IELTS Evaluator
AI band scores for IELTS writing and speaking, live as a web app with paid plans.
Open the live app
RajkumarJayakumar
Cloud & Technology Architect at Cognizant
I turn legacy monoliths into cloud-native platforms on AWS, Azure and GCP, and I build AI products that run in production.
- 18+
- 8
- 5
- 2
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- 4
Architecture that ships, and keeps running
For 18 years I have taken software from requirements to production support — first as a developer, then as a technical lead, and since 2018 as an architect at Cognizant for clients including Pacific Life, The Hartford, Nike and Telstra.
My work is re-platforming: breaking outdated systems into secure Spring Boot microservices, automating the infrastructure with Terraform, and shipping through CI/CD with OAuth2, JWT and encryption built into the pipeline.
Outside client work I build and run my own products. Two AI evaluation platforms are live today, and the rest of this page shows how they, and the systems behind them, are put together.
Generative and agentic AI architecture
I design and implement Generative AI and agentic AI solutions for healthcare, built on agentic AI architecture, large language models and enterprise GenAI solution architecture.
Diabetes prediction and management
Agentic AI workflows and Generative AI analyse patient data to support diabetes risk prediction and deliver personalised health insights and recommendations. Intelligent orchestration, data integration and context-aware AI support clinical decision-making and patient engagement.
Breast cancer analysis and early detection
Deep learning and medical image analysis, combined with Generative AI, support breast cancer detection and diagnostic workflows. AI processing pipelines and orchestrated agents run the image analysis, generate contextual insights and assist clinicians in their assessment.
How I work
Strangler-fig modernisation, not big-bang rewrites
Legacy monoliths are broken into domain-aligned Spring Boot microservices on EKS, AKS or serverless, one capability at a time behind stable APIs, so the business keeps running through the migration.
Pacific Life's Quartz batch jobs moved to Lambda, EventBridge and SNS.
Infrastructure as code from day one
Every environment is declared in Terraform with remote state and promoted through CI/CD in Jenkins, Bamboo or Azure DevOps, so environments are reproducible, auditable and reviewed like application code.
Nike's SMx samples platform was provisioned on AWS entirely in Terraform.
Event-driven and asynchronous by design
APIs respond immediately and hand long-running work to queues and streams (SQS, SNS, RabbitMQ, Kafka), with dead-letter queues for failures and live progress over SSE or WebSockets, so load spikes are absorbed instead of timing out.
The ATS Résumé Validator runs its AI jobs over RabbitMQ with dead-letter queues and streams progress over SSE.
Secure, observable and recoverable from the first release
OAuth2 and JWT sign-in, encryption, rate limits, health probes, metrics and scripted rollback ship in the first release, not in a hardening phase before go-live.
The ATS Validator shipped with liveness and readiness probes, Prometheus metrics and a release script with rollback.
Generative and agentic AI in production
LLMs and agentic workflows run behind the same controls as any other service: schema-validated output, retries, authentication, rate limits and a measured cost per call, so AI features are dependable enough to charge for.
IELTS and TEF/TCF Evaluator are live with paid plans, and every ATS Validator response is checked against a versioned JSON Schema.
Spec-led delivery and architecture governance
Design specs, API and message contracts and architecture decision records come before code, and teams of up to 15 are led from requirements through to production support.
The ATS Validator was built from 41 written specs and implementation plans.
Eighteen (18+) years, from programmer to architect
Eight roles in India and Canada. Client programmes link to their case studies.
Cloud & Technology Architect
Cognizant Technology Solutions Canada, Halifax, Nova Scotia, Canada
Re-platforming legacy monoliths into cloud-native microservices on AWS and Azure for insurance and retail clients: Terraform automation, CI/CD with security built in, and generative-AI solutions for claims and contracts.
Technology Architect
Cognizant Technology Solutions, Chennai, India
Cloud and DevOps architect for Telstra programmes — invoicing microservices, automated platform verification, emergency-call retrieval and eSIM support — on ECS, EKS and Pivotal Cloud Foundry.
Technical Lead
Infinite Computer Solutions, Bengaluru, India
Led Java/J2EE delivery teams from requirements to production support, brought in Agile delivery, and configured application servers, databases and cloud servers on AWS and SIFY.
IT Analyst
Tata Consultancy Services, Chennai, India
Senior Software Engineer, contract
Teamware Solutions (Quantum Leap), Chennai, India
Senior Application Developer
Globus Medical India, Chennai, India
Three years on Globus Medical's customised ERP portal: the first on the Globus account as a Software Engineer with Korcomptenz Consultancy Services, then in-house from August 2011 as Senior Application Developer. Built enhancements to the portal, travelled to Belgium and Germany to demonstrate it to users and implement it on site, and configured the WebLogic Server and Oracle Database behind it.
Software Developer
Netizen Technologies, Chennai, India
Programmer
Goldmine Infotech, Madurai, India
Projects across web, mobile, desktop and AI
Client programmes, two live products and the systems I build on my own time. Each one opens into a case study with its architecture.
TEF/TCF Evaluator
AI feedback for the French TEF and TCF exams, mapped to CEFR levels A1 to C2. Live.
Open the live app
ATS Résumé Validator
Real-time résumé scoring against a job description, with country-specific rewrites.
Pacific Life
Moved Pacific Life's scheduled batch work from Quartz to serverless, and automated claims with OCR.
- Contract Management and MyAccount
Image Intelligence Studio
One studio for image forensics, OCR, background removal and metadata scrubbing.
Nike
Nike's apparel-samples process on AWS, provisioned entirely in Terraform with micro-frontends.
- SMx Samples Management
The Hartford
Took The Hartford's premium audits from paper to digital and moved bank validation behind an API.
- MyAccount and XactPay
Telstra
Four programmes as cloud and DevOps architect: invoicing, platform verification, 000 emergency calls and eSIM support.
- DS-Invoicing
- AVITA
- 000 Legacy Call Retrieval
- eSIM Help and Support
Face-Swap Studio
A web app around the open-source roop face-swap engine, with queued jobs and live progress.
Remote-First Photo and Video Viewer
A photo and video viewer for Android TV and Google TV, designed around the D-pad.
DupeClean Pro
A desktop app that finds duplicate photos, videos and documents and cleans them up with a full undo.
NeuroGolf 2026
Solving ARC-AGI puzzles with the smallest neural network that gets every example right.
MedVoice
A real-time voice triage assistant on Gemini Live, built for the Gemini Live Agent Challenge.
The stack, layer by layer
How deep I go at each layer of a system. The number on a skill is how many case studies on this site use it.
- Core, core skill
- Proficient, proficient
- Familiar, familiar
Client
- React, core skill, used in 9 case studies
- TypeScript, core skill, used in 5 case studies
- Tailwind CSS, proficient, used in 2 case studies
- Angular, proficient, used in 1 case study
- Vue, proficient, used in 1 case study
- Next.js, proficient
- Micro-frontends, proficient
Mobile & desktop
- Flutter, core skill, used in 3 case studies
- PyQt, proficient, used in 2 case studies
- Swift & SwiftUI, proficient, used in 1 case study
- Unity, familiar, used in 1 case study
- React Native, familiar
- Electron, familiar
Services
- Python, core skill, used in 9 case studies
- Java, core skill, used in 8 case studies
- Spring Boot, core skill, used in 8 case studies
- REST & WebSockets, core skill, used in 5 case studies
- Django & DRF, core skill, used in 4 case studies
- RabbitMQ, core skill, used in 2 case studies
- Hibernate & JPA, core skill, used in 1 case study
- Microservices, core skill
- FastAPI, proficient, used in 4 case studies
- Celery, proficient, used in 4 case studies
- Kafka, proficient, used in 2 case studies
- Node.js, proficient, used in 1 case study
Data
- PostgreSQL, core skill, used in 8 case studies
- Oracle, core skill, used in 2 case studies
- MySQL, core skill
- Redis, proficient, used in 6 case studies
- MongoDB, proficient
- Elasticsearch, familiar
AI
- OpenAI GPT-4 & Whisper, core skill, used in 5 case studies
- PyTorch, proficient, used in 2 case studies
- ONNX, proficient, used in 2 case studies
- OpenCV, proficient, used in 2 case studies
- Anthropic Claude API, proficient, used in 1 case study
- Gemini Live, proficient, used in 1 case study
- RAG & LangChain, proficient
- Agentic AI & agent orchestration, proficient
- Hugging Face Transformers, proficient
- Amazon Bedrock & SageMaker, familiar, used in 1 case study
- TensorFlow, familiar
Cloud platform
- AWS, core skill, used in 5 case studies
- Serverless (Lambda, EventBridge), core skill, used in 4 case studies
- Kubernetes (EKS, AKS), core skill, used in 2 case studies
- Azure, core skill
- GCP (Cloud Run, GKE), proficient, used in 1 case study
- OpenShift, proficient, used in 1 case study
- Pivotal Cloud Foundry, proficient, used in 1 case study
Infrastructure & delivery
- Docker, core skill, used in 4 case studies
- Jenkins, core skill, used in 4 case studies
- Terraform, core skill, used in 1 case study
- CloudFormation, proficient, used in 2 case studies
- Prometheus, proficient, used in 2 case studies
- Bamboo & Bitbucket Pipelines, proficient, used in 1 case study
- Azure DevOps, proficient
- Ansible, familiar
Across every layer
- OAuth2 & JWT, core skill
- Agile delivery, core skill
- Spec-driven, AI-assisted development, core skill
- Multi-tenancy & row-level security, proficient
- Six Sigma, proficient
Education and credentials
Education
Master of Computer Applications
Gandhigram Rural Institute, 2006 – 2009
B.Sc. Computer Science
Sree Sevugan Annamalai College, Devakottai, 2000 – 2003
Certifications
- Six Sigma Green Belt
- Verified International Academic Qualifications
Languages and travel
Tamil, English
Demonstrated and rolled out Globus Medical's ERP portal on site in Belgium and Germany.
Let's talk architecture
Open to architecture and technical-leadership conversations. Send a note about the role, the system or the problem, and I'll get back to you.
- rajkumar.jayakumar@rajutechie.com
- linkedin.com/in/rajujrk
- github.com/rajujrk
- Halifax, Nova Scotia, Canada