Dario Simonetti

Software Engineer – Backend and infrastructure

  • Specialised in designing and building well-tested distributed systems and APIs using Go and Java.
  • Experienced in the realms of infrastructure with technologies including AWS, Google Cloud, Docker, Kubernetes and Terraform.
  • Proficient in a variety of different databases including PostgreSQL, DynamoDB and Firestore
  • Expertise in adopting DevOps practices and principles to greatly increase development throughput and software reliability.
  • Experienced in taking projects and features from problem statements to productionalised solutions.
  • Good understanding of frontend principles, frameworks and technologies.

Key technical experience

RESTful and gRPC APIs development using Java + Spring and Go • infrastructure as code using Terraform • application containerisation using Docker, Kubernetes and ECS • automated testing methods and processes (TDD) • service mesh using Linkerd • CI/CD using Jenkins, Go CD and GitHub Actions • AWS (EC2, S3, ECS, EKS, RDS and others) • Google Cloud (Cloud Run, Cloud Functions, GCS, Firestore, BigQuery and others) • microservice architectures and distributed systems • NoSQL (MongoDB, DynamoDB and Firestore) • database design, optimisation and SQL querying • heuristic optimisation algorithms such as GA and ACO

Work experience

▼ Founder and Software Engineer, Hikely (London, United Kingdom and Locarno, Switzerland)

June 2020 - Present (3 years and 10 months, part-time)

Built an API and algorithm for generating and finding hikes in various countries across Europe. Hikes are generated using a heuristic algorithm (Ant Colony Optimization) built in Go, matching the user criteria (duration, steepness and starting point), prioritising pretty trails (nice viewpoints, waterfalls, etc.) and avoiding bad trails (industry, airports, etc.).

It has not yet been publicly launched. I work on this in my spare time and for a few months each year in between contracts.

▼ Founder and Software Consultant, Hexago Tech (London, United Kingdom and Locarno, Switzerland)

April 2020 - Present (4 years)

Worked as a contractor through my own software consultancy company. Latest clients and projects (detailed information will be provided upon request):

  • Built APIs and tools to automate workflows that used to be carried out by people, which used to be inefficient and error-prone. Go, Firestore, BigQuery, Terraform, Kubernetes, Google Cloud, GitHub Actions.
  • Set up CI/CD and infrastructure for a very small startup. Terraform, Google Cloud, GitHub Actions.
  • Implemented a brand new API from scratch plus its CI/CD pipeline and infrastructure. Go, Terraform, Google Cloud, GitHub Actions.
  • Implemented new features in various APIs of an existing microservice system. Go, Java, Terraform, AWS.

▼ Technology Director, Attest Technologies (London, United Kingdom)

June 2018 - March 2020 (1 year and 10 months)

Promoted to oversee the technology department, reporting to COO & Co-Founder.

  • Introduced architecture design principles & patterns: Empowering engineers to make architectural decisions autonomously, whilst improving consistency and streamlining the onboarding process. The principles and patterns aim to reduce time-to-market, enable scale (both team and systems) and allow easy access to data by building an event-driven architecture which utilises Event Sourcing, CQRS and Kafka.
  • Introduced and lead platform team: Adding value to other product teams by providing tools and processes that aim to increase their throughput and improve their software and systems reliability.
  • Line management: Managed up to 7 engineers and data scientists, responsible for their individual career growth and wellbeing.

Provided technical direction to up to 4 squads and 20 engineers • Improved observability and alerting with Prometheus, Alertmanager and Grafana • Managed a Kubernetes (K8s) cluster running on AWS EKS • Introduced, used and managed a Kafka cluster • Service mesh with Linkerd 2.0 • CI/CD with Jenkins 2 and GitHub Actions

▼ Head of Core Engineering, Attest Technologies (London, United Kingdom)

January 2016 - May 2018 (2 years and 5 months)

Joined as the second engineer, responsible for all backend and infrastructure.

  • Launched initial Attest product: Allowing clients to create surveys and receive responses within hours, empowering them to make decisions based on data from consumers. Product launch included the B2B side, allowing clients to launch surveys and see live results, and the B2C side, allowing respondents to answer surveys and receive rewards.
  • Lead design, development and delivery of key features: Starting from problem statement all the way to a production-ready solution.
  • Introduced several DevOps practices: Reducing time-to market and increased software reliability. This enabled all engineers to build, test and deploy software faster and more reliably whilst also reducing costs.

Designed systems architecture consisting of 10 web services • Introduced DevOps processes and practices to ensure team consistently delivered high-quality software • Developed RESTful and gRPC web APIs with Java + Spring and Go • Data persistence in PostgreSQL and DynamoDB • Database design, optimisation and SQL querying • Test Driven Development (TDD) • Infrastructure as Code with Terraform • Containerisation with Docker and AWS ECS • Service mesh with Linkerd • CI/CD with Jenkins 2

▼ Meetup Organiser (voluntary), London Microservices Meetup (London, United Kingdom)

July 2017 - April 2022 (4 years and 10 months)

Organised monthly meetups about microservices and distributed systems. The meetup had about 5,000 members and events attract between 90 and 120 attendees. I supported speakers to source and refine ideas as well as providing guidance on individual presentations.

▼ Java/Scala Team Lead, OVO Energy (London, United Kingdom)

October 2014 - November 2015 (1 year and 2 months)
  • PAYG+: Led the development of PAYG+ (now Boost)—the first product in the UK enabling pre-pay energy customers to top up their utility meters online. The product was featured in Wired UK, The Sun and Tech News Europe, was placed at the centre of OVO's spring advertising campaign, and since launching in January 2015 has acquired over 25k customers in 10 months. Winner of 'Mobile Innovation' and 'Pioneering Tech' at New Thinking Awards 2016
  • Onboarding Timeline: Led the development of a product that supports PAYG customers in the 4-10 weeks period before the energy supply starts. The product saved money by reducing propensity to contact and operations overhead and reduced brand damage given the improved user experience. Part of the logic is now being adopted by 3 other teams.
  • Smart Meter Booking: Most recently led the development of OVO's smart meter booking product, preventing 35% of customers from signing up for a product they actually can't have and allowing the remaining 65% to manage their smart meter installation appointment online instead of having someone in operation call each one of the new customers.

Lead a team of a total of 6 developers • Designed systems architecture consisting of 7 microservices • Introduced processes and standards to ensure team consistently delivered high-quality software • Implemented different types of tools to ensure service management could monitor systems, get accidents alerts and do some basic troubleshooting in case of accidents • Developed RESTful Scala web services with Spray • Front end development in AngularJS 1 • Data persistence in NoSQL database (MongoDB) • Caching in Redis • Test Driven Development (TDD) • Continuous deployment with Go CD and configuration management with Chef

▼ Java/Scala Developer, Mylo (part of OVO Group, London, United Kingdom)

October 2013 - October 2014 (1 year and 1 month)

Development of Mylo, a mobile and web app for house sharers to manage bills online.

Developed RESTful Java web services with Dropwizard (Jetty + Jersey + Jackson) and Spring • Highly scalable Akka actor system (built in Scala) to fetch information from different third parties • Data persistence in SQL database (MySQL) • Test Driven Development (TDD) • Continuous integration with Jenkins and configuration management with Chef

▼ Java Developer, OVO Energy (London, United Kingdom)

March 2013 - October 2013 (8 months)

Joined as the second engineer. Development of My Ovo 2.0, the new OVO Energy customer portal. Worked under very tight deadlines to ensure go-live before 100,000 customers needed to renew the contract. Doubled the renewals conversion and halved the renewals propensity to contact.

Developed RESTful Java web services with Dropwizard (Jetty + Jersey + Jackson) and Spring • Data persistence in NoSQL database (MongoDB) • Test Driven Development (TDD) • Communication with third party system through SOAP, with caching strategies due to system slowness • Continuous integration with Jenkins and configuration management with Chef

▼ Java Developer, MintTwist (London, United Kingdom)

October 2011 - March 2013 (1 year and 5 months)

Development of the social bingo website m8tsbingo.com (acquired by Bingo Palace) • Development of a genetic algorithm to create the schedule for networking events organized by The Meeting Space (www.themeetingsspace.com) • Development of an app for iPhone, iPad, Android and BlackBerry using Cordova (formerly PhoneGap)

▼ Web Developer, MintTwist (London, United Kingdom)

November 2010 - October 2011 (1 year)

Development of the A.S. Watson HR extranet • Development of the Wire Mesh Fabrications e-commerce website wiremeshfabs.co.uk • Development of a custom PHP CMS used across several teams • Support to dozens of existing websites including shots.net, minttwist.com, kaba.ch, cbre.co.uk, plan-itinteriors.com and about 25 others

▼ Computer Science Apprentice, Schindler Group (Locarno, Switzerland)

September 2003 - August 2007 (4 years)

Development of software for the interpretation and graphical visualization of a log file. The software is able to read a lift log file and reproduce graphically its movements (as well as doors, lights, buttons, displays etc.) • Development of a software to customise audio ads used when the elevator reaches a floor • Used Java for all the software development.

Education

MSc in Software Engineering

University of Oxford (Oxford, United Kingdom)

January 2012 - December 2017 (part-time)

Distinction

BSc in Computer Science

SUPSI (Manno, Switzerland)

September 2007 - September 2010

Average grade of 93.6%

Apprenticeship in Computer Science

SPAI (Locarno, Switzerland)

September 2003 - August 2007

Best apprenticeship project in Switzerland

Key achievements

  • Led the development of the Attest platform, helping the company scale from 2 to 20 engineers, from 6 to 100 employees and from £0 to multi-million annual recurring revenue
  • Graduated with Distinction in 2017 in part-time MSc in Software Engineering at the University of Oxford
  • Led the development of OVO Energy PAYG+ (now Boost) – the first product in the UK enabling pre-pay energy customers to top up their utility meters online
  • Finished BSc in Computer Science in 2010 with an average grade of 93.6%
  • Awarded best individual apprenticeship project in Computer Science in Switzerland in 2007 amongst approximately 1,800 other projects