Kasper Vaus

01 / About

Building reliable systems
at communication scale

Backend-focused Software Engineer at Twilio with experience building scalable APIs, improving reliability, and optimizing performance for high-throughput communication systems.

Strong background in Java services on AWS, distributed workflow orchestration, infrastructure automation, and observability — with end-to-end ownership from design through production operations.

Location Tallinn, Estonia

Education B.Sc. Hardware Dev & Programming, TalTech

Languages English, Estonian, Russian

02 / Experience

Professional timeline

Sept 2024 — Present

Software Engineer (L2)

Twilio · Tallinn

Built and evolved backend APIs for Twilio Notifications covering device registration, application lifecycle, and recipient management with standardized error models and OpenAPI-aligned contracts.
Developed dynamic recipient segmentation for near real-time filtering, enabling downstream SMS, email, and push workflows to target audiences by attributes such as creation date and location.
Migrated critical workflows to Temporal, improving orchestration reliability, failure handling, and operational maintainability for distributed processes.
Built an automated Artillery-based end-to-end testing pipeline on Kubernetes, improving scalability, repeatability, and observability with Datadog dashboards and alerting.
Led development of a SpiceAI caching sidecar for a read-heavy internal service, reducing a key backend bottleneck and improving scalability for business-critical downstream systems.

Sept 2023 — Sept 2024

Software Engineer (L1)

Twilio · Tallinn

Delivered 25+ production APIs for a new internal communications platform, enabling scalable recipient management and integration across Twilio services.
Reworked database schema and query patterns — including pagination, indexing, and filtering strategies — cutting large-dataset lookup times from ~1.2s to 60ms.
Load-tested Twilio Notifications systems with Artillery to identify throughput limits and built custom Python tooling to automate test execution and scenario management.
Improved end-to-end test observability by migrating alerting into Datadog and automating dashboards and monitors with Terraform, reducing manual operational review effort.

Jun 2022 — Sept 2022

Software Engineer Intern

Twilio · Tallinn

Extended an internal automation tool for the Messaging organization, replacing manual runbook steps and standardizing recurring operational workflows.
Added business logic, test automation, and bug fixes to a production service while documenting improvements and proposing enhancements to improve team efficiency and code quality.

03 / Skills

Technical toolkit

Languages & Frameworks

Java Spring Boot Python JavaScript C PHP

Cloud & Infrastructure

AWS Kubernetes Docker Terraform Azure

Data & Messaging

DynamoDB Aurora RDS MySQL Apache Kafka SQS Elasticsearch

Observability & CI/CD

Datadog Prometheus Grafana CloudWatch Jenkins GitHub Actions

Tooling

Git Maven Gradle JUnit Mockito IntelliJ

04 / Projects

Selected work

Side projects and academic work across embedded systems, web development, and desktop applications.

Nutipistik

2023

Smart plug solution for intelligent electricity usage. Multi-component architecture spanning PHP, Python, C++, and JavaScript with hardware integration.