David Lozano Jarque Full stack software engineer: from scratch to production
Turning ideas into code is my passion: I've been developing software since I was in elementary school. First as a hobby, then as a freelance, and eventually in a company. Overall, my mission is to provide valuable contributions to great projects that can make a difference in their users' lifes
language Spanish (Native)
language Catalan (Native)
language English (Advanced)
Work
Vesto Senior Software Engineer (as freelancer)
date_range 2022-10-10 - Present
Backend. Lead direct batch buy feature to buy multiple stocks at once. Lead robustness planning to improve the app stability, focusing on gaining observability to push for data-driven decisions and automating processes to reduce customer support workload
Highlights
- Lead continuous proposals to improve company's processes, backend team side and company wide. Like pushing for technical refinements, differentiating between bugs an complaints, tracking estimations accuracy
- HTTP REST JSON APIs development using Ruby on Rails + dry-validation + OpenAPI
- Managing AWS infrastructure with Terraform: ELB, ECS + Fargate
- Added New Relic as observability tool
Koa Health (Telefónica Alpha) Senior Software Engineer
date_range 2020-03-01 - 2022-06-07
Full stack. Started as mid. Promoted to senior in 1st year's performance review. Owned several features implementations. Aligned with product, design, QA, DevOps, cybersec, research & other products' engineering teams. Lead & participated in squad's processes improvements
Highlights
- Several features owner like audio exercises, push notifications, therapist & patient messaging for the Mindset product
- HTTP REST JSON APIs development using Node.js + Typescript + OpenAPI
- Support DevOps team maintaining the backend app infrastructure: K8s + Helm + Terraform to manage AWS resources (API Gateway, ALB, Cognito, RDS). Datadog for observability
- Maintenance of GitHub Actions CI/CD pipelines
- Continuous proposals & contributions in projects' authZ/N: OAuth 2.1 / OIDC / SSO with 3rd party IdP federation via AWS Cognito. API Gateway auth. JWT tokens management
- Mobile app development for Android & iOS using Flutter 1/2 + Dart
- Web app development (SPA) using Angular 9+
BTC Assessors Full stack software engineer & DLT consultant
date_range 2018-06-01 - 2019-12-31
Lead software engineer for all company's projects. Blockchain / DLT consultant and researcher. Board member of the company's own cryptocurrency investment fund as technical advisor
Highlights
- Web backend RESTful APIs with OpenAPI, Spring Boot, Kotlin and Python
- Web frontend Material Design PWA with Angular 7 & 8, Polymer, Redux, Typescript, Javascript, SCSS and HTML5
- DevOps with Docker, GitLab CI/CD, TravisCI and Heroku
- Linux-based systems administration (Arch Linux, Debian, Ubuntu)
- Libraries for data verification in Typescript, Javascript and Kotlin
- Library for Bitcoin cryptocurrency's scripting in Python
- Software project management: 4+1 architecture, Domain driven design (DDD), Agile methodologies
SEAT Software Developer (freelance in internship)
date_range 2017-03-13 - 2017-06-19
Integration and adaptation of the IBC Biomechanics software within SEAT IT Systems for its internal biomechanical laboratory in the CARS center in the Martorell headquarters
Highlights
- Python 3.6 (using Anaconda)
- Desktop GUI using PyQt4/5
- SQLAlchemy
- MariaDB
Meditrauma IT Manager (as outsourced freelance)
date_range 2015-01-15 - 2018-06-01
Outsourced IT Systems and infrastructure accountable of the three company headquarters, performing typical systems administration tasks and IT consultancy
Highlights
- LAN and WLAN TCP/IP networks installation and management (including cibersecurity tasks such as traffic filtering)
- Servers installation and maintenance using Ubuntu and Microsoft Windows Server 2003/2012
- Database setup and maintenance using Borland BDE, Microsoft Access and Microsoft SQL Server 7/2008
- Network file sharing installation and maintenance (with permission management) using Samba protocol
- Network printer spool services installation and maintenance using Canon, HP, Epson printers
- Workstation installation and maintenance using Microsoft Windows 7/8/10 (also migrated old ones from XP) and setting up enterprise sofware including ofimatics and internal ERP customized software(s)
- Installation and maintenance of DICOM networks and services
- Installation and maintenance of point-of-sale devices
- Installation and maintenance of medical equipment hardware and services such as X-Ray machines and ECGs
- Installation and maintenance of laboral risk prevention devices like audiometers
IBC Biomechanics Software Engineer & IT Manager (as freelance)
date_range 2014-09-15 - 2018-06-01
Developed a biomechanics report generator app that takes user-designed templates and merges data from a collection of third-party applications to generate reports
Highlights
- Python 2.7 / 3.6 (using Anaconda framework)
- JavaSE 8 (using PyBluez to handle Bluetooth connections)
- Desktop GUI(s) using PyQt4/5
- Database applications using SQLAlchemy
Education
Universitat Oberta de Catalunya UOC Master's degree MISTIC (Cibersecurity)
- date_range 2017-09-20 - 2018-09-20
- grade Avg: 8.14/10, (3.38/4 GPA). Unfinished
Courses
- Digital Identity
- Legislation and Regulation
- Security vulnerabilities
- Networks' security
- Databases' security
Universitat Autònoma de Barcelona UAB University degree Computer Science Engineering
- date_range 2013-09-13 - 2017-06-20
- grade Cum laude, Avg: 8.86/10 (3.85/4 GPA)
Courses
- Algebra and Calculus
- Electricity and Electronics
- Computer Architecture
- Operating Systems
- Software Development
- Database Management (RDBMS and NoSQL)
- Agile Methodologies
- Computer Networks (Advanced)
- Distributed Systems
- Systems Administration
- Information and Security (Advanced)
- PKI
- Big Data
- Web Services
- DevOps
- Blockchain technology (Advanced)
- Bitcoin development (Advanced)
Institut de Mollet del Vallès High school Science and Technology
- date_range 2011-09-13 - 2013-06-01
- grade Cum laude, Avg: 9.76/10 (3.96 GPA)
Courses
- Catalan
- Spanish
- English
- Industrial technology
- Maths
- Physics
- Technical Design (and CAID)
- Enterpreneurship
- Internship (as computer technician)
Awards
2nd place at University degree's gamification program dEIC.UAB.cat
- calendar_today 2016-06-25
TOP Enginyeria is an engineering gamification program implemented in several engineering degrees that aims students to go further than classes with extra projects, competitions, challenges and games apart from traditional classes, awarding the best students with symbolic rewards and extra activities to motivate them in their studies and improve their rivailry to get the best performance possible
Projects
Vesto For Vesto 2022-10-10 - Present
- Senior software engineer
- Backend
Mobile app to introduce users to the world of financial investments. Allows to easily invest in US stock market with credit card or bizum. Focused for Spanish market. Worked on the backend side
Ruby on Rails 6
Sidekiq
REST API
OpenAPI
RSpec
PostgreSQL
Redis
Docker
GitHub Actions
Terraform
AWS (EC2, ECS, RDS, ELB, ElastiCache)
RedSys
New Relic
Slack
Mindset For Koa Health / Telefónica Alpha 2020-03-01 - 2022-06-07
- Senior software engineer
- Full stack
Mobile app for patients to treat depression using Cognitive Behavioral Therapy (CBT) exercises. Web app for therapists to track patients' progress
Flutter 1 & 2
Typescript
Node.js
Express
REST API
OpenAPI
Jest
PostgreSQL
Docker
GitHub Actions
Terraform
AWS (EKS, ALB, RDS, API Gateway, Cognito)
Datadog
Cowstamp For BTC Assessors 2019-07-29 - 2019-12-17
- Lead software engineer
- Full stack developer
Web SaaS app to create, issue and receive verifiable credentials digitally signed using blockchain technologies with a user-centric design. Uses a custom ad hoc library to canonize JSON-LD graphs
Angular 8
Typescript
PWA
REST API
OpenAPI
Spring Boot
Kotlin
Apache JMeter
JUnit 4
Liquibase
MongoDB
PostgreSQL
Gradle
JHipster
Docker
Heroku
GitLab CI/CD
Linux
Blockchain
Blockcerts
JSON-LD
Agile methodologies
Kowbucha For BTC Assessors 2019-11-14 - 2019-12-17
- Lead software engineer
- Frontend developer
Web app to allow an independent verification of Blockcerts verifiable credentials based upon users' trust decisions. Uses a companion NodeJS & browser Javascript library created ad hoc to perform the verifications.
Material Design
Angular 8
Typescript
PWA
Redux
Karma
Jasmine
Jest
Node.js
Rollup.js
npm
GitLab CI/CD
Karma
Jasmine
GitLab Pages
Blockchain
Bitcoin
Ethereum
Blockcerts
JSON-LD
Agile methodologies
NodeCenter For BTC Assessors 2019-01-15 - 2019-09-10
- Software engineer
- Full stack developer
Application to manage blockchain / DLT nodes deployments in few clicks with an easy to use web interface, based on an Open API documented REST API exposed by a companion app daemon
Docker
REST API
OpenAPI
Python 3.7
Flask
Angular 8
Typescript
GitLab CI/CD
Bitcoin Framework For BTC Assessors & UAB 2017-07-04 - 2018-12-03
- Software engineer
- Library maintainer
Python Bitcoin framework to create transactions with smart contracts (scripts) based on puzzle-friendliness and OOP
Bitcoin
Cryptography
Python 3.6
Unittest
Sphinx
ReadTheDocs
TravisCI
GitLab CI/CD
PyPi
IBC Report Generator For IBC Biomechanics 2015-09-25 - 2018-02-17
- Lead software engineer
- Full stack developer
Desktop application to generate biomechanics reports out of data extracted from third party applications and devices using user-created report templates
Anaconda
Python 2.7
Python 3.4
PyQt 4
PyQt 5
SQL Alchemy
Maria DB
Docker
Police Translator For ISPC 2014-06-27 - 2015-11-18
- Software engineer
- Full stack developer
Hybrid mobile application with a collection of useful phrases for police officers translated from/to English to/from Catalan, with audio pronounciations and that fully works offline. Web application to manage all content and their translations
Linux
PHP 5
MySQL
jQuery
Apache Cordova
HTML4
CSS2
JavaScript
Skills
Frontend: web & hybrid mobile ★★★★☆
Flutter
Angular 11
Redux (flux architecture)
Typescript
Responsive design
Material Design 2
Bootstrap
Jekyll
HTML5
CSS3
Javascript
Backend ★★★★☆
Ruby on Rails
Sidekiq
Typescript
Node.js
Express
OpenAPI
PostgreSQL
Spring Framework (Boot)
Kotlin
Java
Python
PHP
J2EE
Gradle
Maven
Liquibase
MongoDB
DevOps ★★★★☆
Docker
Terraform
GitHub CI/CD
Shell scripting
Travis CI
GitLab CI/CD
Apache JMeter
Heroku
Software architecture ★★★★☆
Clean Code
Clean Architecture
DDD
TDD
Design patterns
Systems administration ★★★★☆
Linux
Arch Linux
Debian/Ubuntu
Bash
Zsh
iptables
OpenVPN
Wireguard
Windows XP+
Project management ★★★☆☆
4+1 Architecture
Agile methodologies
Requirements specification
Use cases diagrams
Languages
Spanish ★★★★★ (native)
Catalan ★★★★★ (native)
English ★★★★☆ (B2 certified)