Before a human ever reads your CV, a machine scores it. Applicant Tracking Systems (ATS) are used by virtually every mid-to-large tech company in 2026, and they're the reason your application disappears into the void.
Here's how they work — and exactly which keywords you need.
How ATS filtering actually works
ATS systems parse your CV into structured data and score it against the job description. They look for:
- Exact keyword matches — "Kubernetes" and "K8s" may or may not be treated as the same thing
- Keyword density — how many required skills appear, and how often
- Section structure — whether your CV has recognizable sections (Experience, Education, Skills)
- Recency — recent roles are weighted more heavily
If your score falls below the threshold, your CV is rejected automatically. No human ever sees it.
The keywords Western tech companies filter for
Infrastructure & DevOps
- CI/CD, GitHub Actions, GitLab CI
- Docker, Kubernetes, Helm
- AWS (EC2, S3, Lambda, ECS, RDS), GCP, Azure
- Terraform, Infrastructure as Code (IaC)
- Monitoring: Datadog, Grafana, Prometheus, New Relic
Backend
- Microservices architecture
- REST API, GraphQL, gRPC
- Node.js, Python, Go, Java, Rust
- PostgreSQL, Redis, MongoDB, DynamoDB
- Message queues: Kafka, RabbitMQ, SQS
- Event-driven architecture
Frontend
- React, Next.js, TypeScript
- Performance optimization, Core Web Vitals
- Design systems, component libraries
- Accessibility (WCAG), responsive design
- State management (Redux, Zustand, TanStack Query)
Process & methodology
- Agile, Scrum, Kanban
- Code review, pull requests
- Technical documentation
- Cross-functional collaboration
- Stakeholder communication
The mistake most developers make
Listing technologies in a Skills section isn't enough. ATS systems also look for keywords in context — within your experience bullet points.
Bad: listing "Docker" in your skills section and never mentioning it again.
Good: "Containerized 12 microservices with Docker, reducing environment setup time from 2 hours to 5 minutes and eliminating 'works on my machine' deployment issues."
How to find the right keywords for any job
- Read the job description line by line. Highlight every technology, tool, methodology, and soft skill mentioned.
- Check the "requirements" and "nice to have" sections separately. Requirements are must-have keywords; nice-to-haves boost your score.
- Look at 3-5 similar job postings. Keywords that appear across multiple listings are the ones ATS systems are most likely to filter for.
- Use the exact phrasing. If they say "CI/CD pipelines," use "CI/CD pipelines" — not "continuous integration and deployment."
A real example
Job description says: "Experience with cloud-native applications on AWS, microservices architecture, and CI/CD pipelines."
Before (typical Eastern European CV):
Developed backend services and managed deployments
After (keyword-optimized):
Built cloud-native microservices on AWS (ECS, Lambda, RDS), implementing CI/CD pipelines via GitHub Actions that reduced deployment cycles from weekly to 4x daily
Same work. One gets past the ATS. The other doesn't.
Westernize does this analysis automatically — it compares your CV against any job description, flags every missing keyword, and rewrites your bullet points to include them naturally.