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Matthias Isler

Fractional CTO (Principal Engineer / Technical Architect)

Matthias Isler
Zürich, Switzerland

Experience

Jun 2022 - Present
3 years 9 months

Fractional CTO (Principal Engineer / Technical Architect)

  • Designed large-scale systems and APIs serving thousands of concurrent users.
  • Refactored a 650k-LOC monolith and led full AWS migration for stable performance.
  • Introduced SLO-based observability, improving reliability and recovery flow.
  • Optimised cloud and databases, achieving significant cost and latency reduction.
  • Delivered LLM, RAG, and document-automation pipelines adopted in production.
Apr 2021 - May 2024
3 years 2 months

Founder & CTO (AI/ML Engineer / Lead Engineer)

AureaTauri

  • Implemented XGBoost and ensemble models with faster, more accurate inference.
  • Built real-time trading pipelines with automated feature engineering.
  • Created full ML stack with warehouse, experiments, and CI/CD automation.
  • Scaled distributed GPU training 10× faster across AWS and GCP.
  • Ensured stable live operations with >50M real-market trading turnover.
Mar 2017 - Dec 2024
7 years 10 months

Co-Founder & CTO (Principal Engineer / Lead Architect)

GetYourLawyer

  • Designed a secure multi-tenant architecture with strong isolation and failover.
  • Developed matching and workflow engines for high-volume legal case routing.
  • Built AI agents, reducing paralegal workload by 80–90% and speeding turnaround.
  • Established CI/CD, testing, and observability enabling >99.9% uptime.
  • Mentored engineers, shaped coding standards, and led technical audits.
Feb 2014 - Nov 2018
4 years 10 months

CTO (Lead Engineer / System Architect)

Staffcloud

  • Directed full rewrite to modular multi-tenant SaaS with predictable latency.
  • Delivered enterprise APIs and integrations for large-scale deployments.
  • Introduced CI/CD and testing automation, cutting releases from weeks to hours.
  • Set up and managed a nearshoring engineering hub in Romania.
  • Mentored engineers and raised engineering standards company-wide.
Mar 2012 - Feb 2014
2 years

Lead Developer

Rad-Termin.ch

  • Designed scalable backend and modular frontend for multi-country networks.
  • Built a PHP framework (Zend-inspired) standardising the product suite.
  • Optimised DB and caching layers for faster API and page response times.
  • Established coding standards and release processes adopted firm-wide.
Jan 2005 - Dec 2012
8 years

Software Engineer - Various

  • Created a custom CMS framework that accelerated agency delivery.
  • Delivered production systems using PHP, JavaScript, and SQL.
  • Sold first commercial app implementation in high school; start of professional career.

Industries Experience

See where this freelancer has spent most of their professional time. Longer bars indicate deeper hands-on experience, while shorter ones reflect targeted or project-based work.

Experienced in Information Technology (14 years), Professional Services (8 years), Advertising (8 years), and Banking and Finance (3 years).

Information Technology
Professional Services
Advertising
Banking and Finance

Business Areas Experience

The graph below provides a cumulative view of the freelancer's experience across multiple business areas, calculated from completed and active engagements. It highlights the areas where the freelancer has most frequently contributed to planning, execution, and delivery of business outcomes.

Experienced in Information Technology (21 years), Product Development (21 years), and Quality Assurance (8 years).

Information Technology
Product Development
Quality Assurance

Summary

Senior engineer and architect with two decades of experience designing and scaling distributed systems, SaaS platforms, and AI/ML-driven architectures. Brings strong system design leadership and hands-on depth across Python/PHP/JS ecosystems, cloud infrastructure, and data-intensive workloads. Known for driving architectural clarity and raising engineering standards across teams.

  • Refactored a 650k-LOC monolith and led full cloud migration to a stable, scalable architecture.
  • Designed multi-tenant, high-throughput systems serving thousands of concurrent users.
  • Built LLM/RAG and automation pipelines adopted in production across several products.
  • Created ML trading infrastructure powering >50M live-market turnover.
  • Scaled distributed GPU training systems, achieving 10× faster experimentation cycles.
  • Delivered APIs, data models, and platform architecture used across multiple teams.
  • Led large-scale rewrites to modern microservice and event-driven architectures.
  • Raised engineering standards through design reviews, mentoring, and architectural guidance.

Skills

Architecture & Design

  • System Design
  • Software Architecture
  • Data Modelling
  • Distributed Systems
  • Microservices
  • Event-driven Architecture
  • Domain-driven Design (Ddd)
  • Multi-tenant Saas
  • Serverless
  • Cloud Architecture
  • High-availability
  • Api Design (Rest, Grpc, Graphql)
  • Scalability & Performance Engineering
  • Technical Debt Management
  • Large-scale Refactoring
  • Automation
  • Rfcs/adrs
  • Design Reviews
  • Code Reviews
  • Requirements Engineering

Technology Leadership & Collaboration

  • Technology Strategy
  • Architecture Governance
  • Okrs & Kpis
  • Project Management
  • Cost Optimization
  • Agile / Lean (Scrum, Kanban)
  • Interviewing & Hiring
  • Mentorship & Coaching
  • Cross-functional Collaboration
  • Async Communication

Ai & Machine Learning

  • Ai Integration
  • Applied Ml
  • Large Language Models (Llm)
  • Generative Ai
  • Retrieval-augmented Generation (Rag)
  • Multi-agent Systems
  • Llm Agents
  • Prompt Engineering
  • Langchain
  • Langgraph
  • Fine-tuning
  • Feature Engineering
  • Deep Learning (Pytorch, Tensorflow)
  • Xgboost
  • Scikit-learn
  • Mlops
  • Model Development, Evaluation & Monitoring

Cloud, Devops & Reliability

  • Cloud Transformation
  • Aws
  • Google Cloud Platform (Gcp)
  • Orchestration (K8s)
  • Containerisation
  • Infrastructure-as-code (Iac)
  • Serverless (Lambda, Cloud Functions)
  • Ci/cd
  • Vercel
  • Supabase
  • Nginx
  • N8n
  • Monitoring & Alerting
  • Observability
  • Apm
  • Opentelemetry
  • Site Reliability Engineering (Sre)
  • Performance Profiling

Data & Infrastructure

  • Relational Databases (Postgresql, Mysql)
  • Document Databases (Mongodb, Couchdb)
  • Key-value Stores (Redis, Dynamodb)
  • Graph Databases (Neo4j)
  • Vector Databases (Qdrant, Pinecone, Milvus)
  • Elasticsearch
  • Bigquery
  • Data Warehousing
  • Databricks
  • Apache Spark
  • Etl/elt
  • Airflow
  • Prefect
  • Streaming (Websockets)
  • Messaging & Queues (Rabbitmq, Sqs, Pub/sub)

Programming & Frameworks

  • Python
  • Php
  • Sql
  • Javascript
  • Typescript
  • Fastapi
  • Django
  • Laravel
  • Symfony
  • Node.js
  • Nestjs
  • React
  • Next.js
  • Vue.js

Security, Quality & Testing

  • Unit Testing
  • Integration Testing
  • E2e Testing
  • Test Automation
  • Secure Coding
  • Owasp
  • Authentication Management

Key Highlights

  • Managed 7-figure Budgets
  • Consulting, Management, And Entrepreneurial Experience
  • Deep Ai/ml Expertise

Languages

German
Native
English
Advanced
Spanish
Elementary
French
Elementary
Serbian
Elementary

Education

Oct 2007 - Jun 2011

SBW Neue Medien

Swiss Federal VET Diploma, Mediamatics Technician · Mediamatics Technician · Switzerland

Oct 2007 - Jun 2010

SBW

Swiss Federal Vocational Baccalaureate, Information & Communication · Information & Communication · Switzerland

University of Colorado Boulder

Master of Science, Artificial Intelligence · Artificial Intelligence · Boulder, United States

Profile

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Frequently asked questions

Do you have questions? Here you can find further information.

Where is Matthias based?

Matthias is based in Zürich, Switzerland and can operate in on-site, hybrid, and remote work models.

What languages does Matthias speak?

Matthias speaks the following languages: German (Native), English (Advanced), Spanish (Elementary), French (Elementary), Serbian (Elementary).

How many years of experience does Matthias have?

Matthias has at least 21 years of experience. During this time, Matthias has worked in at least 6 different roles and for 4 different companies. The average length of individual experience is 4 years and 6 months. Note that Matthias may not have shared all experience and actually has more experience.

What roles would Matthias be best suited for?

Based on recent experience, Matthias would be well-suited for roles such as: Fractional CTO (Principal Engineer / Technical Architect), Founder & CTO (AI/ML Engineer / Lead Engineer), Co-Founder & CTO (Principal Engineer / Lead Architect).

What is Matthias's latest experience?

Matthias's most recent position is Fractional CTO (Principal Engineer / Technical Architect).

What companies has Matthias worked for in recent years?

In recent years, Matthias has worked for AureaTauri and GetYourLawyer.

Which industries is Matthias most experienced in?

Matthias is most experienced in industries like Information Technology (IT), Advertising, and Professional Services. Matthias also has some experience in Banking and Finance.

Which business areas is Matthias most experienced in?

Matthias is most experienced in business areas like Information Technology (IT), Product Development, and Quality Assurance (QA).

Which industries has Matthias worked in recently?

Matthias has recently worked in industries like Information Technology (IT), Professional Services, and Banking and Finance.

Which business areas has Matthias worked in recently?

Matthias has recently worked in business areas like Information Technology (IT), Product Development, and Quality Assurance (QA).

What is Matthias's education?

Matthias holds a Master in Artificial Intelligence from University of Colorado Boulder.

What is the availability of Matthias?

Matthias is immediately available full-time for suitable projects.

What is the rate of Matthias?

Matthias's rate depends on the specific project requirements. Please use the Meet button on the profile to schedule a meeting and discuss the details.

How to hire Matthias?

To hire Matthias, click the Meet button on the profile to request a meeting and discuss your project needs.

Average rates for similar positions

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Market avg: 1100-1260 €
The rates shown represent the typical market range for freelancers in this position based on recent contracts on our platform.
Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.