# ctiapps.pro > Scalable systems. Reliable infrastructure. Building voice platforms and scalable backends since 2006. ## Services - [VoIP / RTC](/services/voip-rtc/): Voice platform architecture, WebRTC, FreeSWITCH, Kamailio, Asterisk, AI voice agents - [DevOps](/services/devops/): CI/CD pipelines, GitHub Actions, Terraform, Kubernetes, Docker, cloud infrastructure - [Architecture](/services/architecture/): System design, API development, microservices, multi-language backend engineering - [Scaled Backends](/services/scaled-backends/): High-throughput systems, voice test automation, distributed infrastructure ## Contact - Email: hello@ctiapps.pro - Phone: +34 65 22 99 183 - Telegram: https://t.me/ctiapps --- # VoIP / RTC Designing and building voice platforms since 2006. From single-server PBX deployments to distributed systems handling thousands of concurrent calls across multiple countries. ## Voice Platforms Full-stack voice engineering across the three major open-source telephony engines: Asterisk, FreeSWITCH, and Kamailio. We build hosted PBX systems, cloud call centers, IVR platforms, and custom call routing infrastructure. Our platforms have served telecom operators, MVNOs, enterprise contact centers, and government institutions across 15+ countries. ## WebRTC & Real-Time Communications Browser-based calling, SIP-to-WebRTC gateways, and hybrid architectures connecting WebRTC clients to traditional telephony infrastructure. We've built push-to-talk systems for industrial environments, callback platforms delivering PSTN quality through VoIP UX, and multi-channel contact center solutions. ## Contact Centers & IVR Custom contact center platforms with ACD, queue management, per-customer IVR trees, visual drag-and-drop call flow builders, and supervisor dashboards. We've built CCaaS solutions from greenfield and scaled answering-service platforms from 40 agents to company-wide operations. ## AI-Powered Voice Integrating AI into voice workflows using LiveKit, Pipecat, and OpenAI Realtime API. Building agentic voice systems that connect to existing telephony infrastructure: Asterisk-to-AI bridges, intelligent IVR replacement, and real-time voice agents. ## Telecom Integration SIP trunking, DID provisioning, SS7 gateway integration, multi-IMSI SIM switching for roaming elimination, SMPP-based SMS gateways, and carrier interconnect. Experience with both cloud-native and embedded voice deployments, from ARM-based solar-powered edge devices to multi-server carrier-grade clusters. --- # DevOps Production infrastructure and CI/CD automation. We build the pipelines and platforms that let engineering teams ship faster and sleep better. ## CI/CD & Build Automation Designing reusable CI/CD frameworks, from single-repo setups to organization-wide workflow systems supporting 100+ repositories and 200+ developers. GitHub Actions, GitLab CI, and Jenkins. Automated testing, deployments, release management, security scanning, and compliance checks. We've cut build times by 4x and migrated entire engineering organizations between CI platforms. ## Infrastructure as Code Terraform, OpenTofu, and Ansible for reproducible, version-controlled infrastructure. Docker and Docker Compose for development environments, Docker Swarm and Kubernetes (EKS) for production orchestration. We containerize applications, design deployment strategies, and build the automation that makes rollbacks painless. ## Cloud & Hosting AWS (EKS, EC2, RDS, Lambda, Amplify), DigitalOcean, and OpenShift. From single-server deployments to multi-region architectures. We've migrated monolithic platforms to containerized microservices on EKS, reducing infrastructure costs by 35% while doubling deployment speed. ## Monitoring & Observability Prometheus, Grafana, and ELK Stack (Elasticsearch, Logstash, Kibana) for metrics, dashboards, alerting, and log aggregation. We build observability into CI/CD pipelines, tracking build metrics, failure analysis, and deployment health across the software delivery lifecycle. ## Migration & Modernization Legacy-to-modern migrations: VM-to-container, Jenkins-to-GitHub Actions, monolith-to-microservices, on-premise-to-cloud. We plan the migration path, execute the cutover, and document the process so your team can maintain it independently. --- # Architecture Backend systems and API architecture across Python, Go, Ruby, Crystal, Lua, and Node.js. We design for the problem at hand, choosing the right language and architecture for each component rather than forcing everything through one stack. ## API Design & Development REST APIs, webhook integrations, and service-to-service communication. OpenAPI/Swagger documentation. We've built billing integration APIs, CRM connectors, provisioning systems, and call control interfaces, all designed for reliability and clear contracts. ## Microservices & Decomposition Breaking monoliths into independently deployable services. We've decomposed large Rails applications into granular services, extracting collection, processing, notification, and worker components, while planning frontend migration strategies and database partitioning. The goal is always incremental migration with minimal downtime. ## Backend Development Production backend systems in Python, Go, Ruby (Rails, Grape), Crystal, Lua, and Bash. High-performance workers, queue consumers, real-time event processors, and API servers. We pick the right tool: Go for concurrency-heavy services, Python for AI integration and scripting, Ruby for rapid API development, Crystal for performance-critical workers. ## Database & Data Architecture PostgreSQL, MySQL, MongoDB, Redis. Schema design, query optimization, and large-scale migrations. We've executed multi-terabyte PostgreSQL migrations with under 10 minutes of downtime using incremental replication strategies. Redis and RabbitMQ for caching, pub/sub, and distributed messaging between services. ## Documentation & Handover Architecture Decision Records, technical specifications, and integration documentation. We deliver systems your team can understand, maintain, and extend, not black boxes that require ongoing dependency. --- # Scaled Backends Building systems that handle real production load: thousands of concurrent calls, hundreds of thousands of messages per day, and distributed infrastructure across multiple countries. ## High-Throughput Voice Systems Voice platforms handling 400–700 simultaneous calls per cluster with HA failover. Bulk dialers pushing 300 concurrent outbound calls per node with horizontal scaling. Push-to-talk systems designed for 2,000 concurrent users per node. We size, architect, and validate capacity before going live. ## Distributed Infrastructure Multi-server clustering with Asterisk, Kamailio SIP proxies for load distribution, and queue-based worker architectures using RabbitMQ and Redis. Platforms deployed across multiple regions and countries, from centralized cloud clusters to edge devices in remote locations. ## Voice Test Automation End-to-end voice testing infrastructure: automated SIP call generation with SIPp, IVR flow validation, audio quality measurement, and carrier-level testing across multiple countries. We've built distributed GSM test networks using local hardware in 14 markets, and designed test frameworks that reduced manual voice testing from days to hours. ## High-Volume Messaging SMS gateways processing 500,000+ messages per day across multiple carrier connections via HTTP REST and SMPP. Notification systems, bulk messaging platforms, and multi-channel delivery (voice, SMS, fax, WhatsApp) with unified APIs. ## Fraud Detection & Platform Security Real-time call pattern analysis, configurable threshold alerting, and automatic blocking of suspicious traffic. Toll fraud prevention for telecom operators and hosted PBX providers serving thousands of customers. SIP security hardening, access control, and VoIP-specific threat mitigation.