in place. The idea is to shorten the path from requirements to a stable release without losing visibility into scope or quality. 

When extra capacity or niche expertise is needed, the company fields dedicated squads that join a client’s ceremonies and toolchain. That model is used for greenfield builds, modernization, or adding velocity to an existing roadmap. Nearshore setups and team-extension options keep control with the product owner while shifting execution to an external crew. Governance and release practices stay consistent, which reduces context switching between internal and outsourced contributors. 

Why people choose them:

• Full-cycle custom development with architecture and security in scope
• Option to scale via dedicated teams plugged into client processes
• Integration patterns for enterprise stacks and data flows

Core offerings:

• Custom application engineering across web and mobile
• Team extension and dedicated delivery squads
• System integration, data pipelines, and API services
• Application evolution, re-platforming, and performance work
• QA automation, reliability practices, and CI/CD
• Cloud architectures, environments, and operational support

Contact Information:

• Website: intellias.com
• E-mail: info@intellias.com
• Facebook: www.facebook.com/Intellias.GlobalPage
• Twitter: x.com/intellias
• LinkedIn: www.linkedin.com/company/intellias
• Address: Guilford GU1 4QF, College Road, Andrews House, Suite 6, 2nd floor, UK
• Phone: +44 7899 043879

Innowise approaches outsourced builds as a continuous stream that starts with analysis and moves through implementation, testing, and rollout without hard breaks. Custom and platform-based development both show up in the portfolio, chosen by what fits the use case rather than a fixed preference. Delivery emphasizes clear cooperation models and methodology selection, so projects don’t get stuck over process debates. 

The custom track ranges from transactional systems to content and data-heavy applications. Teams align new components with existing services through APIs and connectors, making sure handoffs between systems are predictable. Where needed, the solution is adjusted for cost or schedule by swapping modules or deferring non-critical features, which keeps releases moving. 

Post-release, the focus shifts to stabilization and incremental enhancements, not just support tickets. Bespoke features are extended as usage patterns emerge, while performance work and cloud housekeeping keep the platform steady. The result is an outsourced setup that still feels connected to day-to-day operations. 

Standout qualities:

• Full-cycle delivery with flexible cooperation models
• Mix of custom and platform-based builds chosen by fit
• Integration first mindset for APIs and data exchange

Their focus areas:

• Custom product engineering with iterative releases
• Outsourced development with clear milestones and SLAs
• API design, connectors, and system interoperability
• Modernization and feature extension for live systems
• QA practices, test automation, and release readiness
• Cloud environments, monitoring, and performance tuning

Contact Information:

• Website: innowise.com
• E-mail: contact@innowise.com
• Twitter: x.com/innowisegroup
• LinkedIn: www.linkedin.com/company/innowise-group
• Address: London 55 Loudoun Road St. John’s Wood, NW8 0DL
• Phone: +44 7860 340 279

ELEKS runs outsourced builds as a continuous track – discovery, architecture, implementation, and lifecycle care sit in one flow so releases don’t stall between handoffs. Custom work ranges from transactional platforms to data-heavy products, with integration and modernization treated as core scope rather than side tasks. Delivery often uses dedicated teams that plug into a client’s ceremonies, while nearshore options keep collaboration hours aligned and feedback loops short. Cloud and analytics capabilities come bundled into product work, not as separate add-ons, which helps features move from idea to stable release without extra orchestration. 

Standout qualities:

• Full-cycle engineering with embedded QA and DevOps
• Nearshore and dedicated-team models for outsourced delivery
• Integration and modernization handled as first-class work
• Cloud and data capabilities aligned with product milestones

Service scope:

• Custom application design and development
• Dedicated squads for outsourced delivery
• System integration, API engineering, and data exchange
• Cloud architecture, migration, and platform enablement
• Quality assurance, automation, and CI/CD
• Post-release optimization and incremental enhancements

Contact Information:

• Website: eleks.com
• Facebook: www.facebook.com/ELEKS.Software
• Twitter: x.com/ELEKSSoftware
• LinkedIn: www.linkedin.com/company/eleks
• Address: Moor Place, 1 Fore Street Avenue, London, United Kingdom, EC2Y 9DT
• Phone: +44 20 4583 0843

Andersen positions custom development as a full project lane – discovery, solution design, implementation, and support live under one governance model. Product work spans web and mobile with attention to security, scalability, and compliance gates typical of enterprise stacks. Large initiatives are structured with clear ownership and risk control so scope changes don’t derail delivery. Integration patterns connect new services to existing tools, limiting manual workarounds and brittle data paths. 

When capacity needs to scale, dedicated teams join the client’s toolchain and cadence, which suits greenfield builds and modernization efforts alike. Startup programs exist alongside enterprise delivery, allowing lighter discovery and faster ramp while still retaining QA and release discipline. Web and mobile practices are backed by established frameworks and measurable release processes, which makes handoffs predictable. The same crews typically carry on after launch for stabilization and enhancements so knowledge doesn’t reset between phases. 

Why people choose this provider:

• Full-cycle delivery with architecture and governance in scope
• Option to scale via dedicated teams embedded in client processes
• Enterprise integration patterns to reduce operational friction

Core offerings:

• Custom application engineering for web and mobile
• Team extension and dedicated delivery squads
• System integration, data pipelines, and API services
• Application evolution, re-platforming, and performance work
• QA automation, reliability practices, and CI/CD
• Ongoing maintenance with planned feature increments

Contact Information:

• Website: andersenlab.com
• E-mail: vn@andersenlab.com
• Facebook: www.facebook.com/AndersenSoftwareDev
• Twitter: x.com/AndersenLabs
• LinkedIn: www.linkedin.com/company/andersen-lab
• Instagram: www.instagram.com/andersen.global
• Address: 30 St Mary’s Axe, London, EC3A 8BF, UK
• Phone: +44 207 048 6755

Vention treats outsourcing as a partnership focused on shipping usable software on a steady cadence. Custom builds cover platforms, mobile, and enterprise components, chosen by fit rather than a single preferred stack. Discovery, architecture, and delivery practices are designed to fold into a client’s roadmap so priorities stay visible and measurable. Consulting support is available when the plan needs hardening before code starts. 

For execution, the company fields engineering units that integrate through standard ceremonies and tooling. Architecture work aims at modular designs to keep future changes less painful, especially when traffic or data volumes grow. Where customer operations lean on CRMs or similar systems, interoperability is addressed early so connectors don’t become a late surprise. This framing reduces rework and shortens the path to stable releases. 

After go-live, support shifts toward incremental improvements – performance passes, backlog grooming, and targeted feature drops rather than big-bang rewrites. Outsourcing options include taking full ownership of delivery or augmenting an internal team to add velocity. Guidance materials and playbooks exist for vendor selection and collaboration structure, which helps stakeholders agree on how the engagement should run. 

What makes this firm different:

• Outsourced delivery paired with upfront consulting when needed
• Architectural focus on modularity and change readiness
• Interoperability and CRM connectivity planned early

Delivery focus:

• Custom application development across platforms and mobile
• Outsourced engineering with embedded ceremonies and SLAs
• Architecture design, audits, and evolution plans
• System interoperability, API design, and connector work
• Performance engineering, monitoring, and reliability practices
• Roadmap-driven enhancements and ongoing support

Contact Information:

• Website: ventionteams.com
• E-mail: hello@ventionteams.com
• Twitter: x.com/ventionteams
• LinkedIn: www.linkedin.com/company/ventionteams
• Instagram: www.instagram.com/ventionteams
• Address: London, 30 Churchill Place, E14 5RE
• Phone: +44 207 117 28 42

Classic Informatics takes on outsourced builds as a single delivery track where discovery, solution design, implementation, and upkeep move without clunky handoffs. Custom work spans web platforms, applications, and products, with integration and modernization treated as first-class scope rather than add-ons. The operating model pairs project governance with flexible resourcing, so capacity can expand for a milestone and contract when the roadmap quiets down. QA and DevOps sit inside the same stream to keep releases predictable and reversible when needed. Cloud and product engineering show up together, which helps ideas move from brief to stable release without a maze of separate vendors. The aim is straightforward – make software that fits the business and plugs cleanly into the existing stack. 

Highlights:

• End-to-end outsourcing with embedded QA and DevOps
• Custom builds paired with system integration and modernization
• Flexible resourcing aligned to product milestones
• Cloud and data capabilities included in core delivery

Services cover:

• Custom application and product development under an outsourced model
• Architecture, scoping, and delivery management
• API engineering, connectors, and platform interoperability
• Modernization, refactoring, and performance tuning
• Test automation, CI/CD, and release readiness
• Cloud setup, migration, and ongoing operations

Contact Information:

• Website: www.classicinformatics.com
• E-mail: hello@classicinformatics.com
• Facebook: www.facebook.com/classicinformatics
• Twitter: x.com/classicinfo
• LinkedIn: www.linkedin.com/company/classic-informatics-private-limited
• Address: 14 Bonhill Street, London, EC2A 4BX, United Kingdom
• Phone: +44 20332 23550

GoodCore frames outsourcing as full-cycle delivery, from clarifying requirements to shipping and supporting releases that fit day-to-day operations. Custom development covers web, mobile, and platform work, with attention to security and scalability where enterprise constraints apply. The approach keeps discovery close to engineering, which shortens the path from a sketch of a feature to something running in production. Integration is standard practice, so new components align with tools already in place. 

When a team needs extra capacity or a specific skill set, GoodCore supplies dedicated squads that plug into the client’s ceremonies and toolchain. That setup works for greenfield builds or for adding velocity to an existing product line. Guidance materials and practical outsourcing primers are published to help stakeholders shape the engagement before code starts. Post-launch, the same crews handle stabilization and iterative improvements, keeping context intact. 

Strengths:

• Full-cycle custom engineering with clear handoffs
• Option to scale via dedicated delivery squads
• Enterprise-minded integration and security practices
• Attention to post-release stabilization and iteration

Delivery scope:

• Custom web and mobile application development
• Team extension and managed outsourced delivery
• System integration, APIs, and data workflows
• Application evolution, re-platforming, and performance work
• QA automation, reliability practices, and CI/CD
• Cloud environments and operational support

Contact Information:

• Website: www.goodcore.co.uk
• E-mail: contact@goodcore.co.uk
• Facebook: www.facebook.com/goodcoresoftware
• LinkedIn: www.linkedin.com/company/goodcore-software
• Address: United Kingdom Airport House, Purley Way, Croydon CR0 0XZ
• Phone: 020 8781 6903

Pulsion focuses on outsourced custom software with a practical lean toward web applications and adjacent services. Projects begin with scoping and solution design, then move into implementation with QA and release support on the same track. Robustness and security are explicit goals, so features land without brittle workarounds or manual bridges between systems. Interoperability is handled early through APIs and connectors. 

The delivery model is flexible enough to cover greenfield builds and modernization of live systems. Where the client relies on CRM or ERP tools, the build plan accounts for those dependencies rather than treating them as late-stage surprises. Cloud migration and managed environments are available when infrastructure needs a refresh alongside the application itself. 

After go-live, attention shifts to measurable improvements – performance passes, targeted feature releases, and maintenance that keeps the platform steady under real usage. Governance remains consistent, which reduces context switching between internal and outsourced contributors. The result is a steady cadence of delivery instead of large, risky drop-offs. 

Standout qualities:

• Focus on custom web apps with security and robustness in scope
• Integration-first mindset for predictable data exchange
• Cloud migration and managed environments available

Core offerings:

• Custom web application development under an outsourced model
• Architecture and solution design with scoped milestones
• API design, connectors, and system interoperability
• Application modernization and targeted feature expansion
• Quality assurance, automation, and release management
• Cloud setup, migration, and operations support

Contact Information:

• Website: www.pulsion.co.uk
• E-mail: info@pulsion.co.uk
• LinkedIn: www.linkedin.com/company/pulsion-technology
• Address: 5 Eagle Street, Craighall Business Park, Glasgow, G4 9XA
• Phone: +44 (0)141 352 2280

DataArt runs outsourced custom builds as one continuous track – discovery, solution design, implementation, and lifecycle care move together rather than hopping between silos. Work covers transactional systems and data-heavy products, with integration and modernization treated as core scope instead of side errands. Dedicated squads align with a client’s cadence, while QA, performance, security, and release management sit inside the same stream to keep deployments predictable. Cloud engineering shows up where it’s needed, not as an afterthought, which helps features travel from plan to production without detours. 

What stands out:

• Full-cycle custom engineering with QA and release practices embedded
• Modernization and system integration positioned as first-class scope
• Dedicated squads that plug into client ceremonies and roadmaps
• Cloud and data capabilities available within the same delivery lane

Service line up:

• Custom application design and development under an outsourced model
• Dedicated development teams and managed delivery squads
• API engineering, platform interoperability, and system integration
• Legacy modernization, refactoring, and re-platforming
• Quality assurance, automation, and release management
• Cloud architecture, migration, and environment operations

Contact Information:

• Website: www.dataart.com
• E-mail: hr-uk@dataart.com
• Facebook: www.facebook.com/DataArt
• Twitter: x.com/DataArt
• LinkedIn: www.linkedin.com/company/dataart
• Address: 55 King William Street, 3rd floor, London, EC4R 9AD
• Phone: +44 (0) 20 7099 9464

Ciklum frames outsourced custom development around flexible engagement models that map to different needs. Options include dedicated teams, project-based delivery, and augmentation, with pricing set up for fixed scope, time-and-materials, or outcomes when that makes sense. Product engineering spans web and mobile with discovery and architecture leading into iterative delivery, so scope stays visible while features ship. Integration and security considerations are handled inside standard release discipline, not bolted on at the end. 

Execution aims for a steady release cadence backed by QA automation and DevOps practices. Interoperability is planned early via APIs and connectors to avoid fragile handoffs between systems. For teams that want closer overlap, nearshore setups keep collaboration hours aligned and cut overhead on routine communication. After go-live, work continues through incremental improvements shaped by usage patterns rather than risky big-bang drops. 

Why clients pick this partner:

• Engagement flexibility – dedicated teams, project delivery, or augmentation
• Architecture and discovery up front for clear scope and trade-offs
• QA and DevOps used to support frequent, low-risk releases
• Nearshore collaboration options to simplify day-to-day coordination

Delivery focus:

• Custom application engineering across web and mobile
• Dedicated teams integrated with client ceremonies and toolchains
• System integration, API design, and data workflows
• Application modernization, re-platforming, and performance work
• QA automation, test frameworks, and release readiness

Contact Information:

• Website: www.ciklum.com
• E-mail: hello@ciklum.com
• Facebook: www.facebook.com/ciklum
• LinkedIn: www.linkedin.com/company/ciklum
• Instagram: www.instagram.com/ciklum
• Address: 5th Floor Standon House, 21 Mansell Street, London, United Kingdom, E1 8AA