Peeter A.

Senior Full Stack Engineer

Tallinn, Estonia

Experience

Sep 2022 - Sep 2025
3 years 1 month
Netherlands

Senior Full Stack Engineer

Leviy a Zvoove Company

  • Designed a microservices-based SaaS platform with 12+ Python services (Django, FastAPI, AsyncIO), event sourcing, and gRPC, reducing client onboarding time from days to hours.
  • Developed a modular frontend system using React 18, Redux, TypeScript and Vite, incorporating GraphQL, Apollo Client, and Formik to streamline UI consistency and adaptability across applications.
  • Enhanced frontend performance and UX by adopting React Server Components, WebAssembly (WASM), Next.js SSR/ISR, and Tailwind CSS, improving Time to Interactive (TTI) and client satisfaction scores.
  • Built complex data ingestion and ETL flows with FastAPI, pandas, NumPy, SQLAlchemy, and Celery, automating validation and transformation of multi-GB Excel manifests into MySQL and DocumentDB.
  • Integrated OpenAI, Anthropic, and Google AI APIs with LangChain, LangGraph, and ADK, enabling seamless deployment of automated summarization, semantic search, and workflow assistance within core applications.
  • Deployed AI-driven predictive analytics models (PyTorch + FastAPI inference services) for customer behavior insights, integrating results into React dashboards and internal APIs.
  • Directed multi-region AWS infrastructure design (ECS, EKS, RDS, S3, CloudFront, Lambda) using Terraform and Crossplane, and automated CI/CD pipelines using Jenkins, GitLab CI, SonarQube, and Dockerized deployments.
  • Elevated overall product quality by enforcing comprehensive test automation across the stack with JUnit, Mockito, PyTest, Cypress, Jest, and Selenium, achieving code coverage and a substantial reduction in post-release defects.
  • Implemented advanced API security architecture, including rate limiting, robust input validation, and hardened JWT/OAuth2 token management, ensuring full SOC 2 and GDPR compliance.
  • Standardized external partner onboarding through comprehensive OpenAPI 3.0 specifications and Swagger documentation, reducing integration time by more than two-thirds.
  • Implemented DevOps workflows with GitHub Actions, Docker Compose, AWS Code Pipeline, and SonarQube, ensuring high test coverage and zero manual deployments.
  • Mentored and coached a distributed team of four engineers, conducting architecture reviews and knowledge sessions that tripled merge velocity and improved cross-team collaboration.
May 2018 - Aug 2022
4 years 4 months
Switzerland

Senior Full Stack Engineer

ATIS Software Factory

  • Directed the strategic decomposition of a large monolithic system into Django/FastAPI microservices, enabling independent deployments, accelerating release cycles, and reducing time to recovery.
  • Designed and deployed modular frontends using React 17, Angular 14 and Next.js, integrated via micro-frontend architecture to support feature isolation and CI.
  • Modernized legacy Angular apps by refactoring to React, introducing Zustand, React Hook Form, Storybook, and Cypress for component isolation and e2e testing.
  • Created a Node.js/Express notification microservice for WebSocket fan-out, decoupling push traffic from Python APIs and stabilizing delivery during spikes.
  • Engineered a multi-tenant SaaS platform using CosmosDB, SQL Server, and PostgreSQL, employing sharding, partitioning, and RBAC strategies to support 1M+ users with seamless scalability.
  • Engineered high-performance, real-time APIs using GraphQL, REST, gRPC, and WebSockets with CQRS patterns, message queues, Redis caching, and async Python to double throughput and reduce average response times.
  • Deployed a unified observability stack with Prometheus, Grafana, and ELK, introducing SLO-based dashboards and automated alerting to significantly improve fault isolation and accelerate recovery.
  • Implemented enterprise-grade SSO using OAuth2/JWT with fine-grained role-based access control, supporting 100 K+ users and achieving zero security incidents over 12 months.
  • Implemented DevOps workflows with GitHub Actions, Docker, AWS ECS, and SonarQube, ensuring high test coverage and zero manual deployments.
  • Integrated advanced CI/CD pipelines with infrastructure-as-code practices using Terraform and Kubernetes, automating environment provisioning and deployment workflows to minimize downtime and support rapid scaling.
Mar 2016 - Apr 2018
2 years 2 months
Germany

Full Stack Engineer

eXXcellent Solutions

  • Engineered high-performance single-page applications using React.js, Redux, SASS, and React Router, implementing SSR with Next.js and custom Express middleware, along with lazy loading and virtual DOM optimizations to achieve a 20% reduction in page load times.
  • Developed a centralized, reusable UI component library using Storybook, standardizing design implementation across teams and accelerating frontend delivery velocity.
  • Designed and implemented real-time advertising data pipelines with Flask, Celery, and Redis to process over 10 million events per day with sub-second latency.
  • Optimized PostgreSQL schema design and indexing, cutting complex query execution time and improving system responsiveness.
  • Established CI/CD pipelines with Jenkins and Git, introducing automated testing and continuous deployment practices that reduced release times from hours to minutes.
  • Implemented centralized logging and monitoring with the ELK stack and custom alerting rules, improving time to detect and resolve incidents.
  • Migrated legacy microservices to a container-based framework using Docker and Kubernetes, optimizing deployment workflows and enhancing scalability in high-volume SaaS applications.
  • Introduced automated end-to-end tests (Pytest and Selenium), ensuring high confidence in daily production releases and lowering defect escape rates.
  • Engineered serverless AWS Lambda services (Python and Node.js) with SQS/SNS, improving burst scalability and lowering infrastructure costs.
Oct 2012 - Mar 2016
3 years 6 months
Estonia

Full Stack Engineer

OIXIO IT

  • Developed a secure, scalable billing and messaging platform on Python, Node and PostgreSQL, integrating Stripe and Twilio to automate transactions and ensure reliable payment processing.
  • Engineered end-to-end automation of raw data extraction and staging by utilizing custom Python scripts and optimized SQL queries, streamlining the integration of source data into centralized analytics pipelines.
  • Designed and implemented a Python-based billing rules engine with exhaustive edge-case handling, reducing billing inaccuracies and ensuring consistent financial reconciliation.
  • developed traceable test flows using automated frameworks and scripting tools such as Cypress and Jest, meeting regulatory and audit requirements in collaboration with compliance and QA teams.
  • Automated GitLab CI/CD pipelines with Docker containers, reducing release time from one hour to ten minutes and enabling continuous delivery.
  • Engineered secure RESTful APIs and integrated third-party data sources to streamline care management workflows, reinforcing HIPAA compliance and supporting seamless data exchange between core platform modules.
  • Modernized legacy monolithic services by refactoring critical components into microservices using Python and Node.js, strengthening system reliability and enabling rapid horizontal scaling across cloud environments.

Summary

Senior Full Stack Engineer with 12+ years of experience architecting and scaling cloud-native, event-driven platforms. Brings deep expertise in Python (Django, FastAPI, Flask, Celery, pandas, NumPy) and Node.js (Express, NestJS, TypeScript), and extensive practice designing multi-region architectures across AWS, Azure, and GCP. Proficient in microservices, distributed data pipelines, and gRPC/GraphQL APIs, with a strong track record of delivering zero-downtime CI/CD and highly available systems. Experienced in SOC 2, GDPR, and HIPAA compliance, advanced security engineering, and in mentoring cross-functional teams to build scalable, maintainable, and cost-efficient solutions.

Languages

Estonian
Native
English
Advanced
German
Elementary
Dutch
Elementary

Education

Tallinn University of Technology

Bachelor's degree · Computer Science · Tallinn, Estonia

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