Sam Mosios

Summary

Site Reliability and Platform Engineer with production experience across enterprise and early-stage environments, specializing in GitOps, CI/CD automation, Kubernetes, and end-to-end observability. Focuses on the trade-offs between security, reliability, scalability, and developer experience rather than optimizing any single axis in isolation. Currently pursuing an MSc in Distributed Systems at KTH to formalize the theory behind systems already built and shipped in production.

Work Experience

Site Reliability & Platform Engineer Oct 2025 – Present

Hyppe (early-stage startup)

Designed and delivered a five-stage infrastructure roadmap, migrating from Railway's push-to-deploy setup to a structured AWS environment with Terraform-managed IaC and per-environment promotion gates (dev → staging → production) across 2 repos.
Built reliable CI/CD pipelines for backend and frontend, enabling production releases in under 4 minutes for the backend and under 2 minutes for the frontend, with automated semantic versioning and changelog generation on every release.
Implemented OpenTelemetry instrumentation and 6 Grafana dashboards covering API performance, serverless infrastructure (Aurora Serverless v2, Fargate), and application logs, giving the team their first structured visibility into production system health.
Independently designed and built the entire infrastructure from scratch as the sole engineer on a 2-person team, establishing runbooks and deployment standards that de-risked the product's transition from prototype to production.

Site Reliability Engineer Jul 2024 – Jul 2025

Pfizer

Refactored and centralized copy-pasted CI/CD scripts into reusable, parameterized GitHub Actions workflows, standardizing release processes across 2 teams and ~40 repositories.
Extended and maintained GitOps infrastructure via Flux across non-prod and prod clusters, covering 60+ services and ensuring all infrastructure changes were version-controlled, reviewable, and auditable.
Administered 2 Kubernetes clusters (non-prod and prod), covering cluster networking, monitoring, GitOps management, and secrets administration.
Instrumented ~30 microservices with OpenTelemetry, enabling distributed tracing across service boundaries and reducing time-to-diagnosis during incidents.

Web GIS Developer Jun 2023 – May 2024

OMIKRON S.A.

Deployed a Dockerized pre-trained PyTorch model on AWS EC2, handling containerization, provisioning, and deployment configuration end-to-end.
Monitored dedicated and cloud server infrastructure using Grafana, establishing the team's first observability baseline.

Technical Skills

Cloud & IaC AWS, Terraform

Containers Docker, Kubernetes, AWS Fargate

CI/CD & GitOps GitHub Actions, Flux, semantic versioning

Observability OpenTelemetry, Grafana, distributed tracing

Security IAM, least-privilege design, secrets management, network segmentation

Reliability SLO/SLA design, incident runbooks, failure containment

Scripting Bash, Python, Go, JavaScript / TypeScript

Concepts Event-driven architecture, microservices, distributed systems

Education

MSc in Software Engineering of Distributed Systems Aug 2025 – Jun 2027

KTH Royal Institute of Technology, Stockholm, Sweden

Consensus protocols · CRDTs · Replicated state machines · Fault-tolerant system design · Distributed AI & Intelligent Agents · Modern Methods in Software Engineering · Networked Systems Security · Language-based Security · Software Safety & Security · Data Mining

BSc (Hons) in Computing Oct 2022 – Jun 2025

University of Greater Manchester, Thessaloniki, Greece

First-Class Honours · Dissertation: Leveraging MLOps and Continuous Learning for Predictive Analysis of Traffic Accidents in the UK ↗

Workshops Presented

Git It Together: Hands-on Git & GitHub , Pfizer Growth Gig

Git fundamentals, branching strategies, and collaborative workflows for engineering teams.

From Code to Cloud: Docker & Kubernetes Demystified , 1st Informatics Projects Exhibition, New York College Thessaloniki

Containerization concepts and Kubernetes architecture, aimed at developers new to cloud-native tooling.

When Computers Disagree: A Hands-on Intro to Distributed Systems , 2nd Informatics Projects Exhibition, New York College Thessaloniki

Consistency, consensus, and failure in distributed systems, made tangible through interactive examples.

Summary

Work Experience

Technical Skills

Education

Certifications

References

Workshops Presented

Languages