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Publicly listed on BSE · ISO 27001 & SOC 2 Type II certified
Publicly listed on BSE · ISO 27001 & SOC 2 Type II certified
API Systems Engineering
Unify applications, data, services, gateways, and cloud infrastructure through accountable API engineering. Our senior engineers apply approved AI tools while owning architecture, security, quality, and production outcomes.
Select the closest requirement to identify the right starting point.
Recommended:
API Strategy Workshop
Define consumers, contracts, data flows, security controls, ownership, and a phased API roadmap.
Get StartedAPI Engineering Built Around Outcomes
APIs connect applications, data, cloud platforms, partners, devices, and AI services. Every connection must work reliably in production today.
As an API development company, we help teams move from API strategy and architecture through delivery, modernization, and managed operations, with defined ownership across the API lifecycle.
Best Fit
Invest when release delays, brittle interfaces, security gaps, unclear ownership, or limited capacity constrain delivery.
Replace brittle endpoints when legacy debt slows releases, adds risk, and hides service health or ownership.
Connect systems when slow handoffs, duplicate data, and fragile point-to-point integrations disrupt operations.
Use reusable API contracts when product teams wait on shared systems, unclear interfaces, or delayed handoffs.
Establish API safeguards where access, versions, policies, audit evidence, or service ownership are inconsistent.
Improve services when traffic growth, hidden failures, latency, or weak recovery starts affecting users.
Standardize APIs as onboarding slows, credentials drift, schemas break, or partner support work grows.
Replace brittle endpoints when legacy debt slows releases, adds risk, and hides service health or ownership.
Connect systems when slow handoffs, duplicate data, and fragile point-to-point integrations disrupt operations.
Business Outcomes
As an API development company, we tie API engineering decisions to observable improvements in release flow, service reliability, integration effort, and operational control.
Reduce release delays with reusable contracts, automated tests, approvals, and repeatable API delivery controls.
Core Capabilities
Our custom API development services cover strategy, integration engineering, modernization, security, testing, governance, and production operations.
Our API consulting services turn goals, consumer needs, constraints, and delivery priorities into an agreed API roadmap.
Our custom API development services cover secure interfaces for products, data, workflows, and enterprise systems.
We deliver GraphQL API development and gRPC around consumer needs, payloads, latency, compatibility, and operations.
Our third-party API integration services connect cloud platforms, partners, data, AI services, and infrastructure.
We implement API management solutions for traffic policies, access, analytics, quotas, versioning, and onboarding.
We secure exposed APIs through threat-aware design, identity controls, encryption, policy enforcement, and testing.
We test functionality, contracts, security, resilience, and load while exposing service health, errors, and usage.
We modernize brittle APIs through staged migration, compatibility planning, governance, documentation, and retirement.
Our API consulting services turn goals, consumer needs, constraints, and delivery priorities into an agreed API roadmap.
Our custom API development services cover secure interfaces for products, data, workflows, and enterprise systems.
AI-Enabled API Engineering
AI-enabled delivery uses approved tools to assist planning, engineering, testing, and documentation. It is separate from integrating AI services into client systems.
We define approved tools, data-access boundaries, repository permissions, logging requirements, and human-review checkpoints for each engagement.
We use AI to structure requirements, map API workflows, and compare options before expert review and approval.
We use AI for workflow scaffolding and refactoring while engineers carefully review every production change.
We use AI to generate edge cases, API checks, and failure scenarios that strengthen overall validation coverage.
Delivery Process
01
We assess API risks, consumers, dependencies, and priorities, then agree on recommended next steps.
02
We design and document the API architecture, contracts, environments, controls, and service ownership for approval.
03
We deliver working APIs, integrations, tests, platforms, and operational controls for review.
04
We report test results for security, resilience, load, and recovery before approval.
05
We execute an approved release plan with rollback, monitoring, ownership and security checks.
06
We review service health, incidents, SLO results, and an approved API improvement backlog with leaders.
01
We assess API risks, consumers, dependencies, and priorities, then agree on recommended next steps.
See why businesses continue to choose Capital Numbers
Client StoryEngagement Models
Each API engagement model defines ownership, onboarding, delivery cadence, knowledge transfer, scope, timelines, and long-term service continuity.
Technology Expertise
Technology decisions reflect your consumers, system landscape, data flows, interaction patterns, traffic volumes, security requirements, and long-term operating priorities.
Industries We Serve
We design industry APIs around workflows, regulated data, access roles, system boundaries, and operating controls.
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We connect payments, banking, insurance, identity, and risk systems through APIs, transaction monitoring, and audit-ready controls.
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We create backend APIs for authentication, profiles, content, transactions, notifications, real-time features, and multichannel experiences for healthcare facilities.
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We connect commerce platforms, payments, inventory, CRM, identity, and analytics systems through secure APIs and governed data flows.
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We connect energy management, IoT, billing, grid, forecasting, and analytics systems through secure APIs and traceable data flows.
We connect payments, banking, insurance, identity, and risk systems through APIs, transaction monitoring, and audit-ready controls.
The Capital Numbers Advantage
We deliver accountable API engineering, governance, and continuity for complex integration environments.
BSE-listed company with corporate oversight.
SOC 2 Type II, ISO 9001, and ISO 27001 compliance guide secure delivery.
API, cloud, data, AI, QA, security, and DevOps experts form one team.
Named owners, release gates, logs, and escalation paths keep API delivery on course.
Choose delivery models aligned with your API roadmap.
Access 600+ in-house professionals across engineering.
BSE-listed company with corporate oversight.
SOC 2 Type II, ISO 9001, and ISO 27001 compliance guide secure delivery.
Explore expert insights on software architecture, modern development frameworks, AI-assisted engineering, application modernization, DevOps, testing, and scalable software delivery.
Share your API stack, goals, and priorities. On the first call, we recommend an API Readiness Assessment, implementation services, or managed support.
Replace brittle endpoints when legacy debt slows releases, adds risk, and hides service health or ownership.
Connect systems when slow handoffs, duplicate data, and fragile point-to-point integrations disrupt operations.
Use reusable API contracts when product teams wait on shared systems, unclear interfaces, or delayed handoffs.
Establish API safeguards where access, versions, policies, audit evidence, or service ownership are inconsistent.
Improve services when traffic growth, hidden failures, latency, or weak recovery starts affecting users.
Standardize APIs as onboarding slows, credentials drift, schemas break, or partner support work grows.
Cut down failed handoffs with reliable connections across applications, cloud services, and partners.
Make service health, dependencies, failures, usage, latency, and ownership visible through telemetry.
Reduce API risk through identity, encryption, policy controls, audits, and ownership.
Lower integration effort by reusing contracts, automating exchanges, and retiring connections.
Prepare for audits with named owners, tracked approvals, enforced policies, and documented controls.
Our API consulting services turn goals, consumer needs, constraints, and delivery priorities into an agreed API roadmap.
Our custom API development services cover secure interfaces for products, data, workflows, and enterprise systems.
We deliver GraphQL API development and gRPC around consumer needs, payloads, latency, compatibility, and operations.
Our third-party API integration services connect cloud platforms, partners, data, AI services, and infrastructure.
We implement API management solutions for traffic policies, access, analytics, quotas, versioning, and onboarding.
We secure exposed APIs through threat-aware design, identity controls, encryption, policy enforcement, and testing.
We test functionality, contracts, security, resilience, and load while exposing service health, errors, and usage.
We modernize brittle APIs through staged migration, compatibility planning, governance, documentation, and retirement.
We use AI to compare schemas, review mappings, and surface dependencies before engineers finalize integrations.
We use AI to draft API architecture notes, references, integration guides, runbooks, and release records.
We keep AI within approved data controls, peer review, security checks, and established delivery processes.
We follow a controlled API process with clear outputs and approval gates from assessment through ongoing operations.
Capital Numbers delivered third-party video API and VOD backend integrations for our mobile and web applications, completing the entire product within three months.
Ryan Davies
Managing Director, Like Media Group
Capital Numbers integrated our scheduling platform with our EMR and payment gateway APIs, increasing new patient numbers by 50–60% and cutting paperwork in half.
Vikas Malik
CEO, Wonder Years Psychiatric Services PLLC
Capital Numbers supports our ongoing API development with well-managed sprints, efficient ticket handling, thorough code reviews, and clear, responsive communication.
Jason Montoya
CEO, Payment Approved
Capital Numbers delivered third-party video API and VOD backend integrations for our mobile and web applications, completing the entire product within three months.
Ryan Davies
Managing Director, Like Media Group
Capital Numbers integrated our scheduling platform with our EMR and payment gateway APIs, increasing new patient numbers by 50–60% and cutting paperwork in half.
Vikas Malik
CEO, Wonder Years Psychiatric Services PLLC
Capital Numbers supports our ongoing API development with well-managed sprints, efficient ticket handling, thorough code reviews, and clear, responsive communication.
Jason Montoya
CEO, Payment Approved
Add API specialists with client-led ownership, onboarding, shared oversight, and regular knowledge transfer.
Best when:
You have technical leadership but need specialist API capacity.
GraphQL
AWS
Azure
Google CloudApigeeAzure API ManagementMuleSoft
PostgreSQL
MongoDB
Redis
MySQLApache KafkaWebhooksqueues
LangGraph
CrewAI
Semantic Kernel
Microsoft Agent Framework
OpenAIClaudeGeminiLlamaapproved model APIs
Docker
KubernetesTerraform
GitHub Actions
GitLab CI/CD
Jenkins
OAUTH 2.0OpenID ConnectSSO
Prometheus
GrafanaOpenTelemetryBSE-listed company with corporate oversight.
SOC 2 Type II, ISO 9001, and ISO 27001 compliance guide secure delivery.
API, cloud, data, AI, QA, security, and DevOps experts form one team.
Named owners, release gates, logs, and escalation paths keep API delivery on course.
Choose delivery models aligned with your API roadmap.
Access 600+ in-house professionals across engineering.
API development creates or updates secure interfaces, contracts, and service logic. API integration links them to applications, data, cloud services, or partners. End-to-end delivery can cover both, plus testing, monitoring, documentation, and governance.
Cost depends on functionality, architecture, protocols, integrations, data transformation, security requirements, and team composition. Capital Numbers begins with structured discovery to recommend a realistic roadmap and commercial estimate.
Timelines depend on interface complexity, existing systems, data readiness, security controls, documentation, migration requirements, and release strategy. Focused services can be delivered safely in phases, while broader transformations require a staged roadmap.
AI service integration connects models or AI platforms to your product. AI-enabled delivery uses AI tools to assist engineers who remain accountable.
We apply controlled access, secure development practices, encryption, code review, testing, audit trails, and formal production governance. Our delivery practices are SOC 2 Type II compliant, ISO 27001-compliant, and ISO 9001 aligned.
Ownership is defined in the project agreement. Typically, clients receive the custom source code and project IP created for the engagement, while third-party tools, open-source components, and pre-existing assets remain under their applicable existing licenses.
Yes. Our post-launch support covers monitoring, performance improvements, security updates, dependency maintenance, feature delivery, cloud optimization, documentation, and phased modernization based on the agreed support scope.
Publicly Listed
Technology Company
600+
Engineering Professionals
14+ Years
of Enterprise Delivery Experience
SOC 2 Type II, ISO 9001, ISO 270001
Certified
500+ Client Reviews
Across Global Platforms
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Expert guidance you can trust. No pitch, just expert solutions.
Trusted By Global Brands, Growth Companies, And Enterprise Teams
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CNBC TV-18 Most Trusted Brands India 2021
The Manifest - Most Reviewed Software Developers 2024
Financial Times - High-Growth Companies Asia-Pacific 2024
ET NOW - Best Tech Brands 2024
TIMES - Business Awards 2025 - Excellence in AI Solutions
ET Edge - Best Tech Brands 2025
NASSCOM - SME Inspire 2025 - Growth Leadership in Tech Services
ET NOW - Best Brands 2025
Clutch - Global Winner 2026
CNBC TV-18 Most Trusted Brands India 2021
The Manifest - Most Reviewed Software Developers 2024
Financial Times - High-Growth Companies Asia-Pacific 2024
ET NOW - Best Tech Brands 2024
TIMES - Business Awards 2025 - Excellence in AI Solutions
ET Edge - Best Tech Brands 2025
NASSCOM - SME Inspire 2025 - Growth Leadership in Tech Services
ET NOW - Best Brands 2025
Clutch - Global Winner 2026
CNBC TV-18 Most Trusted Brands India 2021
The Manifest - Most Reviewed Software Developers 2024
Financial Times - High-Growth Companies Asia-Pacific 2024
ET NOW - Best Tech Brands 2024
TIMES - Business Awards 2025 - Excellence in AI Solutions
ET Edge - Best Tech Brands 2025
NASSCOM - SME Inspire 2025 - Growth Leadership in Tech Services
ET NOW - Best Brands 2025
Clutch - Global Winner 2026
CNBC TV-18 Most Trusted Brands India 2021
The Manifest - Most Reviewed Software Developers 2024
Financial Times - High-Growth Companies Asia-Pacific 2024
ET NOW - Best Tech Brands 2024
TIMES - Business Awards 2025 - Excellence in AI Solutions
ET Edge - Best Tech Brands 2025
NASSCOM - SME Inspire 2025 - Growth Leadership in Tech Services
ET NOW - Best Brands 2025
Clutch - Global Winner 2026
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Laravel
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React
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React.js
D3.js
Pandas
Scikit-learn
